Haley Schluterman presents her research to the JV Roach Honors College. Haley Schluterman (BS Neuroscience 2020) presented her Senior Honors research project during a virtual event hosted by the JV Roach Honors College. Haley's research focused on uncovering the impacts of trenbolone, an androgen used to promote cattle growth and found in surface waters, on immune function in female fish. Great work, Haley! (December 2020)
The Jeffries lab presents their research at Society of Environmental Toxicology and Chemistry (SETAC) North America SciCon2 Meeting. Dr. Marlo Jeffries (Associate Professor of Biology), Julie Krzykwa (MS Biology 2017, PhD Biology 2020), Austin Bryant (MS Biology 2021), and Haley Schluterman (BS Neuroscience 2020) each delivered presentations at the virtual SETAC North America SciCon2 Meeting. Dr. Jeffries delivered a presentation, which was co-authored by Lynsey Malin (MS Biology 2020) and Vuong Do (BS Biology 2020), showing that exposures to anti-estrogenic compounds lead to alterations in cellular immune function. Haley's presentation, co-authored by Andrew Mielcuszny (BS Biology 2021), focused on the impacts of trenbolone, an environmentally-relevant androgen, on female fathead minnow immune function. Austin delivered a presentation detailing a portion of his thesis work showing that early life stage thyroid disruption leads to long-term alterations in the reproductive behaviors of male fathead minnows. Julie presented a portion of her dissertation work which showed that decreased body length and increased pericardial area are strong predictors of delayed mortality in fathead minnow embryos and should thus be utilized as additional fish embryo toxicity test endpoints. (November 2020)
Julie Krzykwa, PhD student in the Jeffries lab, publishes two articles related to her dissertation research. Julie Krzykwa (MS Biology 2017, PhD Biology 2020) and Dr. Marlo Jeffries (Associate Professor of Biology) published one article in Chemosphere entitled “Comparison of behavioral assays for assessing toxicant-induced alterations in neurological function in larval fathead minnows" (Vol. 257, pg. 126825; available here) and a second article in MethodsX titled "Development of a larval fathead minnow optomotor response assay for assessing visual function" (Vol 7, pg. 100971, available here). The articles present a subset of the results of experiments conducted as part of Julie’s PhD dissertation project, which sought to enhance the fish embryo toxicity (FET) test by determining whether easily observable alterations in eye size were indicative of adverse neurological effects. These papers describe efforts to refine and improve existing methods for evaluating ecologically-relevant behaviors, including those related to feeding, schooling, and predator avoidance, in larval fathead minnows. They also demonstrate the relative sensitivity of these assays for the detection of adverse neurological impacts. Overall, the results of these studies strengthen the existing framework for evaluating the neurological and behavioral impacts resulting from exposures to chemical contaminants. (October 2020)
Leah Thornton Hampton, PhD student in the Jeffries lab, publishes an article describing the transcriptomic responses of fathead minnows following bacterial infection. Leah (MS Biology 2015, PhD Biology 2020), Dr. Chris Martyniuk (University of Florida), Dr. Barney Venables (University of North Texas) and Dr. Marlo Jeffries (Associate Professor of Biology) published an article in Fish and Shellfish Immunology entitled “Advancing the fathead minnow (Pimephales promelas) as a model for immunotoxicity testing: Characterization of the renal transcriptome following Yersinia ruckeri infection" (Vol. 103, pg. 472-480; available here). This article details a portion of Leah's dissertation work which sought to further develop the fathead minnow as a model for immunotoxicity testing by identifying genes associated with key immune responses. Leah found that more than 1800 genes, many of which are associated with innate immunity, complement, hemorrhaging and iron absorption, were altered following infection. Future studies will be able to utilize the molecular targets identified in Leah's study to better understand the impacts of contaminants on pathogen-induced immune responses in fathead minnows, an emerging immunotoxicity model. (August 2020)
Leah Thornton Hampton, PhD student in the Jeffries lab, publishes an article detailing methods for evaluating cellular immune function in fathead minnows. Leah (MS Biology 2015, PhD Biology 2020), Dr. Marlo Jeffries (Associate Professor of Biology) and Dr. Barney Venables (University of North Texas) published an article in MethodsX titled “A practical guide for assessing respiratory burst and phagocytic cell activity in the fathead minnow, an emerging model for immunotoxicity" (Vol. 7, pg. 100992; available here). This article presents the results of Leah's efforts to refine cellular immune assays and provides detailed protocols for isolating immune cells, measuring phagocytic cell activity and assessing respiratory burst activity in the fathead minnow. (July 2020)
Dr. Jeffries and Leah Thornton Hamptom co-author a publication describing pesticide occurrence and ecological risk in the Syr Darya, a freshwater source that feeds the Aral Sea. Leah (MS Biology 2015, PhD Biology 2020) and Dr. Jeffries (Associate Professor of Biology), along with an international team of researchers from the University of Nebraska (Drs. Dan Snow and Shannon Bartelt-Hunt), University of Idaho (Dr. Alan Kolok), University of York (Dr. Brett Sallach), SRM Institute of Science and Technology – Tamil Nadu (Dr. Paromita Chakraborty), and Al-Frarabi Kazakh National University (Drs. Bolat Uralbekov and Bagdat Satybaldiev), published an article titled "Legacy and current pesticide residues in Syr Darya, Kazakhstan: Contamination status, seasonal variation and preliminary risk assessment" in Water Research (2020, Vol. 184:116141; available here). This article details a portion of an NSF-funded project, in which the presence of agrichemicals was evaluated in water and sediments collected from the Syr Darya, a river that feeds the ecologically-imperiled Aral Sea. Study results revealed that both modern-day and banned legacy pesticides are present in the river and that these contaminants pose a significant risk to the health of aquatic organisms. The information gained through this study identifies environmental factors that warrant consideration given ongoing efforts aimed at restoring the Syr Darya and the Aral Sea. (July 2020)
Haley Schluterman, Andrew Mielcuszny, and Austin Bryant receive grants to support their research. Haley (BS Neuroscience 2020) received $1500 from the JV Roach Honors College to support her senior thesis research which aims to uncover the impacts of trenbolone, an androgenic chemical associated with cattle production and detected in surface waters downstream of cattle feedlots, on immune function in fathead minnows. Andrew (BS Biology 2021) was awarded $1000 in College of Science and Engineering (CSE) SERC funds to support his work which seeks to examine sex-based differences in cellular immune function. Austin (MS Biology 2021) was awarded $1000 to support his thesis research which seeks to better understand the impacts of early-life-stage thyroid disruption on neurodevelopment and behavior. Congrats to Haley, Andrew, and Austin! (June 2020)
Julie Krzykwa (Biology MS 2017) successfully defends her PhD dissertation thesis and obtains position with Smithers Environmental Risk Science. Julie successfully defended her dissertation entitled "Development of cardiovascular and neurodevelopmental metrics as sublethal endpoints for the fish embryo toxicity test" via video conference. Her research aimed to enhance the fish embryo toxicity (FET) test by investigating the utility of several neurodevelopmental and cardiovascular metrics as potential FET test endpoints. Julie found that pericardial area, a measure of pericardial edema severity, is a strong predictor of mortality. Further, when used as an endpoint, pericardial area improves the predictive ability of the FET test making it more comparable to the toxicity tests currently utilized by regulatory agencies. Over the course of her graduate career, Julie delivered 12 presentations at regional, national and international meetings, received three presentation awards, obtained over $17,000 in research and travel funding, and published three papers. She currently has two manuscripts in review and two in preparation. Julie will begin her professional career in the Ecotoxicology Department at Smithers Environmental Risk Science LCC in Wareham, Massachusetts in June. Congrats to Julie! (April 2020)
Lynsey Malin (Biology BS 2018) successfully defends her Master's thesis. Lynsey Malin successfully defended her MS thesis entitled “Hormones and immunity: What is the role of estrogen in immune function?” via video conference. Her thesis research investigated the impacts of fadrozole, an estrogen-suppressing pharmaceutical, on various aspects of immune function in female fathead minnows. Her data suggest that estrogen suppression induced via fadrozole exposure had little impact on pathogen resistance, hematological parameters, or the expression of genes related to inflammation and complement activation. However, her results provided limited evidence suggesting that reductions in estrogen signaling may influence cellular immune functions, including phagocytosis and respiratory burst. Lynsey is currently drafting a manuscript detailing her research for journal submission over the summer. In the late summer, she will begin medical school at the University of Minnesota. Way to go, Lynsey! (April 2020)
Leah Thornton Hampton (Biology MS 2015) successfully defends her PhD dissertation and obtains a position with the Southern California Coastal Water Research Project. Leah, a PhD student in the Department of Biological Sciences at the University of North Texas co-advised by Dr. Barney Venables (UNT) and Dr. Jeffries (TCU) successfully defended her dissertation titled “The Consequences of Early Life Stage Thyroid Suppression on Immune in the Fathead Minnow (Pimephales promelas)” via video conference. Her dissertation research developed and optimized methods for assessing cellular immune function in fathead minnows, characterized global gene expression changes experienced by fish infected with a bacterial pathogen in an effort to identify key immune process for further study in this species, and demonstrated the long-term outcomes of early life stage thyroid disruption on various aspects of immune function measured from the molecular to whole-organism levels. Her work has advanced the utility of the fathead minnow as a model system for the study of immunotoxicity and contributes to our understanding of the role that thyroid hormones play in development of the immune system. Over the entirety of her graduate career, Leah delivered 22 presentations at regional, national and international meetings, received 6 presentation awards, obtained over $7000 in research and travel funding, and published five papers. She currently has three manuscripts in review, two of which are related to her dissertation work, and an additional paper in preparation. Leah recently began her new position as a Scientist in the Toxicology Department at the Southern California Coastal Water Research Project (SCCWRP). To learn more about Leah, see this profile that SCCWRP published in their Spring 2020 Director’s Report. Congrats to Leah! (March 2020)