It’s getting hot in here! Turning up the heat and the hormones makes a female turtle

Featured Scientist: Rosario Marroquin-Flores (she/her/hers), PhD, 2022, Illinois State University. Currently a Postdoctoral Research Associate in the Department of Biological Sciences at Texas Tech University.

A headshot of Rosario. She has long dark curly hair and a big smile.

Birthplace: Albuquerque, New Mexico

My Research: I study temperature-dependent sex determination (TSD) in turtles. Turtles that have TSD will become male, or female, based on the temperature they experience as an egg. 

Research Goals: I have recently transitioned into a new field of research, Biology Education Research (BER). People who work in BER study how students learn biology in the classroom. I would like to explore new ways of teaching that help students connect their biology content knowledge to real-world problems.

Career Goals: I am interested in teaching and doing research at the university level.  

Hobbies: I enjoy camping, backpacking, and spending time with my partner and my pets. 

Favorite Thing About Science: I enjoy the autonomy of science. I like that I get to decide what I want to study. I get to ask my own questions and find my own answers. I also like how dynamic it is. Every day I get to do something different. I’m very busy, but I’m never bored! 

Scientist Upbringing: I have always had a passion for living things. I used to sit in the grass in my front yard and try to be as still as possible, and just wait for everything around me to come alive. When I was a little girl, those interests manifested in the desire to be a veterinarian. However, when I got into my undergraduate program, I started to do research. My research experiences ignited a deep curiosity that encouraged me to explore living things more deeply.

My Team: I am the first author on this publication, but this has been a collaborative project. My advisors, Dr. Rachel Bowden and Dr. Ryan Paitz, helped me come up with the project, assisted with data analysis, and helped in writing the publication. My wonderful lab mate, Anthony Breitenbach, helped me organize my eggs into treatments, complete dissections, and provided lots of emotional support and very loud jokes.

Organism of Study: I study the red-eared slider turtle (Trachemys scripta)

A recently hatched turtle. The turtle is still half inside the egg and is roughly the size of a golf ball.
A hatchling red-eared slider turtle emerging from its shell

Field of Study: Eco-physiology

What is Eco-Physiology? Eco-physiology is the study of the relationship between the body and the environment. In my research, I study how temperature affects the way turtles develop in the egg.

QR code to the original publication

Citation: Marroquín-Flores, R.A., Paitz, R.T and Bowden, R.M., 2022. Temperature fluctuations and estrone sulfate affect gene expression via different mechanisms in a species with temperature-dependent sex determination. Journal of Experimental Biology, 225(16), p. jeb244211.

Research At A Glance: Living things are closely connected to the world around them. External conditions like the environment, light, or water availability can affect how animals develop. At the same time, internal conditions like hormones or metabolism, can also affect how animals develop. In my research, we focused on how temperature influences development in a species of turtle. Animals that have temperature-dependent sex determination (TSD) will develop as male or female based on temperature. For our research, we studied the red-eared slider turtle, a species of reptile with TSD. In the red eared slider turtle, warm temperatures of about 31°C will result in females and cool temperatures of about 26°C will result in males. Temperature can lead to male or female development when some genes are turned on and off. In previous studies, researchers have found two genes that are important for regulating male development, Kdm6b and Dmrt1. Kdm6b is a gene that is sensitive to temperature and is responsible for turning on the Dmrt1 gene. Dmrt1 is responsible for activating the male pathway by turning on other genes that help the turtle to develop as male. When turtle eggs are exposed to cool temperatures, Kdm6b and Dmrt1 are turned on, but when eggs are exposed to warm temperatures, they are turned off. While temperature is important, hormones also play an important role in development for the red-eared slider turtle. Mother turtles will leave female hormones, like estrogens, in the eggs when they are laid. Eggs that are laid later in the nesting season have more estrogens and are more likely to develop as female. Previous studies show that estrogen can affect which genes are turned on or off. In this study, we explore how temperature and a specialized form of estrogen, called estrone sulfate, effect genes and development in the red-eared slider turtle.

Highlights: For this research, we placed turtle eggs in a temperature-programmed incubator to mimic the temperature that turtle eggs experience in nature. In the wild, temperatures go up during the day and down at night, so we programmed our incubator to do the same. Our goal was to understand how genes respond to these temperature changes. We started with three experimental treatments. In the first treatment, we initially incubated eggs using cool temperatures, then shifted the eggs to warm temperatures during the window of development that turtles are most sensitive to temperature. This treatment was designed to create females. In the second treatment, we incubated the eggs using cool temperatures and added our hormone, estrone sulfate, to the eggs to create females. In the third treatment, we incubated eggs using only cool temperatures to create males. The full experimental design is pictured below in Figure 1.

Figure 1. The experimental design for the study. The eggs were randomly placed into three experimental treatments as show above. The grey ovals represent eggs. The dropper shows that we added either estrone sulfate or ethanol to the top of each egg. Ethanol was used as an experimental control. The blue lines represent a cool, male temperature. The red lines represent a warm, female temperature. The small green circles show when we sampled the eggs. Adapted from Marroquín-Flores et al. 2022.

We sampled eggs at several points. We sampled during the window of development that turtles are most sensitive to temperature. The time that we sampled was critical because this is when we expected to see a change in which genes were turned on. We also let some of the eggs hatch to make sure that our experimental treatments worked. We wanted to make sure that our warm temperature treatment led to females, that our estrone sulfate treatment led to females, and that our cool temperature treatment led to males.

At the end of the experiment, we found that our treatments were effective. Eggs that were incubated under warm temperatures or treated with estrone sulfate hatched as female and eggs that were incubated under cool temperatures hatched as male. The results for the Kdm6b gene are outlined in Figure 2. Kdm6b responded to temperatures in the way that we expected. As you can see in Figure 2, there was more Kdm6b in the eggs when they were incubated under cool temperatures and less when they were under warm temperatures. However, Kdm6b did not respond to estrone sulfate as we expected. The Kdm6b gene was still turned on in the estrone sulfate treatment. Figure 2 shows Kdm6b expression looked the same between eggs incubated under cool temperatures and those that had estrone sulfate added to the eggs. This was an interesting result because Kdm6b is a male gene, but it was turned on even though the turtles were hatching as female. These findings suggest that Kdm6b responds specifically to cool temperatures.

A data figure that shows the results of the Kdm6b gene. The lines for the male temperature treatment and treatment with estrone sulfate are close to each other at each of the three sampling points. The line for the female temperature treatment is much lower than the other two, very close to zero.
Figure 2. The results for the Kdm6b gene. The blue line with the squares show the treatment where eggs were incubated under cool, male temperatures only. The orange line with the circles shows the treatment where eggs were incubated under cool male temperatures but also had estrone sulfate added to the eggs. The red line at the bottom with the triangles shows the treatment where eggs were shifted to a warm, female temperatures during window of development that turtles are most sensitive to temperature. The y-axis shows how much Kdm6b was present in the sample and the x-axis shows when the eggs were sampled, where 1 is early in the window of development that turtles are most sensitive to temperature and 3 is later. Adapted from Marroquín-Flores et al. 2022.

The results for the Dmrt1 gene are outlined in Figure 3. Dmrt1 responded to temperature the way that we expected. Dmrt1 tends to turn on later during the window of development that turtles are most sensitive to temperature.  In Figure 3, there is more Dmrt1 in eggs that are incubated under cool, male temperatures and this increase happens later in development, near our last sampling point. There is also less Dmrt1 in eggs incubated under warm, female temperatures. However, Dmrt1 did not respond to estrone sulfate the way we expected. Interestingly, the amount of Dmrt1 was low in eggs that had estrone sulfate added to them, and even lower than eggs that were incubated under warm temperatures. These results suggest that Dmrt1 responded more strongly to our female hormone than our female temperature. Recall that Kdm6b is responsible for turning on Dmrt1. Our results suggest that estrogens can override the effect of Kdm6b on Dmrt1 and lead to female development.

A data figure that shows the results for Dmrt1. The lines for the female temperature treatment and the male temperature treatment are equal at the first two sample points, but the line for the male temperature treatment increases dramatically at the third sampling point. The line for the estrone sulfate treatment is lower than the other two treatments at each sampling point.
Figure 3. The results for the Dmrt1 gene. The blue (square), orange (circle), red (triangle) lines correspond to the male temperature treatment, estrone sulfate treatment, and female temperature treatment, respectively. The y-axis shows how much Dmrt1 was present in the samples and the x-axis shows when the eggs were sampled, where 1 is early in the window of development that turtles are most sensitive to temperature and 3 is later. Adapted from Marroquín-Flores et al. 2022.

What My Science Looks Like: ­­­The steps involved in our research are pictured in the image below. To sample the eggs, we dissected bipotential gonads from undeveloped turtles. Bipotential gonads are tissues that will later develop into either ovaries or testes. They are located on top of another tissue that will later become the kidney. Even though they have not yet become ovaries or testes, the bipotential gonads will still turn on genes that show if the turtle is on the path towards male or female development. After dissection, we isolate the DNA from the tissue. We can then target our genes of interest using small pieces of DNA, called primers. Primers will only bind to strands of DNA that match the gene of interest. Once this step is done, we use a lab technique called Quantitative polymerase chain reaction (qPCR) which makes many copies of the gene of interest and counts how much of the gene is in a sample. qPCR is accomplished with the help of computers. The samples are prepared using a solution that contains an ingredient that will glow each time a new copy of the gene is made. A computer then will count the number of times the light is emitted to count how many copies of the gene exist in the sample. The computer continues to make copies of the gene until it reaches a certain threshold. If it takes a long time to reach the threshold, that means that there is a smaller amount of the gene in the sample. If it takes a short amount of time to reach the threshold, that means that there is a larger amount of the gene found in the sample. This method is what allowed us to figure out how much of the Kdm6b and Dmrt1 gene was present in the bipotential gonads of turtles in each treatment.

A graphic that shows the steps to results from qCPR. The first image is a cartoon turtle with a red circle around the lower abdomen, where the gonads are. The bipotential gonads are placed in test tube and the DNA is isolated. The final step is to run the DNA on a qPCR machine. When the DNA amplifies, is looks several curves on a computer screen.
The steps that were taken in the research presented in the published paper.

The Big Picture: As a result of climate change, the environment is becoming unpredictable, and the earth is becoming warmer. We are expected to experience heat waves that are longer lasting and of a higher intensity. For many animals, development and survival are closely tied to the environment. That is why it’s crucial to understand how external conditions, like temperature, and internal conditions, like hormone signaling, can affect development. I used the red-eared slider turtle because it has a common form of sex determination. While our research focused on the red eared slider turtle, our findings can be also applied to other reptiles, including sea turtles, which are critically endangered. Our research is also important because of the type of hormone that we used in our research. Estrogen comes in many forms. One of these forms, estrone sulfate, is often considered an inactive form of estrogen. Our findings counter this theory. Our findings suggest that estrone sulfate was able to affect Dmrt1, an important gene in the male pathway. Estrone sulfate was also able to override the effect of male temperatures to induce female development in turtles. Our research opens the door for many exciting opportunities and work to be done with the hormone, estrone sulfate.

Decoding the Language:

Autonomy: Autonomy is the ability to act on your own values and interests. It is having the power to make your own decisions independently and do the things that are important to you.

Bipotential gonads: Bipotential gonads are tissues that can be found inside an embryo, or an undeveloped animal. The bipotential gonads are still early in development and will go on to become either the ovaries or the testes when the animal finishes developing. In red eared turtles, the bipotential gonads are located on top of a tissue that will later become the kidney. Adult ovaries will produce female hormones, like estrogen, and adult testes will produce male hormones, like testosterone.

Climate change: Climate change are shifts and changes in global weather patterns that happen over a long period of time. It refers to the different increasing global temperatures like drought and rising temperatures that cause heat waves. Humans use of fossil fuels that release greenhouse gasses into the atmosphere, which contributes to climate change.

Data analysis: Data analysis involves examining and comparing data (in this case, the amount of the Kdm6b in turtles) across groups (known as “treatments”) in an experiment. Data analysis is important to draw accurate and meaningful conclusions after an experiment.

Deoxyribonucleic acid (DNA): DNA is a molecule that’s like a blueprint of the body. It contains all the instructions that the body needs to grow, develop, and function.

Doublesex and mab-3 related transcription factor 1 (Dmrt1): Dmrt1 is a gene that is important for male development in many species. It helps male reproductive organs grow. In turtles, Dmrt1 is turned on by Kdm6b. If Dmrt1 is intentionally turned off by researchers, then the turtle will develop as female.

Estrogen: Estrogen is a female hormone that is produced by the ovaries. It can exist in three forms: estradiol, estrone, and estriol. In this study, we looked at the effects of one type of estrogen, estrone-sulfate.

Estrone sulfate: Estrone sulfate is the combination of estrone, a form of estrogen, and a sulfate group. The conjugated form of this estrogen (estrone + a sulfate group) is often considered to be inactive. However, our findings show that estrone sulfate can make changes in the body.

Experimental control: An experimental control is a technique used to minimize, or “control”, unintended effects of a particular treatment. In this research, estrone sulfate was dissolved in ethanol and applied to eggs in the hormone treatment. This means that eggs in the hormone treatment were exposed to both estrone sulfate and ethanol. To ensure that the only differences between eggs in the hormone treatment and those in the other treatments was due to hormones, we applied ethanol to eggs in the other treatment groups as a control.

Gene: A gene contains the Information that will determine your traits and characteristics and it also contains the instructions that your body needs to make proteins. 

Hatchling: A hatchling is any animal that was recently born from an egg.

Hormone: A hormone is a chemical messenger that travels through the blood to induce changes in the body. There are many types of hormones. For example, testosterone is a male hormone that is produced by the testes and leads to the development of masculine features, like a beard. Estrogen is a female hormone produced by the ovaries and leads to feminine features. Cortisol is a stress hormone that is released during our fight or flight response.

Histone H3 lysine 27 (H3K27) demethylase (Kdm6b): Kdm6b is a gene that is important for male development in TSD species. When turtles are incubated under cool, male temperatures, the amount of Kdm6b increases. If turtles are incubated under male temperatures, but Kdm6b is intentionally turned off by researchers, then the turtle will develop as female. Kdm6b is important because it responds directly to temperature, and it turns on another gene that is critical for male development.

Primers: Primers are short pieces of DNA that can be specifically designed in the lab to match a small section of a gene. This allows researchers to target the specific gene of interest from a large pool of DNA that contains many genes.

Quantitative polymerase chain reaction (qPCR): qPCR is a laboratory technique that is similar to Polymerase chain reaction (PCR) in that it involves making many copies of DNA. The only difference is that qPCR takes this one step further by counting how much of a specific gene is in a sample. It involves making several copies of a gene until it can be detected by a computer, then counting how much is there.

Temperature-dependent sex determination (TSD): TSD is a special form of sex determination where temperature will determine whether an animal will develop either as a male or female. For some animals, like the red-eared slider turtle, warm temperatures create females and cool temperatures create males. For other animals, it’s the exact opposite. Animals, like the American alligator, have males that are produced at high and low temperatures, but females are produced at intermediate temperatures.

Learn More:

A YouTube video that describes how climate change can affect animal species

A brief article and YouTube video from the University of Wisconsin – Eau Clair on estrogen pollution in water systems

A YouTube video that describes how Kdm6b and Dmrt1 regulate sex determination

A YouTube Video that explains how PCR and qPCR work.

Synopsis edited by Maisam Yousef, B.S. 2019, Illinois State University, Rebekah Jackson, B.S. 2022, Indiana University-Purdue University-Indianapolis.

Download this article here

Please take a survey to share your thoughts about the article!

Tackling Tennessee Tornadoes

Featured Scientist: Jayme Walters, she/her/hers, PhD, Utah State University (Graduated from University of Tennessee with my PhD in 2020)

Dr. Jayme Walters stands in a field with a mountain in the backdrop. She has her hands on her hips.
Dr. Jayme Walters, Assistant Professor of Social Work at Utah State University

Birthplace: Southern Illinois

My Research: The focus of my research is to understand and improve the well-being of disadvantaged and oppressed individuals and families in Rural America. I study rural nonprofits and other organizations in persistently poor counties, their ability to accomplish their missions, and how being in impoverished, rural communities impacts their work. My work contributes to rural-focused literature in social work and nonprofit management. Using research to identify potential connections between place-based issues and organizational capacity is important to ensure that rural nonprofits can accomplish their goals and serve their communities. 

Research Goals: Moving forward, I will continue to develop research and interventions to improve the capacity and effectiveness of nonprofits so that they may successfully serve rural communities. I hope to serve as an advocate for organizations in rural communities to share their incredible impact and help to communicate their needs to funders.

Career Goals: I love being a professor! I hope to continue to be a researcher, teacher, and serve our communities in an effort to make positive changes.

Hobbies: Going to concerts, shopping, listening to music and audiobooks, hiking, and being with my family.

Favorite Thing About Science: There is some comfort in the predictability of the research. But often, what comes out of the process is unexpected, and that’s exciting. Being able to contribute to the generation of knowledge is a privilege.

Field of Study: Social Work

What is Social Work? Social work is a practice-based profession that promotes healthy well-being of people and their communities. We engage, in a collaborative way, with communities to provide assessment, intervention, and evaluation to ensure social change and improvement, particularly for individuals and families who are most vulnerable and oppressed.

Scientist Upbringing: I hated science when I was a kid. My brain just struggled with “hard sciences” – and some of that was lack of confidence and believing that I was not smart enough. Also, I was told regularly that science was a “boy” subject; as a girl, my place was to appreciate English and literature. I didn’t realize until I was in college that social sciences were a “thing.” Actually, it wasn’t until I was in undergraduate social work research class that I realized I liked the research process, and I could make a career of it. I appreciate the mentoring of my first research professor, Dr. Wayne Paris, who not only started my interest in research but also provided much-needed encouragement. 

My Team: The work related to social response to tornadoes was part of my PhD studies. I worked alongside my mentor, Dr. Lisa Reyes Mason, and her research collaborator, Dr. Kelsey Ellis. These projects with Dr. Reyes Mason and Dr. Ellis helped me to understand the research process from start to finish. This work also provided insight to place-based issues and research, which is a major component in my main line research. They are excellent mentors and allowed me to lead a few studies which gave me confidence and skill to lead my own work now.

Supporting Scientist: Dr. Kelsey Ellis, PhD, University of Tennessee.

Dr. Kelsey Ellis storm chasing in 2006. Dr. Ellis smiles at the camera, wind blowing in her hair. There is an active tornado in the background.
Dr. Kelsey Ellis, Associate Professor of Geography at University of Tennessee Knoxville

Birthplace: Baltimore, Maryland

My Research: I study the climatology of atmospheric hazards, including tornadoes, hurricanes, heat, and others.

Research Goals: I want to continue to study hazards in an interdisciplinary nature so as to make the biggest difference for public safety.

Career Goals: I am very happy in my current department and hope to help lead it to a successful future.

Hobbies: Baking, exercising, playing with my dogs and kiddos.

Favorite Thing About Science: Discovering new things that no one has ever known before.

Scientist Upbringing: I always had an interest in the weather and thought I would be a television meteorologist, but once I started doing research I loved it!

My Team: This is one paper out of many that came from funding we had from the National Oceanic and Atmospheric Administration (NOAA) from a project called VORTEX-Southeast, which aims to study tornadoes in the Southeast through an interdisciplinary nature. I was the climatologist in the group, and this specific paper was led by the Social Workers.

Field of Study: Geography

What is Geography? Geography is the study of the physical features of the earth and its atmosphere, and of human activity as it affects and is affected by these, including the distribution of populations and resources, land use, and industries.

Check Out My Original Paper: “Examining patterns of intended response to tornado warnings among residents of Tennessee, United States through a latent class analysis approach”

A QR code that links to the article in the International Journal of Disaster Risk Reduction.
QR code to original publication

Citation: Walters, JE, Mason, LR, Ellis, KN. (2018). Examining patterns of intended response to tornado warnings among residents of Tennessee, United States through a latent class analysis approach. International Journal of Disaster Risk Reduction. 34: 375-386.

Article written by Lesley Knox (she/her), sophomore, Rachel McCarthy (she/her) sophomore, Driana James (she/her) sophomore, and Jacob Hollenhead (he/him) freshman, Pellissippi State Community College. Student authors were enrolled in the Fundamentals of Communication (COMM 2025) at Pellissippi State Community college during the Spring 2022 term.

Research At A Glance: With respect to tornados, the United States is the most active place in the world. The southern portion of the U.S. has seen a high number of fatalities. Research suggests that this can be attributed to residents not seeking appropriate shelter. This study examines how likely residents are to respond to tornado warnings, with the goal of implementing early warnings that will reach those most at risk. The goal is to help the National Weather Service (NWS) identify those who are most at risk, in what ways they are most likely to be targeted in an emergency, and if further public education would be helpful.

In this study, the authors asked participants questions about how they respond to tornado warnings when and if they receive weather notifications. They learned about interesting factors that influence how people respond. People ignore tornado warnings for several reasons: they don’t have the financial ability to leave, they don’t have proper transportation, or they don’t have a safe place to go. But some people don’t have faith that the weather has been predicted correctly or how seriously to take it, because of false alarms in the past. People often wait too long to act or take shelter, and these actions can result in death. The findings identify a group of people who are at risk of not seeking safety after a tornado warning. There is a correlation between the number of warning notifications and a positive safety action for various reasons, including being elderly, not possessing smartphones, or being harder to reach in an emergency. Misinformation also plays a role. Some people have been through a tornado before and were unharmed. Others were unharmed after a tornado and thought that bodies of water or large buildings protected and would continue to protect them. These experiences influence what they believe will happen in future tornados. The NWS can use this information to target the people most at risk to try more ways of notifying them and to educate them about seeking safety in a tornado.

Highlights: In this study, the authors randomly surveyed 1126 people in Memphis, Nashville, and Knoxville, Tennessee. The survey included people who had cell phones and those that had landlines. To survey participants, the researchers used a computerized technology that interviews people over the telephone. Participants were randomly assigned a daytime or nighttime scenario, then asked what they would do if they received a tornado warning. The purpose of the survey was to understand how people respond to a tornado warning, regardless of when it might be received. The authors divided the participants into 3 groups based on their answers to the survey: tech users, typical actors, and passive or non-reactors (Figure 1). Typical actors were the largest group in the study. Typical actors were people who reacted to a tornado warning by looking for more information on the television, through the radio, or sometimes on the internet. Typical actors tended to be middle-aged people who were married or living with a long-term partner. They had access to a basement or storm shelter and had a higher income than other groups. Typical actors made up 54% of the daytime survey participants and 68% of the nighttime survey participants. Tech users were people who would respond to tornado warnings by looking for more information on the internet or through an app and were likely to seek shelter. Tech users were usually people who owned a smartphone and had young children living in the home. They made up 29% of daytime survey participants and 26% of the nighttime survey participants. Passive reactors were people who were given the daytime scenario and would not take any safety measures after receiving the warning. However, passive reactors tended to speak to friends, family, or others about the warning. Seventeen percent of the daytime survey participants were passive reactors. Non-reactors were people given the nighttime scenario who would do nothing after receiving a tornado warning. Only 4% of the nighttime survey participants were non-reactors.The smaller group of passive reactors and non-reactors were mostly made up of senior citizens, females, and long-term residents of Tennessee. These findings are important because they identify people who do and do not react to the tornado warnings. These findings can help the NWS determine future safety measures.

Pie charts that show the percentage of participants identified as typical actors, tech users, and passive and non-reactors.
Figure 1. The percentage of participants placed in each group in the daytime (above) and nighttime (below) scenarios.

What My Science Looks Like: Figures 2 and 3 show how people stated that they would respond if they received a tornado warning. During the daytime scenario, all participants would look outside at their surroundings or contact friends and family. Even so, there was a big difference between how tech users and how typical actors sought out additional information. There was a 100% probability that tech users would seek more information from the internet, and they were also more likely to contact friends and family. Typical actors were more likely to turn on the tv or radio for more information but had only a 50% probability of using an app on their phones to get more information. Conversely, passive reactors had a high probability of doing nothing after a tornado warning.

A bar graph that shows how tech users, typical actors, and passive reactors would respond to a tornado warning during the daytime
Figure 2. Actions or inactions that participants chose in the study, given the daytime scenario.

During the nighttime scenario, typical actors and tech users responded similarly. Typical actors and tech users were equally likely to get more information from the tv or the radio and were almost equally likely to look outside. However, there was a higher chance that typical actors and tech users would do nothing during the night, likely because people are sleeping or tired. It should also be noted that the non-reactors were less likely to turn on the TV or radio, seek additional information, or contact friends or family, than their daytime passive reactor counterparts. These results are consistent with the information suggesting that tornadoes that occur during the night are more deadly than those that happen during the day. The findings indicate that the group most at risk of harm are the passive reactors or non-reactors. The NWS can take steps to reach this group in the future.

A bar graph that shows how tech users, typical actors, and passive reactors would respond to a tornado warning during the nighttime.
Figure 3. Actions or inactions that participants chose in the study, given the nighttime scenario.

The Big Picture: On average, the United States has more annual tornadoes than any other country. U.S. tornadoes produce property damage, billions of dollars in reconstruction and relief aid, and significant numbers of fatalities each year. The southern region of the U.S. (Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, New Mexico, Oklahoma, Tennessee, and Texas) has experienced 11 of the 25 deadliest tornadoes ever recorded. This experiment examines behavioral patterns in response to tornado warnings among residents in Memphis, Nashville, and Knoxville, Tennessee. The authors found that people who received a warning during the day were more likely to act. They also found that the more notifications someone gets about a tornado, the more likely they are to take safety actions. Participants that were passive or non-reactive were found most at risk. The NWS is now considering adding or increasing warning messages to encourage others to reach out to passive or non-reactors. The information from this study can be used better target at-risk individuals in the future.

Decoding The Language:

Behavioral patterns: Behavioral patterns refers to how an individual or group responds to an object or a situation. It is repeated behavior. In the context of this article, a behavioral pattern would be how a person regularly responds when they receive a tornado warning.

Climatologist: A climatologist is a scientist who studies weather patterns over long periods of time.

Climatology: Climatology is the study of the atmosphere and weather patterns over long periods of time.

National Weather Service (NWS): The National Weather service is a federal agency that provides all climate forecasts and warnings in the United States.

Non-reactor: A non-reactor was a study participant interviewed during the nighttime. These were people who would not move to safety or seek out further information from any sources in the event of a tornado warning.

Organizational capacity: Organizational capacity refers to an organization’s ability to perform its designated duties. For example, the NWS has to be able to coordinate across its regional offices to make sure that people receive information about tornados in their local areas and to receive those warnings in a timely fashion, with the goal of saving lives. The organizational capacity would be the ability to the NWS to take each of the necessary steps to achieve this goal.

Passive reactor: In the context of this study, passive reactors were people given the daytime survey and who unlikely to act in the event of a tornado warning. The had a “passive” response when they receive a tornado warning.

Place-based issues: Place-based issues are problems specific to certain places or regions that can be addressed by improving the conditions of the entire community associated with the area. For example, improving the health outcomes of a region may involve bringing in community stakeholders to improve hospitals, recreational facilities, and housing, with the goal of holistically creating a healthier community.

Probability: Probability is a mathematical term that describes how likely it is that an event will occur and is represented by a number that falls between 0 and 1. If the probability is high, or closer to 1, then it is more likely to occur. If the probability is low, or close to 0, then it is less likely to occur.

Social work: Social work is a profession that strives to support the basic needs of people, families, and communities. Social workers might work as therapists, counselors, researchers, case workers, care takers, administrators, community organizers, and more.

Tech user: A tech user was a study participant who was likely to respond to a tornado warning by actively using technology. These participants would use the Internet or smartphone app to gather more information.

Typical actor: A typical actor was a study participant ho was likely to respond to a tornado warning by seeking out further information by turning on the TV or listening to the radio.

Learn More:

The Fujita Scale of tornado damage intensity from the National Weather Service.

Information on tornado alerts from the National Weather Service.

A research article on messaging strategies used by weather forecasters:

Liu, B., Atwell Seate, A., Iles, I., & Herovic, E. (2020). Tornado Warning: Understanding the National Weather Service’s Communication Strategies. Public Relations Review, 46(2), 101879.

Synopsis edited by Rosario Marroquin-Flores (she/her), PhD 2022, Illinois State University and Katy Ross (they/she), PhD 2019, Ohio University.

Download this article here

Please take a survey to share your thoughts about the article!

Synopsis Authors:

Lesley Knox (she/her) sophomore at Pellissippi State Community College.

Lesley with her wife sit on a bench. Their and daughter sits between them.

Lesley has always lived in Tennessee, but resides in Knoxville, TN with her wife, Daisy, and daughter, Lainey. She enjoys spending time with her family, cooking, and reading. Lesley is studying Imaging Sciences with the hopes of becoming a doctor in radiology.

Rachel McCarthy (she/her), sophomore at Pellissippi State Community College.

Rachel holds her daughter. There is a lake and mountains in the background.

Rachel has traveled and lived all over the world, but now has settled in Oak Ridge, TN, close to her parents, siblings, and extended family. She is a mother to her daughter, Aria, and they enjoy baking, kayaking, playing with their 2 dogs, and playing piano together. Rachel is studying Business Management, teaches music to school-aged children, and volunteers in her community and church.

Driana James (she/her), sophomore at Pellissippi State Community College.

Driana holds her daughter, while her daughter kisses her cheek. There is a prairie in the background.

Driana plans to have an A.A.S. in Business Management come May! Driana has had a license through Tennessee as an Aesthetician since 2017. She hopes to take her career into marketing or data analytics.  She was blessed with a best friend, and a daughter in January 2019. She spends her days being a mom and student as of right now. Driana longs for the days we can have barbecues, spend all day at the parks, and have 9:00 p.m. sunsets since summer is her favorite season.

Jacob Hollenhead (he/him), freshman at Pellissippi State Community College.

Jacob and his girlfriend smile at the camera. There is an ocean with a setting sun in the background.

He was born and raised in Knoxville, Tennessee where he still resides. He is going to school for Architectural Design Technologies, with hopes of designing houses in the future. Jacob enjoys playing his guitar, spending time with his niece and nephew, and fishing with his dad when the weather permits it.

Sustainable Use of Recycled Glass in Pavement Systems

Featured Scientist: Saurabh (Mobi) Singh (he/him/his), Master of Business Administration 2017, Inactive M.S. student, Department of Technology, Illinois State University.

A picture of Saurabh standing in front of a construction site.
Mobi Singh at a construction site in Bloomington, IL

Birthplace: Jhajjar, Haryana, India

My Research: The research, led by Dr. Pranshoo Solanki, involved creating unique types of construction materials out of waste products like glass and rubber. The goal of the project was to support sustainability and help reduce pollution. The cement industry is one of the leading producers of greenhouse gases and our research can help the industry make sustainable and environment-friendly decisions.

Research Goals: Short term, I want to engage in research that challenges the status quo to help industries make choices that will make the world a cleaner and better place. Long term, I want to engage in research that will use innovative technologies to address child hunger. I am also interested in researching the role of privacy concerns and emotions in social media advertising at Kent State University in Ohio. 

Career Goals: I like to dream and try new things. There is no specific career path that fits all my skill sets but I wish to be a full-time scholar for the rest of my life. Being a university professor and helping other students grow intellectually is one of my long-term career goals. As I grow older, I would like to spend more time giving back to my community. In later years, I wish to support the costs of higher education for those who are not able to cover the costs themselves.

Hobbies: I enjoy travelling to other countries, cooking, meeting new people, and community service.

Favorite Thing About Science: Science is exciting because it shifts paradigms towards better methods and applications of knowledge.

Field of Study: Material Science

What is Material Science? Material science is the study of human-made materials. We study the chemical and physical properties of these materials and figure out how they can be used. For example, one practice could be to take recycled materials and see how they might be used in common household items.

My Team: The research was conducted in Turner Hall at Illinois State University. The research team was led by Dr. Pranshoo Solanki. The team had an external co-investigator named Dr. Gaurav Sancheti from Manipal University in India. I actively worked with Dr. Pranshoo Solanki in the construction management laboratory to test samples of concrete.

Check Out My Original Paper: “Sustainable Use of Waste Glass in Pavement Systems–Review, Limitations and Potential Application”

QR code that links to the original publication.
QR code to the original publication

Citation: Solanki, Pranshoo, Gaurav Sancheti, and Saurabh Singh. “Sustainable Use of Waste Glass in Pavement Systems–Review, Limitations and Potential Application.” The Journal of Solid Waste Technology and Management 47.2 (2021): 235-251.

Research At A Glance: The United States (U.S.) transportation sector is one of the main sources of greenhouse gas emissions and energy consumption in the U.S. According to the Environmental Protection Agency (EPA), the U.S. is the third largest producer of cement, and cement is the second most consumed substance in the world (after water). The cement industry is the third largest source of industrial pollution in the U.S. and is responsible for emitting more than 500,000 tons of greenhouse gases per year. Cement is one of the raw materials used to make pavement. As cement is a leading contributor of industrial pollution, it has become increasingly clear that our use of pavement has had a negative impact on the environment. As a result, many researchers have started to explore how recycled materials might be used in pavement. For example, usage of recycled glass in pavement has attracted a lot of interest as an alternative to current methods. According to the EPA, 11.5 million tons of glass is produced in the U.S. every year, but 60% of it ends up in landfills. However, when glass is finely ground, it can be used as a substitute for certain components of cement. In our paper, we reviewed potential uses of recycled glass as a pavement material and how the glass might affect the performance of the pavement. Overall, our study found that recycled glass could be used as a pavement material. This means that we could divert large amounts of glass headed to landfills to use as a construction materials.

Highlights: Fly ash has traditionally been used as a partial replacement for cement in many construction materials, like concrete and other controlled low strength pavement materials. Fly ash is a fine powder that is created as a by-product of coal power plants. There have been numerous closures of coal power plants in the past few decades, and this has disrupted the supply of fly ash to the construction industry. Recycled glass powder can be used in place of fly ash in pavement construction and can help to reduce the industry’s reliance on cement. Our study tested the feasibility of using recycled glass powder in lieu of fly ash

To test this, we substituted the fly ash in the cement with a specific type of recycled glass, called ACAS.  We then tested the material for its compressive strength. Compressive strength refers to the amount of pressure that a solid material can handle before it cracks. We also used glass of varying thickness to see if more finely ground or more coarsely ground glass would be best to improve the compressive strength of the pavement. The results in Figure 1 show that when 100% of the fly ash inside of the cement was replaced with finely ground glass, the compressive strength of the pavement improved the most.

Figure 1. This graph displays the results of experiments that tested the compressive strength of the samples. ACAS is a type of fine recycled glass and the three lines depict how the compressive strength varied with different blends of fine and coarse glass. The y-axis shows the compressive strength and the x-axis shows the percent of cement that was replaced with ACAS glass. Figure adapted from Solanki et al. 2021.

Next, we tested the material for its flow consistency. Flow consistency refers to the ability of freshly mixed concrete to flow into empty spaces before it sets. It is used to measure how much the low strength pavement materials flow naturally when they are used to fill trenches and pavements. Similar to the previous experiment, we replaced the fly ash inside of the cement with different amounts of finely or coarsely ground glass. The results in Figure 2 show that the flow consistency was highest when 50% of the fly ash was substituted with finely ground glass.

Figure 2. This graph displays the results of experiments that tested the flow consistency of the samples. The y-axis shows the flow consistency and the x-axis shows the percent of cement that was replaced with ACAS recycled glass. Figure adapted from Solanki et al. 2021.

What My Science Looks Like: In this paper, we suggest that recycled glass can be used as a replacement for fly ash in cement and we test the quality of the new material. In the image below, a sample of controlled low strength pavement material is being tested for its compressive strength.

An image of a cylinder piece of cement. The cement is between two metal pieces attached to an electrical source. The top of the machine pushed down to create force, which is measured to determine the compressive strength.
In this image, we test the cement for its compressive strength at the construction management lab at Illinois State University. The sample contains recycled glass powder in place of fly ash.

The Big Picture: Our research can help reduce pollution in many ways. We suggest alternatives to concrete and provide proof that these alternate materials are effective. We show that recycled glass can improve the properties of concrete. Glass can be a cost effective alternative for the transportation industry and we hope that the industry will adopt these new materials. We offer a green and cost effective alternatives to certain parts of cement and our goal is to reduce current levels of pollution.

Decoding the Language:

Compressive strength: Compressive strength can be defined as maximum compressive stress that a solid material can sustain before fracture.

Environmental Protection Agency (EPA): The EPA is a United States federal government agency whose mission is to protect human and environmental health.

Flow consistency: The flow consistency is a measure of the ability of freshly mixed concrete to flow into empty spaces before it sets.

Fly ash: Fly ash is a fine powder that is made from burning pulverized coal. It is used in concrete to improve workability, strength, and durability.

Greenhouse gas: Greenhouse gases, such as carbon dioxide and methane, trap heat inside the Earth’s atmosphere and can destabilize global weather patterns.

Low strength pavement materials: Low strength pavement materials have a lower concentration of cement as compared to regular pavement material.

United States (US) transportation sector: The US transportation sector is a subsector of the government that deals with all types of transportation, including roads, railways, air travel, and waterways.

Learn More:

United States EPA information on the health and environmental effects of cement

United States EPA information on coal ash

Synopsis edited by Ian Rines, BS 2018, Wofford College, Elyse McCormick, MS (Anticipated 2022), Illinois State University, and Rosario Marroquin-Flores, PhD (Anticipated 2022), Illinois State University.

Download this article here

Please take a survey to share your thoughts about the article!

Going off the rails: Soras increase alarm calling when they hear owls, but not ducks

Featured Scientist: Daniel Lorenz Goldberg (he/him/his), PhD (Anticipated December 2021), Illinois State University, Biological Sciences.

Daniel looking at the camera and pointing to a sign that reads “Illinois State University RAIL COUNT”
Daniel in his office in Illinois State University Science Laboratory Building with his official research vehicle plaque.

Birthplace: Riverside, California

My Research: I study vocal behavior and how it evolved in a group of birds called rails. Rails vocalize frequently at night and in dense vegetation to communicate with each other.

Research Goals: I am interested in pursuing research in bird conservation after I graduate. I hope to learn more about birds to protect them and their habitats. My dream is to increase public understanding about birds by sparking interest through birdwatching.

Career Goals: I aim to do a combination of research and teaching as a university professor.

Hobbies: I enjoy birdwatching, hiking, swing dancing, and tabletop games with my friends.

Favorite Thing About Science: I love the vast amount of primary literature that we have at our fingertips as scientists. There have been so many discoveries that have been documented, and we can  access it by reading about it in books or online. If you have an interesting research question, chances are good that there is some background information out there to get you started!

My Team: This project was a group effort, though I am the first author on the published article. My advisor Dr. Angelo Capparella helped me develop the project, while Dr. Mike Ward provided field equipment. Both professors provided advice on writing the article. My hardworking undergraduate, Toby Bassingthwaite, assisted with fieldwork and transporting our equipment, and she also knew where to hunt down some delicious food in the Chicagoland area!

Organism of Study: I study the Sora (Porzana carolina), a common rail in Illinois.

A photo of a Sora (Porzana carolina). It is a brown bird with a bright yellow beak, and it is standing with its feet in the water.
A photo of a Sora (Porzana carolina). Photo credit: Tim Lindenbaum, The Nature Conservancy

Field of Study: Behavioral Ecology

What is Behavioral Ecology? Animal behavior is shaped by an animal’s habitat and its interactions with other organisms. Behavioral ecology is the study of how an animal’s behavior affects its life and survival. Behaviors that help animals to survive become more common. Behaviors that do not help animals survive become less common.

Check Out My Original Paper: “Calling owl: Rails adjust vocal activity rates in response to changes in predation risk”

A QR code that links to the original publication.
QR code to the original publication

Citation: Goldberg, D.L., Bassingthwaite, T.A., Ward, M.P. and Capparella, A.P., 2020. Calling owl: Rails adjust vocal activity rates in response to changes in predation risk. The Wilson Journal of Ornithology. 132(4):1038–1043.

Research At A Glance: Animals use sound-based communication to signal to each other to defend territories, attract mates, or maintain group contact. However, this communication can be risky because predators can eavesdrop on these sounds. Predators can then home in on the calling animal, and more easily capture and eat it than if the animal had remained silent. Animals can recognize the calls of their predators and often react by reducing the number and rate of their own sounds. For example, birds that are preyed on by raptors fall silent upon hearing raptor calls. One group of birds that has shown little evidence of varying their calling behavior in response to predator sounds are rails. In previous studies, rails have been found to flick their white tails as a visual signal to predators, indicating that the rail is aware that it is being watched. We tested the hypothesis that rails will recognize raptor calls as a predator threat. We predicted that rails would reduce their calling rates when they hear the calls of a raptor, but not when they hear the calls of a different and harmless bird.

The Lake Calumet wetlands near Chicago are a restored habitat that is home to large numbers of rails, including the Sora. We used Autonomous Recording Units (ARUs) to record the calls of rails in 10 locations at the water’s edge of three marshes in the region during the spring breeding season of rails in April 2019. At half of these recording locations, we broadcast the hoots of a raptor, the Great Horned Owl. At the other half of these recording locations, we broadcast quacks of a harmless bird, the Blue-winged Teal duck. We made these broadcasts in the evening, night, and early morning, when rails tend to call the most. At the end of the month, we retrieved the ARUs and counted the number of Sora calls recorded at each of the 10 locations. We then compared the number of calls the rails made per hour at each location. We found that Soras increased their calling rates after broadcasts of the Great Horned Owls but decreased their calling rates after broadcasts of the Blue-winged Teals. This result is the opposite of our hypothesis because birds usually decrease their calling rates when they hear predator calls.

Highlights: Our results indicate that Soras do not recognize Great Horned Owls as a major threat, as the rails were not threatened into silence after the owl broadcasts. This finding made sense because Soras are not the primary prey of this raptor, even though the owl does eat Soras on rare occasions. We found that Soras called at higher levels after the owl broadcast than beforehand. They also maintained high levels of alarm calling for an entire week after the owl broadcast (Figure 1). Other research has found that Soras tend to stay hidden in thick emergent vegetation in their wetland habitats. The plants in this habitat should give rails cover from Great Horned Owls, which use their superb vision to hunt down their prey. If the owls cannot see the Soras, then they are more safely able to make an alarm call because they are not revealing their location.

A line graph shows the frequency of Soras calls per hour from April 13th – 29th. The owl and teal broadcast were done on April 21. The graph depicts an increase in the rate of Soras calls after the owl broadcast.
Figure 1. During the study period of April 13th – 29th, 2019, we recorded Sora calling rate as the number of calls made per hour (y-axis) for several days (x-axis) after owl broadcasts. The dashed line shows the broadcast date when we played either an owl call or a teal call to the soras. The black line shows calling rates of soras that were exposed to owl calls, the grey line shows the calling rate of soras exposed to teal calls.  Figure adapted from Goldberg et al. 2020.

What My Science Looks Like: Rails are shy birds that tend to live in dense emergent vegetation in wetlands, grasslands, or forests. They are difficult to see but are quite loud and produce a variety of sounds that can be heard easily. This allows us to study them using ARUs. ARUs allow us to listen to all the sounds in an area and make recordings when the birds are calling. We can then identify rail calls by their appearance in spectrograms using a computer in the laboratory. This approach cuts down on the amount of time that we need to spend on fieldwork, because instead of going out at dawn, dusk, and night to listen for rail calls, we can simply place an ARU out in the rail habitat to detect calls.

An image of a marsh. There are plants growing in the water, with taller vegetation lining the sides of the marsh.
The view from the north side of Big Marsh Park, looking south past the deployment spot of an ARU, during the spring of 2019. Image adapted from Goldberg and Bassingthwaite 2020.
An image of an ARU. It is a green box mounted on a green pole, with a microphone sticking out the side.
A close-up view of an ARU placed in the field to detect rail calls throughout the day. Image adapted from Goldberg and Bassingthwaite 2019.

The Big Picture: Many rails are endangered, as they have lost habitat due to humans converting wetlands, grasslands, and forests to farm fields and cities. Some rails, like the Sora, are also hunted by humans for food and sport. Because rails produce many calls that are easily recognized, predators can use their calling behavior to identify rail species in the wild. We can use their calls to learn more about how they respond to predators and how they may return to habitats that have been restored. This research is important because it may be used to help rails to increase in number. Conservation of wetland species will benefit other birds and animals that live in those habitats. Wetlands provide many benefits, such as reducing the impact of flooding, improving water quality, and maintaining water levels during droughts. These habitats cannot persist without the presence of a variety of organisms, including rails.

Decoding the Language:

Autonomous Recording Unit (ARU): Autonomous Recording Units (ARU) are battery-powered recording devices. They can be left outside because they have protective covers that shield them from the weather. When they are turned on, they will record all sounds made around them until they are turned off or the batteries run out of power.

Emergent vegetation: Plants that grow in wetlands and stick up partially out of the water. They provide an ideal habitat for rails, which can hide among the plants to avoid detection by predators.

Endangered: Animal species that is at risk of extinction.

Fieldwork: Fieldwork is a type of scientific research that takes place outside of the lab. For my research, fieldwork includes deploying and analyzing sound recordings to listen for rails at the Lake Calumet wetlands near Chicago.

Primary literature: Primary literature is a collection of historical and scientific documents such as books, recordings, or journal articles. Essentially, it is the write-up of information that was collected in a study.    

Rail: Diverse group of birds which includes about 127 different species, including Soras. Most rails are small to medium, and while typically found near marshes they can be found throughout the world.

Raptor: Raptors are meat-eating birds such as hawks, eagles, vultures, falcon, and owls.      

Signal: A signal is a type of communication, such as a sound produced by an animal.    

Sora: Small waterbirds found throughout North America typically in marshes. Usually 19-30 cm in length, they have a grey face and belly while the rest of the body is brown with black & white patches.

Spectrogram: A spectrogram is a type of graph that shows a visual representation of sound, with the frequency of the sound on the y-axis, and the timing of the sound on the x-axis.

Learn More:

For more information on bird call research using ARUs, check out Dr. Mike Ward’s laboratory webpage.

The Macaulay Library of the Cornell Lab of Ornithology, a website devoted to collecting recorded calls of birds and other animals in a database for scientific and general use, was the source of the Great Horned Owl and Blue-winged Teal calls that I broadcast in my study.

There are many articles written about prey animals’ responses to predator sounds. These papers summarize what is known about changes in calling behavior:

Hettena AM, Munoz N, Blumstein DT. 2014. Prey responses to predator’s sounds: a review and empirical study. Ethology. 120:427–452.

Hughes NK, Kelley JL, Banks PB. 2012. Dangerous liaisons: the predation risks of receiving social signals. Ecology Letters. 15:1326–1339.

Zuk M, Kolluru GR. 1998. Exploitation of sexual signals by predators and parasitoids. Quarterly Review of Biology. 73:415–438.

The papers that initially piqued my curiosity about this avenue of rail research:

Randler C. 2006. Disturbances by dog barking increase vigilance in Coots Fulica atra. European Journal of Wildlife Research. 52:265–270.

Randler C. 2007. Observational and experimental evidence for the function of tail flicking in Eurasian Moorhen Gallinula chloropus. Ethology. 113:629–639.

Synopsis edited by Ian Rines, BS 2018, Wofford College, and Emily Kerns, PhD student, University of Wisconsin-Madison, Integrative Biology.

Download this article here    

Please take a survey to share your thoughts about the article!

How do molecules outside the cell affect the nervous system?

Featured Scientist: Jennifer Patritti-Cram (she/hers), PhD candidate (Anticipated: Fall 2021), University of Cincinnati & Cincinnati Children’s Hospital

A selfie of Jennifer in the lab. She has dark hair and brown eyes. There is a microscope in the background.
Jennifer in the laboratory preparing to cut tissue sections of mouse spinal cords and tumors.

Birthplace: Valencia, Venezuela

My Research: I’m interested in understanding how a type of tumor called neurofibromas form in the nervous system. We use mice to study the neurofibroma disease and see how these tumors form. Our goal is to identify genes important to the formation of neurofibromas. We want to provide therapies to patients that suffer from a specific version of this disease: neurofibromatosis type 1.

Research Goals: After obtaining my doctoral degree, I will pursue a career in Intellectual Property Law and Policy.  This means I will not be doing research. Instead, I will use my scientific knowledge to advise scientists on how to protect their scientific inventions.  

Career Goals: I plan to use my knowledge in neuroscience and cancer biology to help scientists protect their inventions. I am also interested in science policy. I plan to use my training to advocate for  policies that increase funds for important research and help to increase Latino representation in science fields.

Hobbies: I like to take hikes with my dogs and watch Netflix.

Favorite Thing About Science: My favorite thing about science is how we are creating new knowledge through research. My most fulfilling time as a scientist is when I discover something new that only I know. Then, as part of my job as a scientist, I get to share that knowledge with other scientists and people around the world.

My Team: My lab is very cooperative. We all help each other with experimental design and with performing experiments. We also have several collaborations with other labs in the United States.

Organism of Study: The house mouse (Mus musculus)

Photo by George Shuklin from Wikimedia Commons

Field of Study: Neurobiology & Cancer Biology.

What is Neurobiology & Cancer Biology? Neurobiology is a type of biology that focuses on the nervous system. Cancer biology focuses on the mechanisms that regulate the spread of cancer. This can include the study of cell growth, the transformation of normal cells into cancer cells, and the spread, or metastasis, of cancer cells.

Check Out My Original Paper: “Purinergic Signaling in Peripheral Nervous System Glial Cells”

QR code that links to the original publication
QR code that links to the original publication

Citation: Patritti-Cram J, Coover RA, Jankowski MP, Ratner N. Purinergic signaling in peripheral nervous system glial cells. Glia. 2021 Aug;69(8):1837-1851. (PMCID: PMC8192487).

Research At A Glance: This article is a review, it summarizes our knowledge of a particular topic. In this review, we address specific ways that cells communicate with each other and how that can control cell function. We focus on a type of molecule called purines, which are located outside of the cell. When purines bind to the cell, they can cause changes in how the cell functions and how it communicates with other cells. To make this change happen, the purine must bind to a specific type of chemical structure called a receptor, which is located on the outside surface of a cell. When the purine binds to a receptor, it can trigger a change in how that cell communicates with other cells. When this happens, it is called purinergic signaling. Our review focuses on purinergic signaling and how it affects a specific cell type in the body called glial cells. Glial cells surround our nerve cells to provide the support and protection that they need to work properly. Our nerve cells transmit information across the body. They help us to interpret tactile information, like touching a door knob, help us to control muscle contractions, and play a role in how we experience pain. In our review, we focus on a particular type of glial cell called Schwann cells.

In this review, we provide a summary of all the known receptors that purines can bind to. We refer to these receptors as purinergic receptors. We also provide a summary of the molecules that turn on to block those receptors, a summary of  all the receptors that purines can bind to in mouse Schwann cells, and explain how they work. The nervous system is made up of two parts, the central nervous system (CNS), which includes the brain and the spinal cord, and the peripheral nervous system (PNS), which connects the rest of the body to the CNS. In our review, we discuss which purines might be found in the PNS. We review the role of purinergic signaling in several diseases and how it may impact how we experience pain. We conclude the review by arguing that scientists should focus on purinergic receptors when we develop drugs to treat diseases that impact the PNS.

Highlights: In this article, we provided a summary about how purinergic signaling happens in normal nerve cells (Figure 1), how purine molecules can impact tumors (Figure 2), and how purinergic receptors can regulate pain (Figure 3). Each figure below gives a summary of the main points made in our article. Figure 1 shows what happens in a normal nerve cell. When nerve cells receive an electrical signal, the axon of the nerve cell will receive and send the signal to other nerve cells, muscles, and glands. The electrical signal triggers the release of different types of purine molecules. These purines bind to purinergic receptors on the surface of Schwann cells to trigger cell responses. Schwann cells will perform different functions based on which type of purinergic receptor becomes bound by the purine molecule.

An image that summarizes what happens in a normal nerve cell. Step 1 shows a cartoon image of a lightning bolt. Step 2 shows the cell body which receives the electrical signal and the axon which passes the signal, with arrows to show that purine molecules are released. Step 3 shows purine molecules hovering around a Schwann cell. The Schwann cell has three different types of purinergic receptors: P1, P2X, and P2Y, all of which lead to slightly different Schwann cell functions.
Figure 1. Purinergic signaling in a normal nerve cell in the peripheral nervous system (PNS) in three steps: 1) the nerve cell is stimulated by an electrical signal, 2) purine molecules are released, and 3) purine molecules bind to purinergic receptors to control how Schwann cells function, grow, and multiply. Figure adapted from Patritti-Cram et al. 2021

Figure 2 shows the roles of purine molecules in tumor cells when they are located in the PNS. Tumors have many purine molecules. These purine molecules activate purinergic receptors in the immune cells inside the tumor. The immune cells will then respond and contribute to fight tumor growth.

An image that summarizes the role of purine molecules in peripheral nerve tumors. The image shows purine molecules, Schwann cells, and immunce cells clustered around a tumor cell. It has an arrow with a list of the effects of purine molecules, including supporting cell growth, regulating blood oxygen levels, stimulating blood vessel growth, and reducing the spread and size of tumor cells.
Figure 2. The role of purine molecules in peripheral nerve tumors. Figure adapted from Patritti-Cram et al. 2021.

Figure 3 shows the roles of purine molecules in regulating our pain response. Purinergic receptors have different roles in pain. Some help alleviate pain and inflammation, while others produce the pain sensation itself. We still need more research to clarify the role of purinergic receptors in pain.

An image that summarizes the role of purine molecules in the regulation of pain, including blocking painful stimuli (toxins, chemicals, adverse temperature), alleviating pain, reducing pain from synthetic opioids, reducing chronic inflammatory pain, reducing skin sensitivity, and regulating thermal sensitivity.
Figure 3. The role of purinergic receptors in the regulation of pain. Figure adapted from Patritti-Cram et al. 2021.

What My Science Looks Like: As part of this paper, we did an experiment to identify the purinergic receptors found in mouse Schwann cells. We isolated the Schwann cells from mice and performed a laboratory technique called reverse transcription polymerase chain reaction (RT-PCR). RT-PCR allows us to count how much DNA is in a sample. In this case, we wanted to know which purinergic receptors were in mouse Schwann cells and how abundant they were.

Figure 4 shows the results of this test when we were looking for one type of purinergic receptor, P2X. Recall that P2X receptors help Schwann cells to communicate with other cells, migrate, and protect the axon of the nerve cell (Figure 1). The x-axis in Figure 4 shows each P2X receptor we found and the y-axis shows the cycle threshold (CT) value. The CT is the number of cycles required for the DNA to be detected in our sample. If a CT value is low, this means that there was more DNA in our sample because it took fewer cycles to be detected. So, in this case, a low CT means that the purinergic receptor was more abundant in our sample. As you can see, the P2X receptor “P2RX4” was the most abundant in mouse Schwann cells, while “P2RX1” was the least abundant. Our results are interesting because we can now give scientists a specific list of purinergic receptors that are present in mouse Schwann cells. This list can provide scientists with insight on how these receptors might impact how Schwann cells function in diseases that affect the peripheral nervous system.

A data figure that shows six P2X receptors found in mouse Schwann cells. The most abundant purinergic receptor is P2RX4, with a CT equal to approximately 5. The least abundant purinergic receptor is P2RX1, with a CT equal to approximately 23.
Figure 4. P2X purinergic receptors in mouse Schwann cells. We found that the following P2X receptors are expressed in mouse Schwann cells:P2RX2, P2RX3, P2RX4, P2RX5, P2RX6, P2RX7. Any receptor below the white dotted line was considered to be of high abundance in our sample. Figure adapted from Patritti-Cram et al. 2021.

The Big Picture: My research is important because it can help scientists develop therapies for patients that suffer from diseases that impact the nervous system. Currently, over 100,000 Americans suffer from neurofibromatosis type 1 (NF1). Patients with NF1 have an increased risk of developing tumors (neurofibromas) in the peripheral nervous system. Neurofibromas can cause nerve damage and can compress vital organs. They are tumors composed of many types of cells that are not working properly. One type of the cell that plays a very important role in neurofibroma development are Schwann cells. Schwann cells are specialized cells that surround all the nerves in our body. In healthy humans, Schwann cells help to support nerve function. In neurofibroma patients, Schwann cells do not function properly and will multiply uncontrollably. This leads to the development of neurofibroma tumors. To date, there is no cure for this disease. Therefore, the main goal of my research is to understand how these neurofibroma tumors form and develop therapies for patients that suffer from this disease.

In our lab, we use mice to study NF1. We use mice because the genetics of mice closely resemble that of humans. Mice develop neurofibroma tumors in similar places in the body and at a similar rate. In both humans and mice, Schwann cells are at the center of neurofibroma formation. They express many different purinergic receptors and it’s important for scientists to understand the role of these receptors so that we can learn about how Schwann cells function in the body. In our review, we clarify and organize the body of research on this topic. Our research can help scientists understand how purines impact diseases of the nervous system.

Decoding the Language:

Central nervous system (CNS): The CNS consists of two parts, the brain and the spinal cord.

Cycle threshold (CT): The CT is a way to express the abundance of DNA in a sample during an RT-PCR reaction. Each time the DNA is amplified, this can be considered one cycle. If many cycles are required to detect the DNA, then there is a small amount of DNA in the sample. If very few cycles are required to detect the DNA, then there is a large amount of DNA in the sample.

Glial cells: Glial cells are cells in the nervous system that do not produce electrical impulses. They make a fatty substance called the myelin sheath, which wraps around nerve fibers to insulate them and increase the speed at which electrical impulses are conducted. They also provide support and protection for neurons.

Metastasis: Metastasis is the spread of cancer cells from the place where they first formed to another part of the body.

Neurofibroma: A neurofibroma is a type of nerve tumor that forms soft bumps on or under the skin.

Neurofibromatosis type 1 (NF1): Neurofibromatosis type 1 is agenetic disorder that causes tumors, called neurofibromas, to grow in peripheral nerves.

P2X: P2X is a type of purinergic receptor located at the cell membrane that gets activated when a molecule called adenosine 5’-triphosphate (ATP) binds to the receptor. When ATP binds to P2X receptors, molecules that were outside the cell can then move inside the cell. These molecules are sodium, potassium, and calcium and are essential for any cell to function properly.

Peripheral nervous system: The peripheral nervous system is the nerves outside of the brain and the spinal cord.

Purine molecules: Purine molecules are made up of carbon and nitrogen atoms. When the human body produces them, they are called endogenous purines.

Purinergic receptors: Purinergic receptors are a family of molecules or receptors that are found in the cellular membranes of almost all mammalian tissues.

Purinergic signaling: Purinergic signaling is a type of cell signaling that takes place when a purine molecule binds to a receptor embedded in the membrane of a cell. The bound receptor allows other molecules like sodium, potassium, and calcium to enter the cell, triggering a response that allows the cell to communicate with other cells.

Reverse transcription polymerase chain reaction (RT-PCR): RT-PCR is a laboratory technique used to amplify specific DNA targets. To do so, researchers will add a fluorescent tag to DNA and amplify the DNA in a machine. Each time the DNA is amplified, the fluorescent tag glows and the machine records how often the DNA fluoresces. This technique allows scientists to determine how much DNA is in a sample.

Schwann cell: A Schwann cell is a type of glial cell in the peripheral nervous system that helps to form the myelin sheath around nerve fibers. 

Learn More:

Children’s Tumor Foundation article about Neurofibromatosis type 1

New Medical LifeSciences article about Schwann cells

Other research papers from the scientific literature:

Abbracchio, Maria P., et al. “Purinergic signalling in the nervous system: an overview.” Trends in neurosciences 32.1 (2009): 19-29.

Burnstock, Geoffrey. “Purinergic signalling and disorders of the central nervous system.” Nature reviews Drug discovery 7.7 (2008): 575-590.

Burnstock, Geoffrey. “Purinergic signalling: therapeutic developments.” Frontiers in pharmacology 8 (2017): 661.

Synopsis edited by Titilayo Omotade, PhD, Yale University; Yale School of Medicine Office of Diversity, Equity, and Inclusion and Elaine Crutchley, MS, University of Tennessee, Business Analytics and Statistics.

Download this article here

Please take a survey to share your thoughts about the article!

How obesity changes feeding circuits in the brain

Featured Scientist: Mark A. Rossi, Ph.D., Psychiatry Department, Rutgers Robert Wood Johnson Medical School, Child Health Institute of New Jersey.

Mark, a man with a beard, stands on a hill. He is wearing a backpack and there are mountains in the background.
Markhiking in Grand Teton National Park!

Birthplace: Detroit, Michigan.

My Research: I attempt to understand what motivates our behavior and the way that we eat. I focus on how the brain is wired and I am particularly interested in how our diet can rewire our brain circuits.

Research Goals : My goal is to help develop therapies that can treat eating disorders, like diabetes.

Career Goals: I want to push the technological boundaries of how we study the brain.

Hobbies: Soccer! I’ve played all my life.

Favorite Thing About Science: The freedom and flexibility to go where the data takes me.

My Team: I recently opened my own lab, so I am temporarily a team of 1. The lab will soon be populated with research technicians, graduate students, postdoctoral researchers, and undergraduates.

Organism of Study: Mice

An image of a brown mouse on a white background.
Photo by George Shuklin from Wikimedia Commons

Field of Study: Neuroscience

What is Neuroscience: Neuroscience is the study of the nervous system. The goal of this field is to understand how the central nervous system works. The central nervous system includes the brain and the spinal cord. My area of expertise is in how the brain contributes to motivated behavior. Motivated behavior includes any type of behavior that is important for our survival.

Check Out My Original Paper: “Obesity remodels activity and transcriptional state of a lateral hypothalamic brake on feeding”

QR code that links to the original publication
QR code to the original publication

Citation: Rossi MA, Basiri ML, McHenry JA, Kosyk O, Otis JM, van den Munkhof H, Bryois J, Hubel C, Breen G, Guo W, Bulik CM, Sullivan PF & Stuber GD. (2019) Obesity remodels activity and transcriptional state of a lateral hypothalamic brake on feeding. Science. 364(6447):1271-1274.

Research At A Glance: Obesity is an inflammatory condition where our bodies store extra fat. Obesity can increase our chances of developing health issues, such as heart disease. I am mainly interested in understanding the role that our brain plays in obesity. A region of the brain called the hypothalamus is responsible for coordinating many day-to-day actions such as, reproduction, aggression, and feeding. The lateral hypothalamic area (LHA) is an area within the hypothalamus that has neurons that are known to control feeding behavior. A neuron is a brain cell that can communicate with other cells using electrical signals. We don’t know very much about the neurons in the LHA, and it is not clear if they are affected by obesity. In our paper, we characterize the excitatory neurons in the LHA and try to understand how they may be affected by obesity. We used a technique called single-cell sequencing to look at the messenger RNA (mRNA) in a single cell and compare it to other individual cells. This allows us to build a profile of the cells in LHA. In our experiments, we looked at the brain to find differences between lean and obese mice. We found that the pattern of gene expression was different between the mice, particularly within the excitatory neurons. Excitatory neurons are a type of neuron that increase the likelihood that a neuron will create and fire an action potential. In normal conditions, the excitatory neurons will send signals to activate other neurons that function as a ‘brake’ to suppress food intake. We found that a high fat diet can change the activity of excitatory neurons, so they no longer send the signal to suppress food intake. Next, we wanted to see if the cells change in function in response to obesity. We used a technique called longitudinal calcium imaging to magnify and take pictures of the cells under a microscope over the course of 12 weeks. We found that the normal functions of excitatory neurons in the LHA were greatly decreased in obese mice. Our research gives us one mechanism for how the brain may be altered by diet. As we become obese, the excitatory neurons in our brains have reduced activity, which may contribute to the behavior of overeating.

Highlights: One of the goals of our study was to see how the activity of the LHA excitatory neurons change in mice with a high fat diet and how this may contribute to obesity. What we found is that a chronic high fat diet affects how excitatory neurons function,and this can increase overeating. The most important part of this project was our ability to track the activity of individual neurons in the hypothalamus over time (Figure 1). We monitored the mice as they started the high fat diet and as they became obese. This helped us show that while the structure of the individual neurons looked similar in the brain, they did change in function in response to diet over time. That is, single neurons will respond to food rewards but lose that responsiveness as obesity progresses.

A two panel image of neurons inside a mouse brain. They look like bright yellow orbs on a dark blue background. The left panel shows neurons during week 1 and the right panel shows neurons during week 12. The neurons have similar brightness and placement in week 1 and week 12.
Figure 1. An example of the images that we took as we tracked activity of excitatory neurons throughout the course of obesity. The left side shows the neuron cells in the hypothalamus of mice at the beginning of the study. The right side shows the same cells 12 weeks after the same mice were fed with a high fat diet. This technique helps us to look at how the activity of these individual neurons change in response to chronic manipulations such as a high fat diet. So, while the activity of the neurons changed, the cool thing is that the neurons still looked nearly identical to each other! The cells in the picture are labeled with the genetically encoded fluorescent calcium indicator (GECI), GCaMP6. GECI will fluoresce in the presence of calcium, and this allows us to read changes in the activity of a neuron based on how bright it is.

What My Science Looks Like: For this experiment, we fed six mice (n=6) a control diet and seven mice (n=7) a high fat diet for 12 weeks (Figure 2). The high fat diet had higher levels of fat content because it had high levels of sucrose (sugar). Like humans, a diet with a high fat content leads to an increase in body weight for mice. After 12 weeks, mice fed with the high fat diet gain significantly more weight than mice fed on the control diet (Figure 2).

A data figure that shows changes in weight over time. At time zero, mice in both groups were around 25 grams. By week two, mice in the control diet were less than 30 grams and mice on the high fat diet were starting to pass 30 grams. By week 12, mice in the control diet were starting to pass 30 grams, while mice on the high fat diet were nearing 50 grams. The groups were not significantly different until week 12.
Figure 2. The weight of mice on a high fat diet changes over time. The y-axis shows the weight of the mice, and the x-axis shows the time it took for the mice to become obese. The star (*) denotes the results of our statistical test. It shows that the mice on a high fat diet had a body weight that was significantly different than the body weight of the mice on the control diet in week 12. Figure adapted by al.2019

The Big Picture: Obesity is a serious medical problem that is widespread in the United States. It is associated with increased risk of death from heart disease, stroke, and diabetes. While it affects many people, there are few viable treatment options. It is important to understand how the brain controls normal eating and overeating. This knowledge is critical to help us develop new treatments for eating disorders and obesity. Our research tries to understand how the brain contributes to normal feeding. It also looks at how those same brain circuits are affected by an unhealthy diet. Measuring the activity of neurons in the hypothalamus using multiple methods can help us get a more complete picture of the ways that the brain controls feeding behavior. Our research provides us with important insights and a deeper understanding of how the brain can be changed by obesity.

Decoding the language:

Action potential: Action potentials are electrical signals that allow information to be transferred to the nervous system. The nervous system will then transmit information to its target cells.

Brain circuits: Brain circuits consist of a web of neurons that are connected to each other. Information will flow from one neuron to another to send information to other parts of the brain. This is similar to the electrical circuits in our homes. When you walk into a room and flip a light switch, the electrical current will be carried across the room to turn on a light bulb.

Neuron: A neuron is a cell that acts as messenger. It sends and receives information to and from the brain and spinal cord. This information then goes to different areas of the body. For example, when you are hungry your stomach will send a signal to a region in your brain called the hypothalamus to let you know that you need food!   

Excitatory neurons: Excitatory neurons are cells in the brain that increase the likelihood that a neuron will create and fire an action potential. When neurons fire an action potential, they are using electrical signals to communicate to other cells. The excitatory neurons are distinct from other types of neurons, like inhibitory neurons, because they increase the signal, rather than silencing it.

Gene expression: Gene expression allows us to measure gene activity. At any given time, our bodies will turn on genes to perform important bodily functions. For example, if you are eating a sandwich, your body may turn on a gene that codes for an enzyme to help break down the food in your mouth. Before a gene can perform a function, it must be converted into messenger RNA (mRNA). Therefore, we can measure the expression of a specific gene by quantifying how much mRNA for that gene is in a sample. We say that a gene has high expression when the mRNA for that gene is very abundant in our sample. In our study, we changed the diets of our mice and measured which genes had high expression after the change in diet. This helps us to understand the role of certain genes in conditions like obesity.

Genetically encoded fluorescent calcium indicator (GECI): GECI is a tool that marks a set of neuron cells by binding to calcium ions. This allows us to track the calcium activity which is associated with the firing of action potentials. Higher calcium activity will manifest as a brighter signal, with the help of a fluorescent dye. It allows us to read the activity of the neurons to better understand how neuronal activity relates to behavior.

Hypothalamus: The hypothalamusis an area in the brain that plays an essential role in regulating motivated behaviors. This can include hunger, reward responses, and homeostasis. The hypothalamushelps to keep the body stable and plays a role in heart rate and blood pressure.

Lateral Hypothalamus area (LHA): The LHA is a small region in the hypothalamus that regulates feeding behavior. In this research, we looked at cells in the LHA to see how these cells were affected by obesity.

Messenger RNA (mRNA): mRNA are intermediate molecules between DNA and proteins. In our research, we used mRNA to look at patterns of gene expression. This allowed us to identify which genes were being activated in the LHA neurons in response to our control and high fat diet.

Single-cell sequencing: Single cell sequencingis a specific form of gene sequencing. Gene sequencing allows us to read the genetic code in DNA and quantify how much of each gene is present in a sample. Most gene sequencing techniques read the genetic code of several cells at one time. The single cell sequencing method is unique because it allows us to measure gene expression in individual cells. This method allowed us to target excitatory neurons and see how diet impacts gene expression in these specific cells.

Learn More:

Video on how neurons communicate

More research papers about how the circuits in the brain contribute to feeding behavior:

Rossi MA & Stuber GD (2018) Overlapping brain circuits for homeostatic and hedonic feeding. Cell Metabolism, 27(1): 42-56.

Rossi MA, Marcus L. Basiri, Yuejia Liu, …, Charu Ramakrishnan, Karl Deisseroth, and Garret D. Stuber (2021). Transcriptional and functional divergence in lateral hypothalamic glutamate neurons projecting to the lateral habenula and ventral tegmental area. Neuron, 109, 1-15.

Synopsis edited by Maisam Yousef, B.S. 2019, Illinois State University, and Naiomy Rios Arce, PhD.

Download this article here

Please take a survey to share your thoughts about the article!

Graduate Student Experiences of Sexual Violence and Sexual Harassment (SVSH)

Featured Scientist: Cierra Raine Sorin (she/her/hers), Ph.D. Candidate (Anticipated: Spring 2022), Department of Sociology with a Doctoral Emphasis in the Department of Feminist Studies, University of California Santa Barbara

Pale feminine person with long, wavy purple hair, wearing purple lipstick at an office desk with a fake plant in the background.
Cierra working in her campus office, pre-pandemic!

Birthplace: Loma Linda, California

My Research: My research is intersectional, meaning that I study people’s identities and how those identities impact their lives. I am interested in how having different identities impacts people’s ability to give consent and to have that consent recognized by others. Using qualitative methods, I study how people understand and react to sexual violence and sexual harassment (SVSH) in their communities, and in the institutions that they belong to. Some of my research questions include:

  • How do people understand and give consent?
  • How are people’s individual understanding of consent connected to group norms, such as normal group beliefs that revolve around sexual behavior?
  • How do these group norms make sexual violence acceptable, so it keeps happening?
  • What do people do when they have experienced sexual violence in their community or institution, like the workplace or in school?

Research Goals: My research focuses on sexual consent. I want to know how consent violations happen in institutional settings and what we need to know about these settings to protect people’s consent. For example, sexual harassment is one type of sexual violence that is common in workplaces, even though it is illegal. My goal is to understand how and why people experience discrimination in the institutional settings that are supposed to help and protect them.

Career Goals: My work has always revolved around solving social problems. While I love being in academia, it is very important to me to do work that benefits society. I see myself in a professor position where I can pursue research and teaching to improve the world around me. Another dream of mine is to write social justice-oriented children’s books, with my partner as the illustrator!

Hobbies: My hobbies include spoiling my German Shepherd pup, Lilith, swimming and doing yoga, watching bad crime television shows, like CSI, and playing action RPG video games with my partner!

Favorite Thing About Science: I love that in science, there really is something for everyone. Anyone with curiosity and interest in how the world around us works can become a scientist! As a social scientist, I study people and how they interact and co-exist. This may seem very different from someone who studies atoms, oil spills, or butterfly migration patterns, but there are many similarities in that the end goal is to gain a better understanding of how to make the world a better place.

My Team: This paper is the result of an amazing collaboration with several other researchers from a larger team project called UC Speaks Up, which took place across three University of California campuses: UC Santa Barbara (UCSB), UC San Diego (UCSD), and UC Los Angeles (UCLA). Our team of faculty members, graduate students, undergraduate students, and research staff collectively designed and carried out multiple kinds of qualitative data collection. Here, I discuss the data we collected from graduate students participating in focus group discussions (FGDs) and in-depth interviews (IDIs). As a graduate student intern on the project, I oversaw the UCSB undergraduate student researchers and acted as a liaison with the larger team based at UCSD. I also conducted all of the IDIs with UCSB graduate students and led both of the FGDs. During this time, I became good friends with another graduate student intern, Brittnie Bloom. Having similar research interests, we decided we wanted to analyze the experiences of graduate students in our data set. Working with our research advisors, Dr. Laury Oaks (UCSB) and Dr. Jennifer Wagman (UCLA), we have written three papers that speak to the different experiences graduate students have with SVSH and campus resources. In this paper, I took on the role of second author and Brittnie took the role as the first author. While Brittnie led the writing process, the formatting, and the submission, we worked closely together to make decisions, analyze the data, and write the paper.

Field of Study: Sociology

What is Sociology? Sociology is the study of social life and human behavior. We are interested in the relationship between individuals and the social environments they exist in. This includes their groups, institutions, and societies more broadly. Sociologists study a variety of social issues, and many connect to forms of inequality.

Check Out My Original Paper: “Employees, Advisees, and Emerging Scholars: A Qualitative Analysis of Graduate Students’ Roles and Experiences of Sexual Violence and Sexual Harassment on College Campuses”

Citation: Brittnie Bloom, Cierra Raine Sorin, Jennifer Wagman, and Laury Oaks. 2021. “Employees, Advisees, and Emerging Scholars: A Qualitative Analysis of Graduate Students’ Roles and Sexual Violence and Sexual Harassment on College Campuses.” Sexuality and Culture, (doi: 10.1007/s12119-021-09841-w).

Research At A Glance: It is very important to understand SVSH experiences among graduate students. SVSH includes, but is not limited to, stalking, sexual harassment, and invasion of sexual privacy. SVSH is common on college and university campuses but research in this area rarely focuses on graduate students. This is an important gap in campus SVSH studies because graduate students take on many roles for the university. They engage in teaching and mentoring students and in conducting research with faculty. In many of these roles, graduate students face unequal power roles that can make them vulnerable to sexual violence. We wanted to better understand the experiences of SVSH of graduate students on all three University of California (UC) campuses: UC Santa Barbara (UCSB), UC San Diego (UCSD), and UC Los Angeles (UCLA). To do so, we conducted 21 IDIs and 8 FGDs with a diverse group of 43 graduate students, between 23 and 34 years of age. The study consisted of Masters students, PhDW students, and professional students. Participants were mostly heterosexual and 32% identified as LGBTQ+. Of our UC graduate student participants, 41% identified as white, 25% as Asian, 16% as Hispanic/Latino, 6% as Black and 10% as more than one race or ethnicity.  Our research was part of a larger study, but our focus was on the experiences of graduate students. Some of our questions included student knowledge of and perception of SVSH. Additionally, we asked graduate students their opinions about SVSH prevention and the role that they play in reporting and responding to sexual violence. We wanted to see how graduate students understand SVSH, how they work in an environment where they may be faced with unequal power roles, and how to prevent SVSH. We also wanted to raise awareness to situations where these students may be vulnerable or more likely to experience sexual violence.

Highlights: SVSH is a continuing problem on college and university campuses. Students in disciplines that historically lack diverse faculty are at a higher risk of SVSH. Until recently, most research on SVSH has focused on students that identify as white. These studies have also not been intersectional, where students have more than one identity. Our study highlights the importance of race and ethnicity in SVSH work. The stories that we heard from students emphasize that SVSH work is also diversity work. SVSH needs to be more culturally informed because students from underrepresented backgrounds are more likely to experience SVSH. The same is true for sexual orientation. People who identify as gay or lesbian are more likely to experience SVSH than those who identify as heterosexual. Transgender individuals and bisexual individuals are the most likely to experience sexual violence. The students who participated in our study were able to share unique experiences that spoke to these issues. One Latinx student spoke about some of her cultural norms which involve greeting people by kissing. She explained that she was uncomfortable when Latinx faculty engaged in that behavior in academic settings but wasn’t sure about how to respond when it took place. Understanding that certain behaviors have a cultural context is important for teaching and learning consent. We need to recognize and respect the unique experiences of all people in our academic communities and support survivors to prevent SVSH.

What My Science Looks Like: In our study, we identified three themes, detailed below.

  1. Graduate students do not trust university reporting and aid processes because they feel that reporting SVSH can negatively impact them.
  2. Graduate students don’t know about the rates of SVSH on campus or if they are at risk of experiencing SVSH.
  3. Graduate students remain silent about SVSH because of power hierarchies that exist among faculty members, such as professors or mentors.
Themes identified in our study of SVSH experiences among UC graduate students

The Big Picture: Most people who complete a graduate degree are in school for many years. Depending on the environment, graduate students might experience abuse of power by faculty. This can make them more vulnerable to sexual violence. Reporting violence can also have a negative impact on students. Some students experience bullying or lawsuits. Many don’t feel safe reporting their experiences because they may not stay anonymous. It’s a huge risk. Some graduate students have such bad experiences that they choose to or are forced to leave academia altogether. No one should be forced to make the decision between their personal safety and their career. Universities are trying to prevent and respond to sexual violence. One way has been to change group norms about sexuality and consent. However, most of these efforts overlook graduate students. This is a problem because graduate students and undergraduate students have different roles at the university. Interventions that work for undergraduate students may not work well for graduate students. Universities can better support graduate student populations by listening to their experiences. In our paper, we present ideas and solutions that can make the university a safer place for everyone. We suggest recruiting people from different backgrounds to participate in making SVSH policies. We also suggest holding university leaders accountable for any policies, procedures, or practices that protect perpetrators and harm survivors. This includes calling out bad behavior and making sure that faculty engaging in inappropriate behavior are removed from their positions.

Decoding the Language:

Culturally informed: Culturally informed practices are those that recognize that we all belong to different cultures with potentially different group norms and take that into consideration when developing prevention and response efforts. Accounting for these differences is important in reaching most people effectively.

Diversity work: Diversity work refers to the efforts made in an institution or organization to make the environment and group norms more supportive of people from a diverse set of backgrounds.

Group norms: Group norms are the rules for behavior in a particular group. For example, this can be the way you are expected to dress, how you speak, when and what you eat, and so on.

Institutions: Institutions are formal social structures that include governments, universities, churches, and workplaces. They exist beyond the individuals that take part in them but provide group norms and expectations for how people should live and behave.

Intersectional: Doing intersectional work means examining the different social and political identities that people occupy to understand how they experience privilege and/or discrimination. Common categories of intersectional analysis include race and/or ethnicity, gender, dis/ability, social class, and age, but there are many others!

Qualitative methods: Qualitative methods are types of research methods. Information is collected through observations or through interviews. In our study, we used in-depth interviews (IDIs), where we talked with graduate students one-on-one, and focus group discussions (FGDs) where we did group-style interviews with multiple graduate students at the same time.

Sexual violence and sexual harassment (SVSH):  Sexual violence and harassment is any activity, attempted or completed, where one (or more) person uses violence, coercion, force, or drugs to control another to engage in a sexualized activity. Sexual violence is usually not about sex itself, but about someone using power to harm someone else. Sexual violence includes incest, rape, sexual assault, stalking, sexual harassment, and more.

Learn More:

To learn more about the UC Speaks Up project, including some of the other efforts of the group and its members, you can check out our website!

To learn more about intersectionality, I recommend this short Vox interview of Professor Kimberlé Crenshaw, thirty years after she coined the term.

Synopsis edited by Maisam Yousef, B.S. 2019, Illinois State University, and Titilayo Omotade, PhD, Yale University, Yale School of Medicine.

Download this article here

Please take a survey to share your thoughts about the article!

What’s killing the buzz? Investigating the multiple stressor hypothesis for bumble bee health

Featured Scientist: Austin C. Calhoun, M.S. (he/him/his), PhD student (Anticipated: Spring 2025), School of Biological Sciences, Illinois State University

Austin posing on tree stumps at a riverbed.
“Act like a bluebell and the bees will come.” – Austin Calhoun

Birthplace: Danville, IL, USA

My Research: I am interested in how bumble bees defend against parasites and pathogens.

Research Goals: I would like to continue to study disease. I am interested in how diseases arise, how individuals can defend against them, and what environmental contexts amplify the effects of disease. I would also like to study methods that can be used to predict the occurrence of disease in the future.

Career Goals: Ideally, I see myself as a professor at a university, where I could continue to conduct research and to teach. Then, maybe I’ll retire after running a field research station somewhere.

Hobbies: Cooking on a cast iron, building things out of wood, and getting deep into YouTube holes about jiu-jitsu.

Favorite Thing About Science: My favorite thing is the freedom of creativity. Being interested in some question about nature, designing a project to answer that question, and then telling the world about something new.

Organism of Study: The common eastern bumble bee and its pathogen, Nosema bombi (N. bombi).

A close-up picture of a bee on a brood of developing juveniles and a microscope image of N. bombi.
Bumble Bee (left) and N. bombi (right). Photos by Dr. Benjamin Sadd, Illinois State University

Field of Study: Disease Ecology

What is Disease Ecology? Disease Ecology is the study of how organisms interact with their pathogens. A pathogen is a disease-carrying microorganism, like a bacterium or a virus. When an organism is infected with a pathogen, it becomes a host for that pathogen. People who work in disease ecology also study other factors that affect how the host and the pathogen interact. For example, a disease ecologist might study the environment, pesticides, or climate change and how they impact the host or the pathogen.

Check Out My Original Paper: “Testing the multiple stressor hypothesis: chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health”

 A QR code that links to the original publication.
QR code to the original publication

Citation: Calhoun A.C., Harrod A.E., Bassingthwaite T.A., Sadd B.M. 2021 Testing the multiple stressor hypothesis: chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health. Proc. R. Soc. B 288: 20202922. (doi: 10.1098/rspb.2020.2922)

Research At A Glance: Bees serve important roles as pollinators, but they deal with many stressors that can negatively affect their health. Climate change, habitat loss, pesticide exposure, and pathogens are types of stressors that can negatively impact bee populations. Although each of these are individually harmful, bees likely experience more than one at a time. When bees are exposed to multiple stressors at once, they may experience worse outcomes. We call this concept the multiple stressor hypothesis. In this research, we test the multiple stressor hypothesis using a species of bumble bee, Bombus impatiens (B. impatiens).

Several species of bumble bee are in decline across North America. One possible reason could be a pathogen called Nosema bombi (N. bombi). N. bombi is a stressor found in many of the bumble bee species that are experiencing population declines. After infecting the bee, it will produce a spore as part of its reproductive cycle. The spores have a hard outer layer that makes them environmentally resistant and these N. bombi spores can infect bees. At the same time, many bumble bees are also exposed to a fungicide called chlorothalonil. A fungicide is a special type of pesticide used to kill fungal pathogens. In 2017, a study found a relationship between the use of chlorothalonil, the presence of N. bombi, and declining bee populations. We wanted to explore this relationship further.

To do this, we infected bumble bees with N. bombi and exposed them to chlorothalonil. Our goal was to test how the combination of these stressors might impact bumble bee health. We measured health by looking at how long the bees survived, how big they were, and how much protein was in their bodies. To make sure that exposure to N. bombi resulted in infection, we calculated how much N. bombi DNA was in each bee as a measure of total infection intensity. We also counted the number of N. bombi spores present in the gut of each bee as a separate measure of infection. We found that chlorothalonil exposure did not increase the total infection intensity or worsen bumble bee health. But we did find that bees exposed to chlorothalonil had more N. bombi spores in their bodies. This meant that bees infected with N. bombi had a higher potential to transmit the environmentally resistant form of the pathogen to other bees. In this research, we did not find solid support for the multiple stressor hypothesis because the bees did not have worse health outcomes when exposed to both N. bombi and chlorothalonil. Instead, we found that chlorothalonil exposure enhances the potential for N. bombi to transmit to new bees.

Highlights: In this research, we exposed bumble bee larvae to chlorothalonil, N. bombi, or both. Larvae are immature bees. Nosema only infects bees during the larval stage of development, which is why we infected them at this stage. We kept the larvae in the lab and allowed nursing bees to take care of them until they grew into adults. At that point, we measured bee health, quantified total infection intensity for each bee, and counted the number of N. bombi spores each bee had. To quantify total infection intensity, we used a technique called quantitative polymerase chain reaction (qPCR). qPCR is a molecular technique that allows a researcher to count how much DNA is in a sample. We used this technique to measure how much N. bombi DNA was inside adult bees that had been exposed to chlorothalonil as larvae and in those that had not been exposed to chlorothalonil. Figure 1 shows the results of this test. The dots in Figure 1 show the average N. bombi infection for bees exposed to chlorothalonil and for those not exposed to chlorothalonil. The “ns” above the dots in Figure 1 show the results of the statistical test that we did to see if the total infection intensity was different between the two groups. Here, “ns” stands for “not significant.” This indicates that the average infection was not significantly different when bees were exposed to both chlorothalonil and N. bombi.

A graph that shows total infection intensity data from two groups of bees, those that were exposed to chlorothalonil as larvae and those that were not. There is no significant difference in total infection intensity between the two groups.
Figure 1. The effect of the chlorothalonil treatment on the total N. bombi infection intensity in adult bees. The y-axis shows the relative amount of N. bombi DNA measured in the bees using qPCR. The x-axis shows whether bees were exposed to the chlorothalonil treatment as larvae.

To count the number of N. bombi spores each bee had, we euthanized each bee, pulverized their abdomens, looked at it under a microscope (see the N. bombi picture in the “Organism of Study” section), and recorded the number of spores present in each bee. We did this because the number of N. bombi spores inside each bee should tell us how ready the pathogen is to transmit to a new host. Figure 2 shows the results of this test. The dots in Figure 2 show the average number of N. bombi spores in bees exposed to chlorothalonil and in those not exposed to chlorothalonil. The two stars (**) above the dots in Figure 2 show the results of the statistical test that we did to see if the number of N. bombi spores was different between the two groups. The stars indicate that there was a significant difference between the two groups. These results show that bees exposed to both N. bombi and chlorothalonil as larvae had significantly more spores per bee when compared to bees that were not exposed to chlorothalonil. This is important because bees that have more spores are more likely to transmit N. bombi pathogens to other bees.

A graph depicts data from counting the number of N. bombi spores in bees exposed to chlorothalonil and those not exposed to chlorothalonil. Bees exposed to chlorothalonil had more N. bombi spores in their abdomens.
Figure 2. The effect of the chlorothalonil treatment on the number of N. bombi spores. The y-axis shows how many N. bombi spores were in each bee. The x-axis shows whether bees were “exposed” to the chlorothalonil treatment as larvae.

What My Science Looks Like: To conduct this experiment, we needed to infect bumble bees with N. bombi. The image below shows the exact method of delivery. N. bombi can only infect bees when they are larvae, so each larva had to be hand-fed the spores. We did this by peeling open the wax casing that protects the larvae and placing food infected with spores at the mouth of each larva. After feeding, they were returned to their homes, the nursing bees would re-seal the wax, and the bees would continue to develop. Nursing bees were bees randomly selected from the colonies to raise the larvae. They are used to maintain the brood until adulthood.

A picture of bumble bee larvae being hand-fed N. bombi spores with a pipette.
B. impatiens larvae receiving a dose of N. bombi spores.

The Big Picture: Bumble bees are especially valuable insects. They increase agricultural production and provide many services that improve ecosystem health. However, some species of bumble bees are in decline. To help them, we must understand how known stressors such as pathogens may impact their health. In our research, we found that a commonly used fungicide may increase the potential for a pathogen to be transmitted to other bees. One possible explanation for our results is that the fungicide chlorothalonil makes the current host less suitable for the pathogen. In response, N. bombi produces more spores to transmit to a new, more suitable host. While higher spore production was the only negative effect that we found related to chlorothalonil, it is important to keep in mind that we only used one bee species, B. impatiens. B. impatiens populations are stable in nature, so it is possible that other bumble bees are more sensitive to the dual effects of chlorothalonil and N. bombi. Regardless, researchers should continue to look at multiple stressors and how they impact bee health. Our research is important because if we can identify factors that increase pathogen transmission or virulence, we can make predictions about how future diseases may impact bee populations. This type of research helps us to understand patterns of disease, prevent outbreaks, and preserve important native pollinators.

Decoding the Language:

Bombus impatiens (B. impatiens): B. impatiens is the scientific name for the common eastern bumble bee.

Chlorothalonil: Chlorothalonil is a type of fungicide that is often sprayed onto crops and used in household gardens. When bees pollinate a plant that has been treated with this type of fungicide, it is easy for bees to pick up chlorothalonil and bring it back to the colony because it stays on the surface of the plant.

Fungicide: A fungicide is a pesticide used to kill fungal pathogens. They are generally used to protect crops from pathogens that may hinder crop development.

Host: A host is the organism infected by a pathogen. The pathogen will extract energy from the host.

Larvae (plural), larva (singular): A larva is the immature stage of an insect’s life, well before it reaches adulthood. The stages of growth go from egg to larva, to pupa, then to adulthood.     

Multiple stressor hypothesis: The multiple stressor hypothesis is the concept that exposure to many stressors will have a more negative impact on the organism than exposure to one alone.

Nosema bombi (N. bombi): N. bombi is the scientific name for the pathogen used in this study, which is known to harm bumble bees.

Nursing bees: A nursing bee is one type of worker bee in a colony. The nursing bees are responsible for taking care of the developing larvae. In the context of this study, our nursing bees were those that were picked to raise the larvae used in our research.  

Pathogen: A pathogen is a disease-causing microorganism, like a bacterium or a parasite.               

Quantitative polymerase chain reaction (qPCR): qPCR is a molecular technique that is used to quantify the amount of DNA within a sample. In this process, the DNA of interest has a fluorescent tag added to it and the DNA is amplified inside a machine. The fluorescent tag glows each time a new DNA strand is made, and the machine counts how many times the DNA glows.

Spores: In the context of this study, a spore is the environmentally resistant stage of Nosema bombi. The spores have a tough, thick outer coating, which allows them to be environmentally resistant.

Stressor: A stressor is any identifiable factor that can negatively affect an individual’s health.

Total infection intensity: Total infection intensity refers to our measure of how infected the adult bees were, after they had been exposed to N. bombi as larvae. We quantified the intensity of infection using qPCR.

Virulence: Virulence refers to theharmfulness of a disease. If it is more virulent, it is more harmful.

Learn More:

A book on how to create good pollinator habitat

Information from the United States Department of Agriculture (USDA) on how to gardeners can help pollinators

Synopsis edited by Emily Kerns (she/her/hers), PhD student as of September 2021, University of Wisconsin-Madison, Integrative Biology, and Maisam Yousef, B.S. 2019, Illinois State University.

Download this article here

Please take a survey to share your thoughts about the article!

Fruit flies shed light on how immune responses are regulated

Featured Scientist: Pooja Kadaba Ranganath (she/her/hers), PhD (Anticipated: January 2022), School of Biological Sciences, Illinois State University

Two pictures of Pooja KR. In one, she stands in front of the river holding a cup of coffee. In the other, she stands in a museum next to an image of a human body.
Pooja enjoying hot chocolate from Ghirardelli near the Chicago River (left) and exploring a science museum in Washington D.C (right).

Birthplace:  Bangalore, India

My Research: In my research, I work to understand how the immune system works and how it defends itself against germs that can cause sickness, also called pathogens.

Research Goals: I want to work at the intersection of two types of science, basic and translational. The goal of basic research is to learn how a particular system works. The goal of translational research is to apply the information that we learn from basic research to help humans. My main interest is to do research to understand cancer and help make personalized medicine a reality for patients.

Career Goals: I want to help advance medicine by working in the industry research setting.

Hobbies: In my free time, I like to cook, spend time with friends and family, try out new food, and practice a classical form of Indian music. I also love to travel and explore new places.

Favorite Thing About Science: Cells are amazing to me. It is fascinating to explore the mysteries of the body and use that information to support human health. Science allows you to explore new questions. I love the feeling that my work can make a difference to people who are in need.

My Team: The research for this paper was made possible with the help of Jonathan Lee, an undergraduate student who helped me do the experiments, and the principal investigator, who supervised us throughout the process.

Organism of Study: The fruit fly, also called Drosophila melanogaster.

A picture of a fruit fly. It had red eyes and a light brown body.
Image source: Wikimedia Commons

Field of Study: Cellular Immunology

What is Cellular Immunology? Cellular Immunology is a type of biology. When a person is infected with a pathogen, the immune system is activated to destroy the pathogen before the person can get sick. Researchers in the field of cellular immunology will study the cells and molecules of the immune system to understand how they all work together to protect the body.   

Check Out My Original Paper: “The S1A protease family members CG10764 and CG4793 regulate cellular immunity in Drosophila”

QR code to the original publication

Citation: KR, P, Lee, J, Mortimer, NT. 2021. The S1A protease family members CG10764 and CG4793 regulate cellular immunity in Drosophila. micropublication Biology. (Doi: 10.17912/micropub.biology.000370)

Article written by Rosario Marroquin-Flores, PhD (Anticipated: August 2022), Illinois State University

Research At A Glance: The immune system plays an important role in protecting our bodies against pathogens. When exposed to a pathogen, the body will turn on immune cells to help defend the body against infection. This is called the immune response. To understand how the human immune system functions, scientists often study the immune systems of other animals. In our research, we used the fruit fly and a parasitic wasp to learn more about the immune response. In nature, parasitic wasps can infect flies by laying their eggs inside the body of the fly. When the wasp infects the fly with its eggs, the immune system of the fly will activate to kill the parasite. Special immune cells in the fly recognize the infection, bind to the wasp egg, and surround it with several layers of proteins in a process called encapsulation. During encapsulation, immune cells surround the egg and harden to stop the wasp from getting vital nutrients, killing the parasite. In our research, we identified two important genes called CG10764 and CG4793 that may impact the fly immune response. To figure out what these genes do, we turned them off and measured how the absence of these genes impacted the encapsulation process. We found that these two genes have opposite roles. One gene is involved in turning on the immune response, while the other is involved in turning off the immune response.

Highlights: One important cell involved in the fly immune response is called a lamellocyte. Lamellocytes are immune cells that turn on in response to infection and help form the capsule that kills the wasp parasite. In this study, we turned off our two genes of interest, CG10764 and CG4793, in lamellocyte cells.Then, we watched to see if the fly was still able to encapsulate the wasp egg. Figure 1 is a boxplot that shows how encapsulation changed when our genes of interest were turned off. 

A data figure that shows the percent of encapsulated wasp eggs when CG10764 and CG4793 are turned off. In unchanged cells, around 50% of eggs are encapsulated. When CG10764 is turned off, around 25% of eggs are encapsulated. When CG4793 is turned off, around 80% of eggs are encapsulated.
Figure 1. The percent of encapsulated wasp eggs when CG10764 and CG4793 are turned off in lamellocyte immune cells. The y-axis (vertical) shows the percentage of eggs that were encapsulated. The x-axis (horizontal) shows which gene was absent. Figure adapted from KR et al. 2021.

The letters in Figure 1 show the results of the statistical test. When the letters are different, that means that the percentage of wasp eggs encapsulated by the fly changed. We see that the percentage of eggs encapsulated went down when CG10764 was removed from the cell, compared to unchanged cells. We can see this because the boxplot for “CG10764 gene absent” has a “B” above it while the boxplot for cell unchanged has an “A” above it. We see the opposite effect for CG4793. We see that the percentage of eggs encapsulated went up when CG4793 was removed from the cells because the boxplot for “CG479 gene absent” has a “C” above it while the boxplot for cell unchanged has an “A” above it.

These results suggest that CG10764 may activate the fly immune response to help it fight against the infection. When CG10764 is absent, the fly has a harder time encapsulating the wasp eggs. Our results also suggest that CG4793 can turn off the fly immune response. When CG4793 is absent, the fly is better at encapsulating wasp eggs. We think that these two genes work together to help regulate the immune system when the fly is infected. CG10764 turns on the response and CG4793 turns it off.

What My Science Looks Like: In our research, we work with fly larvae, these are immature flies that have not yet grown their wings. We allow the parasitic wasps to lay their eggs inside the body of the larvae. It usually takes 72 hours for the fly to encapsulate the wasp eggs.  The image below shows a fly larva with an encapsulated wasp egg inside it.

A picture of an infected fly larva under a microscope. The larva looks fat and grub-like. The encapsulated wasp eggs look like hard black ovals.

Microscopic image of a fly larvae infected with a wasp egg. This fly has successfully encapsulated the wasp parasite. Image adapted from Mortimer et al. 2012.

Recall that lamellocyte cells are immune cells that help form the capsule that kills the wasp parasite. The image below shows what a lamellocyte looks like under the microscope. 

A picture of a lamellocyte cell under a microscope. The cell looks amoeba-like and gelatinous.
Microscopic image of a fly lamellocyte cell.

The Big Picture: In this study, we start to get a better understanding about how the fly immune response is regulated. The fruit fly is a model organism, which means that it has been very well studied and there are many tools available to understand the genes of the fly. Model organisms are often used to study human diseases and several parts of the immune response in the fruit fly can be applied to humans. In our research, we have identified two genes that may help regulate the immune response and this might help us to understand human immune systems too.

 Decoding the Language:

Basic research: Basic research is a type of research with the goal of understanding a particular phenomenon or law of nature. The goal of basic research is to advance knowledge in a particular topic.

Boxplot: A boxplot is a graph that shows you information about the spread of your data. The top line of the box shows the 75th percentile. This is where 75% of the data fall below the line, and 25% of the data fall above the line. The line in the middle of the box shows the 50th percentile, or the middle of the data. The bottom line shows the 25th percentile. This is where 25% of the data fall below the line and 75% of the data fall above the line. The lines that extend from the box in either direction are called whiskers. They show the range of the highest values and the lowest values of the data set.

Encapsulation: Encapsulation is the process of enclosing something. In the context of this research, it is the process of surrounding the wasp egg with layers of protein that harden around the parasite to kill it.

Gene: A gene is a unit of heredity passed from parents to offspring. Genes normally code for proteins that have certain functions in the body.

Immune response: An immune response is the reaction that the body has when it encounters a pathogen. The purpose of this response is to defend the body. In the context of this research, the immune response of the fly is to activate the immune cells that the fly needs to encapsulate the wasp egg.

Lamellocyte: A lamellocyte one of several types of immune cell that is turned on when the body identifies an infection, and these cells play a role in the encapsulation process in flies.

Larvae (plural): A larva (singular) is the immature form of an insect. Larvae often look very different from the adult form of the insect. As the larvae grow, they will change to look more like the adult version of the insect.

Model organism: A model organism is a non-human species that is very well studied and is used to learn more about other species. Model species are frequently used to study human disease.

Pathogen: A pathogen is a bacteria, virus, or other microorganism that can cause disease.

Principal investigator: A principal investigator is the person responsible for organizing and managing a research project or lab. In colleges, faculty often serve as principal investigators and run research labs with graduate and undergraduate students.

Translational research: Translational research is a type of applied research with the goal of improving human health.

Learn More:

University of Arkansas Medical Sciences (AKMS) information on translation research

National Institutes of Health (NIH) information on model organisms

Dros4schools information on the fruit fly as a model organism

A video of a wasp laying eggs inside a fly larva

Article edited by Brooke Proffitt, B.S. in Zoology, University of Illinois-Alumni.

Download this article here

Please take a survey to share your thoughts about the article!

How different are bird parasite communities between mountain ranges?

Featured Scientist: Dr. Lisa Barrow (she/her/hers), Assistant Professor and Curator, Museum of Southwestern Biology and Department of Biology, University of New Mexico.

A large green Luna Moth perched on the side of Lisa's head while in the forests in the Southeastern United States. She was a graduate student at the time and was hiking through the woods, probably looking for amphibians.
Making friends with a Luna Moth while exploring the Southeastern United States during my Ph.D. fieldwork.

Birthplace:  Tempe, Arizona, USA

My Research: I am interested in understanding the diversityof amphibians and reptiles. I study how species have evolved over time, where they occur, and what leads to the loss of diversity in these species.

Research Goals: My research uses information from museum collections to study how different species change over time. A museum collection is almost like a library, but instead of books, it contains the preserved bones, furs, feathers, and tissues of animals from across the world and throughout time. Part of my work is to make sure that we continue to build our museum collections so that other researchers can use them to ask their own questions. My research moving forward will focus on herpetofauna, or “herps” for short. These are amphibians and reptiles. I have also enjoyed studying birds and mammals in my previous work.

Career Goals: I recently started as an Assistant Professor and Curator of a museum collection – this has been my career goal for a very long time! I now look forward to continuing my research and training students to help them pursue their goals.

Hobbies: I enjoy traveling to new places to see new herps and birds, learn about other cultures, and try different cuisines. I also enjoy baking and trying new recipes at home.

Favorite Thing About Science: Learning never ends! I especially love that science is a team effort, and we can always keep learning from other people with different knowledge and expertise than we each have on our own.

My Team: This project was a huge team effort. At the time of this project (2016-2018), I was a postdoctoral researcher working in Dr. Chris Witt’s lab at the University of New Mexico. We led a team that included three undergraduates, four post-bacs, four graduate students, and four lab associates and former students. Together, we conducted the first community-wide survey of bird blood parasites in New Mexico. I helped with fieldwork, sample collection, specimen preparation, and trained the students who conducted molecular work, the microscopic examination of blood cells, and data analysis. I drafted the manuscript with great input from Dr. Chris Witt and the other co-authors. From the time we finished data collection, it took another few years to finish analyzing and writing!

Organism of Study: Birds and their haemosporidian parasites, including many different lineages in the groups Plasmodium, Parahaemoproteus, and Leucocytozoon.

A three panel image. The top image shows a vireo, a small grey bird on a log. The bottom two images show parasites inside bird blood cells. The Leucocytozoon parasite is larger, more circular, and causes the infected blood cell and its nucleus to change shape. The Parahaemoproteus parasite is wrapped around the nucleus of the blood cell. Both parasites are stained a light purple color and the nuclei of the bird host cells are dark purple.
The vireo (scientific name: Vireo plumbeus) seen in the top image is an example of a bird species sampled in our study. The bottom images show examples of their common haemosporidian parasites, Leucocytozoon and Parahaemoproteus. The arrows point to infected blood cells. Image source: WikiMedia Commons

Field of Study: Community Ecology

What is Community Ecology? Community ecology is the study of groups of species and how they interact with one another. People who study community ecology look at how species compete with each other, how they are organized in space, and how they live together.

Check Out My Original Paper: “Detecting turnover among complex communities using null models: a case study with sky‐island haemosporidian parasites”

A QR code that links to the original publication.
QR code to the original publication

Citation: Barrow, L.N., Bauernfeind, S.M., Cruz, P.A., Williamson, J.L., Wiley, D.L., Ford, J.E., Baumann, M.J., Brady, S.S., Chavez, A.N., Gadek, C.R., Galen, S.C., Johnson, A.B., Mapel, X.M., Marroquin-Flores, R.A., Martinez, T.E., McCullough, J.M., McLaughlin, J.E., Witt, C.C. Detecting turnover among complex communities using null models: a case study with sky-island haemosporidian parasites. Oecologia 195, 435–451 (2021). (doi: 10.1007/s00442-021-04854-6)

Research At A Glance: Haemosporidians are a diverse group of parasites that are found around the world. They can cause diseases, such as malaria, in humans and birds. Only five species of haemosporidians infect humans, but researchers have found over 3,000 lineages of haemosporidian parasites that can infect birds. Like what we see in humans, haemosporidian parasites can make birds sick and some birds are more likely to become infected, and die from that infection, than others. It is important for scientists to know which parasite lineages are likely to encounter and infect different bird species, so they can be prepared to help prevent infections and protect those species. One way to study this is to describe the community of haemosporidian parasites at different locations. However, it is not easy to sample such a diverse group of parasites. Haemosporidian parasites infect blood cells. This means that we needed to catch birds and obtain blood samples before we could determine the identity of their parasites. This is even more difficult because some parasites are very common, while others are rarer and might be easily missed if we do not catch many birds. Some parasites are also host specialists, meaning they may only occur in one or a few closely related birds. Others are host generalists and can infect many types of birds. These challenges needed to be addressed by sampling many birds at our study sites and by using a specific type of statistical analysis.

Our team set out to describe a community of haemosporidian parasites in the sky islands of the Southwestern United States. Sky islands refer to mountain ranges that have forest habitat at high elevations and desert habitat at low elevations. Like true islands separated by oceans, plants and animals that live in forests may not be able to move easily across desert habitats. We wanted to know if the parasite communities were different between these mountain ranges. To do this, we checked birds for parasitesusing two methods. We used molecular methods to isolate parasite DNA from bird blood cells and sequenced the DNA to find out which type of parasite had infected the bird. We also looked at blood samples using a microscope and photographed the parasites.

Once we had identified the parasites, we analyzed our data using a null modeling approach. This statistical approach allowed us to find out if the parasite communities were different between sky islands. This method also helped us to understand how our results were affected by our sampling. At the end of our study, we had sampled 776 birds. We found that 280 of them were infected with parasites and we found that some bird species were more infected than others. We found that parasite communities were different between the mountain ranges, even when the same species of birds were sampled. This result is interesting because it suggests that different populations of the same bird species will encounter different parasites across the area that the bird is found.

Highlights: One of the most important parts of this research was the way that we analyzed our data. The null modeling approach that we used was developed by Dr. Chris Witt and Selina Bauernfeind. Selina is the second author on our paper and was a post-baccalaureate researcher at the time. Our models ask whether the actual communities of parasites that we observed are different than we would expect if the parasites were randomly sampled from a single parasite community. This community represents our expectation under a null model, where there is no difference in the parasite lineages between sky islands. Selina developed this model by writing computer code in R. R is a type of statistical software that scientists often use to analyze data. She used the computer code to simulate 10,000 parasite communities under the null model.The null model statesthat there is no difference between sky islands. She then compared the simulated parasite communities to the observed parasite communities that we sampled during our study.

The main results are shown in Figure 1 and Figure 2. In both figures, the gray curves show the simulated parasitecommunities. The dotted line represents the results from our observed community, the parasites that we sampled. The stars (*) above the dotted line mean that the parasite community that we sampled is different from the community that we would have expected under the null model. Figure 1 shows that 56 parasite lineages were only found in one of the three mountain ranges. This number was higher than expected based on the null model, indicating that there were many unique parasite lineages in each mountain range. Only 19 parasite lineages were found in all three mountain ranges. This number was lower than expected based on the null model, suggesting that few parasites were shared across three mountain ranges. Taken together, our results suggest that the community of parasites was different between mountain ranges.

The figure shows three curves for the parasite lineages expected under the null model. For one mountain, most simulations found fewer lineages (the expected value) than the 56 lineages that the researchers observed. For two mountains, the observed number (25 lineages) was similar to the expected number of lineages. For all three mountain ranges, most simulations found more lineages than the 19 lineages observed.
Figure 1. The observed (dotted line) and expected (grey curve) number of parasite lineages found in one mountain range, two mountain ranges, or in all three mountain ranges studied. The stars (*) above the dotted line show that the parasite community that we sampled is different than the simulated parasite community. Adapted from Barrow et al. 2021.

Figure 2 shows the Jaccard dissimilarity index. It ranges from 0 to 1. Higher values show a greater difference between mountain ranges. As shown by the dotted line with the stars (*), the results show that the parasite community differed between Mount Taylor and the other two mountain ranges, Jemez and Zuni. The observed parasite communities in these mountain ranges had higher dissimilarity index values than expected under the null model.

The figure shows three curves for the parasite community differences between each pair of mountain ranges expected under the null model. A dotted line for each pair shows the observed parasite community differences. The observed difference between Mount Taylor and the Jemez Mountains was higher than expected under the null model. Similarly, the observed value between Mount Taylor and the Zuni Mountains was higher than expected under the null model.
Figure 2. The observed (dotted line) and expected (grey curve) parasite communities at the three mountain ranges studied: Mount Taylor, Zuni Mountains, and Jemez Mountains. The x-axis shows the Jaccard dissimilarity index. Adapted from Barrow et al. 2021.

What My Science Looks Like: Our team spent two years sampling birds in the field for this project. Our field set-up included plenty of supplies to record data, preserve samples for DNA analysis, and prepare blood smears to examine under the microscope.

A picture of six people sitting around two small tables in the piñon-juniper woodlands. There are test tubes on the table and a nitrogen tank in the background.
Here is a picture of some of the people in our field crew processing samples after a morning of collecting data. Pictured clockwise: Moses Michelsohn, Serina Brady, Chauncey Gadek, Jenna McCullough, Lisa Barrow, and John Ford.

Figure 3 shows the number of birds collected and the number of infections that we found at each of our three mountain ranges. “Individuals” refers to the number of birds that we caught, “host species” refers to the number of bird species that we caught, and “infected birds” refers to the number of birds that were infected with at least one haemosporidian parasite. Parahaemoproteus,denoted by “H”,were the most common haemosporidians we found (54 to 70 infections in each mountain range). Plasmodium,denoted by “P”, were theleast common haemosporidians we found (13 to 37 infections in each mountain range). The number of infected birds in each mountain range was similar, ranging from 87 to 93 birds.

An image that shows the state of New Mexico with locations for the three mountain ranges sampled in the northwestern part of the state. Birds were sampled at the transition zone between the piñon-juniper woodlands and the ponderosa pine forests at elevations ranging between 2,100-2,500 meters. The highest number of birds were sampled at Zuni Mountain (n=294) and Zuni also had the highest number of infected birds (n=93). The lowest number of birds were sampled at Jemez Mountain (n=207), which also had the lowest number of infected birds (n=87).
Figure 3. A figure that summarizes the locations for sample collection and the results of our 2-year study. It shows the number of birds and parasites found at the three mountain ranges: “H” stands for Parahaemoproteus,“P” stands forPlasmodium, and “L” stands for Leucocytozoon.Panel (b) shows the region of the United States that the samples were collected from. Panel (c) shows the elevation of the mountain ranges, where darker colors indicate higher elevations. Adapted from Barrow et al. 2021.

The Big Picture: Parasites are everywhere in the natural world. They can cause disease or death to hosts that they infect. It is important for researchers to study where parasites naturally occur, how widespread they are, and which host species they infect. Parasite communities are usually hard to describe because they are so diverse. If we do not sample all the bird species in an area or if we sample a different number of each bird species in each area, we may underestimate the number and type of parasites there. Our research took a new approach that helped to account for these types of problems. Our null modeling approach can be used by other researchers who want to ask similar questions. Our approach helped us understand the community of haemosporidian parasites in an area that has received little attention in the past. We found that the community of parasites can change between areas that are only tens of kilometers apart, even when the bird communities are similar. Our research helps us better understand parasite diversity and how that relates to host diversity.

Decoding the Language:

Fieldwork: Fieldwork is any type of research conducted outdoors. Examples of fieldwork include people who trap birds, measure plants, or collect water samples outside.

Generalists: Generalists are organisms that can use a wide variety of habitats, food sources, or environmental conditions. In the context of this study, generalist parasites can infect a wide variety of bird species.

Haemosporidians: Haemosporidians are microscopic parasites that can infect the blood cells of vertebrate animals (animals with a backbone). They have a unique structure called an apicoplast that allows the parasite to penetrate the blood cells of the host. These parasites are transmitted when the host is bitten by an insect. There are hundreds of described species and thousands of undescribed lineages.

Herpetofauna: Herpetofauna, or “herps”, are amphibians and reptiles.

Jaccard dissimilarity index: The Jaccard dissimilarity index is a metric that describes the difference between two ecological communities. The index ranges from 0 to 1, where low values show that the two communities have similar species and high values show a greater difference between communities.

Lineages: A lineage is a group of organisms descended from a common ancestor. Members of the same lineage are closely related and their genetic sequences are more similar to each other than to other lineages. A lineage can refer to several species, or it can refer to organisms that are not yet described as a species but are known to be closely related. In this study, haemosporidians are considered different lineages if their genetic sequence is different from other haemosporidian parasites.

Leucocytozoon: Leucocytozoon is a genus of haemosporidian parasite that infects birds. They are introduced to their avian host through the bite of an insect, most often a blackfly. More than 100 species of Leucocytozoon have been described.

Malaria: Malaria is an infectious disease caused by Plasmodium parasites that are transmitted by mosquitoes. This disease affects humans and other animals, including birds. Malaria causes tiredness, fever, headaches, and in severe cases, can result in death. Human malaria is most common in the tropics and subtropics, regions near the equator.

Museum collection: A museum collection is a set of objects that is catalogued and cared for by an institution or dedicated set of individuals. Museum collections can include art, historical objects, or scientific collections, like those at natural history museums. Collections can also include living collections of specimens, such as in zoos or seed banks. Natural history museum collections focus on specimens and parts of animals, plants, fungi, and other natural objects. These specimens are collected and cared for so that current and future generations can study, learn from, and have a record of the natural world.

Null model: The null modeling approach that we used is a statistical method. It is a way to analyze data. A null model describes the expectation that a certain process/event has not happened, or there is no difference between groups. It provides a reference point for comparison. In the context of this research, the null model suggests that there is no difference in parasite communities across mountain ranges. When a null modeling approach is used, researchers randomly sample datasets based on the expectations of the null model (that there is no difference between groups) and then compare that to the dataset that was observed in nature. In the context of this research, we randomly sampled from a pool of all the parasites that we found over the course of the study and compared that to the parasite communities that we found at each individual mountain range. If the values from the observed dataset fall outside the range of values from the randomly generated dataset, this suggests that the null model is not supported. In other words, if the parasites that we found at a particular mountain range look different than the parasites from the random dataset, we say that the null model is not supported and that the parasites are different between the mountain ranges.

Parahaemoproteus: Parahaemoproteus is a genus of haemosporidian parasites that primarily infects birds. They are introduced to their vertebrate host through the bite of an insect, most often a biting midge. More than 170 species have been described.

Plasmodium: Plasmodium is a genus of haemosporidian parasites that infects birds, lizards, and mammals. They are introduced to their vertebrate host through the bite of an insect, most often a mosquito. More than 200 species have been described, only five of which are known to infect humans. These parasites cause the disease malaria.

Post-baccalaureate researcher:  A post-baccalaureate researcher, or a “post-bac”, is a person who has completed their bachelor’s degree and has enrolled in a 1–2 year research-intensive program. Post-baccalaureate programs are offered across the country. They are professional development programs that help students transition into PhD programs.

Postdoctoral researcher: A postdoctoral researcher, or a “post-doc”, is a person who has completed their Ph.D., or doctoral degree, and continues to conduct  research. Postdoctoral research is often collaborative where the post-doc will work with other researchers and students, and often they are more independent. Usually, these researchers have significant training and skills, but are still considered to be early in their career stage. They may be continuing their training or gaining additional skills before beginning a more permanent position. A typical post-doc lasts for 2-3 years, and a person may complete more than one post-doc appointment, depending on their career goals.

Simulate: Scientists run simulations using computers. The computer will take a mathematical concept and a set of data to mimic what might happen in nature. In the context of this research, we created simulated datasets to describe what might happen in nature under the null model. In other words, these datasets describe what we expected if all the mountain ranges had similar parasite communities.

Sky island: The term “sky island” refers to a mountain range that has forest habitat at high elevations and is surrounded by desert habitat at low elevations. Like true islands separated by oceans, plants and animals that live in forests may not be able to move as easily across desert habitats. This landscape can result in isolated populations.

Specialists: In general ecology, specialists may use or specialize on a particular habitat, food source, or set of environmental conditions. In the context of this study, a specialist parasite only infects one species or a closely related bird species.

Learn More:

Arctos: Arctos is a museum collection management system where we make specimen data available. More information for each of the birds sampled in this project can be found through specimen links reported in our paper. See an example here.

MalAvi: MalAvi is the avian malaria database. All the haemosporidian parasite lineages that have been identified are reported here, along with their host species, geographic ranges, genetic sequences, and publications. New genetic sequences can be compared to the existing database to determine whether a particular parasite has been found before.

United States Geological Survey (USGS) information on avian malaria

Audubon article on avian malaria

Dr. Chris Witt’s lab webpage for those interested in this type of research

Synopsis edited by Rosario Marroquin-Flores, PhD (Anticipated: August 2022), Illinois State University, School of Biological Sciences and Madison Rittinger, PhD (Anticipated: May 2027), University of Wisconsin-Milwaukee, Department of Biological Sciences.

Download this article here

Please take a survey to share your thoughts about the article!