Past Announcements

Evan Burchfiel receives SERC funding. Evan Burchfiel (BS Biology 2023) receives $1071 in funding from the TCU College of Science and Engineering to support his senior thesis research titled "Validation of the REACTIV assay for the detection of estrogenic chemicals". Evan's project is part of an international ring trail, led by collaborators at Laboratoire Watchfrog (France), aimed at validated a novel assay, which uses transgenic Japanese medaka embryos to detect chemicals with estrogenic activity. Great work, Evan! (November 2021)

Dalton Allen successfully defends his Master's thesis and begins PhD program. Dalton Allen (MS Biology 2020, PhD Biology 2024) presented and defended his thesis titled "Metals in the Syr Darya and Shardara Reservoir, Kazakhstan: An environmental and human health risk assessment." For his project, Dalton utilized data collected in 2015 by Dr. Jeffries and a team of international collaborators from University of Nebraska and Al-Farabi Kazakh National University to conduct ecological and human health risk assessments to determine the potential for metals present in the Shardara Reservoir to adversely impact the fishery and those consuming the fish. His results show that high levels of metals present in the surface waters of the Reservoir are likely to pose a risk to the health of the fishery; however, no risk to consumers of the fish were identified. Dalton's work contributes to a growing body of work aimed at better understanding the presence and impacts of contaminants in aquatic systems in Central Asian countries like Kazakhstan. (July 2021)

Leah Thornton Hampton, a PhD student from the Jeffries lab, publishes an article related to her dissertation work. Leah (MS Biology 2015, PhD Biology 2020), Miranda Finch (BS 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 Scientific Reports titled "Developmental thyroid disruption causes long-term impacts on immune cell function and transcriptional responses to pathogen in a small fish model". The article describes work aimed at better understanding the long-term consequences of early-life-stage exposures to thyroid disrupting chemicals on immune function in fish. Leah's results show that developmental thyroid disruption leads to long-term alterations in key immune process at both the molecular and cellular levels. These findings show that normal thyroid hormone signaling is essential for immune system development in fish and also confirm that the immune system is an indirect target of thyroid disrupting chemicals. (July 2021)

Jeffries lab awarded AALAS grant to support research aimed at developing marine toxicity tests that are more protective of animal welfare. Dr. Marlo Jeffries (Associate Professor of Biology) and co-PI Dalton Allen (MS Biology 2021, PhD Biology 2024) were awarded a $10,164 grant from the American Association of Laboratory Animal Sciences to support portions of Dalton's dissertation work, as well as several undergraduate senior thesis projects, which aim to determine whether toxicological tests that feature marine fish embryos or invertebrates can replace those that feature marine fish larvae. This line of research is timely given recent legislative demands that call for improvements in the welfare of animals utilized in routine toxicity testing. Ultimately, this research will provide regulatory agencies with the data needed to adopt test protocols that are not only robust enough to ensure adequate protection of aquatic resources, but that also protect the welfare of organisms utilized in such protocols. (June 2021)

The Jeffries lab publishes a study evaluating methods of assessing swim performance in larval fish. Julie Krzykwa (MS Biology 2017, PhD Biology 2017), Gabby Lamanteer (BS Biology 2020), and Dr. Marlo Jeffries (Associate Professor of Biology) published an article titled "A comparison of two methods for estimating critical swimming speed (Ucrit) in larval fathead minnows: the laminar flow assay and the spinning task assay" in Journal of Experimental Biology. The article describes research aimed at determining optimal methods for evaluating swim performance, a metric of cardiovascular health and overall fitness, in larval fathead minnows. The results of the study showed that traditional "laminar flow" assays are superior to newer "spinning task" assays. To learn more, check out the article here. (May 2021)

Undergraduate students in the Jeffries lab receive SERC awards. Kyle Horton (BS Biology 2022), Kahler Doyle (BS Biology 2022), and Michaela Kelly (BS Biology 2022) received funding through the TCU College of Science and Engineering to support their Senior Thesis Research. Kyle's project titled "Advancing the fathead minnow as a model for immunotoxicity: Can Aeromonas species be used in pathogen challenges?" received $1216 in support. A project titled "Development of a new infection model for fathead minnows, an emerging immunotoxicity model organism", led by Kahler, received $987. And, Michaela's project, called "Development of new approaches for marine toxicity testing", was awarded $1071. Kyle, Kahler, and Michaela will work on these projects for the next year or so before presenting their findings to fulfill the requirements for graduating with Honors in Biology. Way to go Kyle, Kahler and Michaela! (April 2021).

Austin Bryant successfully defends his Master's thesis. Austin (MS Biology 2020) successfully presented and defended his thesis to earn his MS degree. Austin's thesis research sought to determine whether early-life-stage thyroid disruption alters key behaviors in fathead minnows, an ecotoxicological model organism. The results of his work show that thyroid disruption induced by the model thyroid suppressant, propylthiouracil (PTU), lead to alterations in male reproductive behavior. This finding explains previous research carried out in the Jeffries lab which showed that developmental exposures to PTU lead to significant reductions in offspring production. Furthermore, it demonstrates the need to consider the long-term consequences of exposures to thyroid disrupting chemicals on reproduction and reproductive behavior. (May 2021)

Julie Krzykwa, a PhD student from the Jeffries lab, publishes an article stemming from her dissertation research. Julie Krzykwa (MS Biology 2017, PhD Biology 2020), Sarah King (BS Biology 2020), and Dr. Marlo Jeffries (Associate Professor of Biology) published an article in Environmental Science and Technology entitled “Investigating the predictive power of three potential sublethal endpoints for the fish embryo toxicity test: snout-vent length, eye size and pericardial edema." (Vol. 55, pg. 6907-6916; available here). The article presents 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 morphological changes are predictive of adverse fitness outcomes. The results of this study revealed that alterations in embryo eye size were not predictive of adverse effects, but that reduced body length and the development of pericardial edema were predictive of mortality. These findings indicate that the addition of body length and pericardial edema as FET test endpoints would improve the sensitivity of the fathead minnow FET test making it a more robust tool for predicting the toxicity of chemicals and effluents. (April 2021)

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)

Jeffries lab awarded grant by AALAS to develop toxicity testing methods that enhance animal welfare. Dr. Jeffries was awarded a $27,192 Grant for Laboratory Animal Science (GLAS) by the American Association for Laboratory Animal Science (AALAS) for a project entitled “Towards the 3R’s in fish toxicity testing”. The proposed research aims to improve the welfare of fish used in routine chemical and effluent toxicity tests by developing new testing strategies that reduce the number of organisms used or refining existing test methods to minimize fish distress. The Jeffries lab will determine whether toxicity tests conducted with fathead minnow embryos are as sensitive and robust as current test methods that use larval minnows. In addition, the work will determine whether the inclusion of sub-lethal endpoints (such as growth, developmental abnormalities or altered gene expression patterns) can enhance the utility of embryo toxicity tests. Ultimately, this project seeks to provide regulatory agencies, such as the Environmental Protection Agency, with a toxicity testing method that allows for the protection of human and environmental health, while simultaneously improving the welfare of fish used in such tests. (May 2015)

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)

Students from the Jeffries lab present their research at Society of Environmental Toxicology and Chemistry (SETAC) North America Meeting. Abbey Johnson (MS Biology 2019), Julie Kryzkwa (MS Biology 2017, PhD Biology 2020), and Leah Thornton Hampton (MS Biology 2015, PhD Biology 2020) each delivered platform presentations at the SETAC North America Meeting in Toronto, Canada. Abbey delivered a presentation describing the results of a transcriptomics study, co-authored Peter Bruns (MS Biology 2018) and Dr. Matt Hale, showing that early life stage thyroid disruption in fathead minnows alters the expression of key genes involved in ovarian development. Julie’s presentation, co-authored by Gabby Lamanteer (BS Biology 2020), focused on the development and validation of behavioral assays for assessing neurotoxicity in larval fathead minnows. Leah delivered a platform presentation, co-authored by Miranda Finch (BS Biology 2020), Dr. Barney Venables (University of North Texas) and Dr. Chris Martyniuk (University of Florida), detailing a portion of her dissertation work showing that early life stage thyroid disruption leads to long-term alterations in immune cell signaling and function. She also presented a poster describing her efforts to optimize cellular assays for the assessment of immune cell function in fathead minnows, an emerging model for immunotoxicity. While at the meeting, Dr. Jeffries co-chaired a full-day session on Immunotoxicity and gave a presentation during the closing ceremony encouraging meeting participants to attend the 2020 SETAC North American meeting, which will be co-chaired by Dr. Jeffries and held here in Fort Worth.

Dalton Allen receives a College of Science and Engineering Graduate Student SERC grant. Dalton (MS Biology 2022) was awarded a graduate student SERC grant to support his research aimed at developing alternative methods for marine effluent toxicity testing that enhance the welfare of fish used in such assessments. Specifically, his work will evaluate the potential for toxicity tests that utilize opossum shrimp, sheepshead minnow embryos, or inland silverside embryos to replace tests that feature larval fish. Great work, Dalton! (October 2019)

Several members of the Jeffries labs present their research at the South Central Society of Environmental Toxicology and Chemistry Meeting; April Tran and Miranda Finch receive presentation awards. Several members of the Jeffries lab attended the South Central Society of Environmental Toxicology and Chemistry. The meeting, which featured 23 student platform presentations and 29 student poster presentations, was held at Baylor University in Waco, TX. Leah Thornton Hampton (MS Biology 2015, PhD Biology 2020), Julie Kryzkwa (MS Biology 2017, PhD Biology 2020), Abbey Johnson (MS Biology 2019) and April Tran (BS Biology 2019) delivered platform presentations detailing their research, while Miranda Finch (BS Biology 2020), Hannah Nettelblad (BS Biology 2019) and Caroline Wade (BS Biology 2019) presented posters. April received 3rd Place Best Platform for her research demonstrating the impacts of thyroid disruption on immune cell development and function. Miranda received 2nd Place Best Poster for her work investigating sex-specific differences in the immune responses of fathead minnows, an emerging model for immunotoxicity studies. Great work all and congrats o April and Miranda! (May 2019)

Julie Krzykwa, PhD student in the Jeffries lab, publishes research aimed at identifying endpoints indicative of neurotoxicity in fish embryos. Julie Krzykwa (MS Biology 2017, PhD Biology 2020), Asal Saied (BS Biochemistry 2020) and Dr. Marlo Jeffries (Associate Professor of Biology) published an article in Ecotoxicology and Environmental Safety entitled “Identifying sublethal endpoints for evaluating neurotoxic compounds utilizing the fish embryo toxicity test” (Vol. 170, pg. 521-529). The article presents the results of experiments, conducted as part of Julie’s MS thesis project, aimed at advancing the fish embryo toxicity (FET) test, which is considered a more humane alternative to toxicity tests that utilize older fish. Julie’s research confirms that fish embryos are less sensitive to some neurotoxic compounds than older fish, but that the inclusion of sublethal endpoints (including eye size and pericardial edema) can enhance FET test performance in some cases. The article can be viewed here. (April 2019)

Students from the Jeffries lab present 6 posters at the TCU College of Science & Engineering Student Research Symposium; Miranda Finch wins the Best Undergraduate Biology Poster award. Graduate students, Julie Krzykwa (MS Biology 2017, PhD Biology 2020) and Abbey Johnson (MS Biology 2019), and undergraduate students Miranda Finch (BS Biology 2020), Hannah Nettelblad (BS Biology 2019), April Tran (BS Biology 2019) and Caroline Wade (BS Biology 2019) each presented posters on their research at the annual TCU Student Research Symposium. Miranda received the Best Undergraduate Poster presentation award for her work highlighting sex specific differences in the immune responses of fathead minnows. Way to go Julie, Abbey, Miranda, Hannah, April and Caroline! (April 2019)

Miranda Finch, Gabby Lamanteer and Lynsey Malin receive College of Science and Engineering SERC grants. Miranda (BS Biology 2020) was awarded a SERC grant to support her research aimed at uncovering the sex specific immune responses of fathead minnows, an emerging immunotoxicity model, while Gabby (BS Biology 2020) was awarded funds to support her research which will compare two methods for assessing swim performance in larval-juvenile fathead minnows. Graduate student Lynsey Malin (BS Biology 2019, MS Biology 2020) received funds to investigate the role that estrogens play in immunity. Excellent work, Miranda, Gabby and Lynsey! (April 2019)

Abbey Johnson defends her thesis and fulfills the requirements of the MS degree. Abbey Johnson, an MS student co-advised by Dr. Jeffries and Dr. Matt Hale, successfully defended her MS thesis and delivered a presentation outlining her project to the Biology Department. For her thesis research, Abbey utilized next-generation sequencing to investigate the impacts of early life stage thyroid disruption on global gene expression patterns in the brain to better understand the connection between developmental hypothyroidism, behavior and reproductive success. We are super proud of you, Abbey! (April 2019)

Three students from the Jeffries lab deliver their Honors Thesis Presentations. In fulfillment of the requirements for achieving Departmental Honors in Biology, Hannah Nettelblad (BS Biology 2019), April Tran (BS Biology 2019) and Caroline Wade (BS Biology 2019) delivered public presentations detailing their senior thesis projects at the TCU College of Science and Engineering Honors Research Symposium. Congrats to Hannah, April and Caroline for their completion of this milestone! (March 2019)

Jeffries lab publishes research demonstrating that gonadosomatic index is a confounding factor in fish-based endocrine disruption screening assays. Kyle Roush (BS Biology 2016, MS Biology 2018) and Dr. Jeffries published an article in Environmental Toxicology and Chemistry entitled “Gonadosomatic index as a confounding variable in fish-based screening assays for the detection of anti-estrogens and nonaromatizable androgens” (Vol. 38, pg. 603-615). The article presents the results of experiments aimed at determining whether females with high and low gonadosomatic indices (GSI, an indicator of ovary size) differ in their responses to endocrine disrupting compounds. Overall, the work shows that ovary size influences the way in which females respond to both anti-estrogenic and androgenic compounds, highlighting the need to account for GSI in the design of endocrine disruption studies featuring female fish. The article can be viewed here. (February 2019)

Dr. Jeffries recognized as a top reviewer for Environmental Toxicology and Chemistry. Dr. Marlo Jeffries was named as an Exceptional Reviewer of 2018 by Environmental Toxicology and Chemistry (ET&C). This honor recognizes the top 15 reviewers, out of nearly 850, for the quality and quantity of the manuscript reviews that they complete. Her receipt of this recognition appears in the January volume of ET&C. (January 2019)

Jeffries Lab presents research at the Society of Environmental Toxicology and Chemistry (SETAC) North America Meeting. The Jeffries lab delivered three platform presentations and five poster presentations at the SETAC North America meeting in Sacramento, CA. Leah Thornton (MS Biology 2016, PhD Biology 2020) gave two poster presentations – one detailing a novel visual method for assessing thyroid hormone levels in fathead minnow larvae and one describing the impacts of early life stage thyroid disruption on immune function. Julie Krzykwa (MS Biology 2017, PhD Biology 2020) presented a poster on her work aimed at developing methods for measuring several behaviors indicative of neurotoxicity in larval fathead minnows, while Lynsey Malin (BS Biology 2018, MS Biology 2020) presented a poster, co-authored by Miranda Finch (BS Biology 2019), describing the impacts of estrogen exposure on male immunity. Kyle Roush (BS Biology 2016, MS Biology 2018) delivered platform and poster presentations describing that female sexual maturity status and male sexual ornamentation are confounding factors in endocrine disruption screening assays, respectively. Abbey Johnson’s (MS Biology 2019) platform presentation described her thesis project, which seeks to uncover the mechanisms underlying hypothyroidism-induced reductions in reproductive output in fathead minnows. Dr. Jeffries gave a platform presentation showing the influence of sex and sexual maturity status on basic aspects of immune function in fathead minnows. In addition, Kyle and Abbey received travel awards from SETAC to support their attendance at the meeting. (November 2018)

Jeffries Lab publishes paper aimed at identifying potential endpoints for use in the fish embryo acute toxicity test. Julie Krzykwa (MS Biology 2017, PhD Biology 2020), Alexis Olivas (BS Biology 2017) and Dr. Jeffries published an article in Environmental Toxicology and Chemistry entitled: “Development of Cardiovascular and Neurodevelopmental Metrics as Sublethal Endpoints for the Fish Embryo Toxicity Test.” The article presents research describing methods for measuring cardiovascular and neurological endpoints in fathead minnow embryos and provides evidence indicating that the inclusion of sublethal endpoints may improve the sensitivity of the fish embryo acute toxicity test, which has been proposed a more humane alternative to toxicity tests featuring older fish. The article can be viewed here. (October 2018)

Hannah Nettelblad receives College of Science and Engineering SERC grant. Hannah (BS Biology 2019) was awarded a SERC grant to support her research aimed at determining whether early life stage exposures to the common environmental contaminant, nitrate, influence sexual development and reproductive function. Way to go, Hannah! (Octover 2018)

Jeffries lab publishes research on the impacts of flame retardants on immune function. Leah Thornton (MS Biology 2015, PhD 2020), Elise Path (BS Biology 2016), Gunnar Nystrom (BS Biology 2017), Dr. Barney Venables (professor at UNT) and Dr. Jeffries, published an article in Fish and Shellfish Immunology entitled “Embryo-larval BDE-47 exposure causes decreased pathogen resistance in adult male fathead minnows (Pimephales promelas)” (Vol. 80, p. 80-87). The article details research showing that early life stage exposures to the flame retardant BDE-47 lead to altered pathogen resistance in male fathead minnows. The article can be viewed here. (May 2018)

Jeffries Lab presents research at the South Central Society of Environmental Toxicology and Chemistry (SETAC) Meeting; Kyle Roush and Leah Thornton receive presentation awards. The Jeffries lab delivered two platform presentations and three poster presentations at the South Central SETAC meeting in Junction, TX. Kyle Roush (BS Biology 2016, MS Biology 2018) and Mallory Seemann (BS Biology 2018) each gave platform presentations detailing their projects, while Lydia Stephens (BS Biology 2018), Julie Krzykwa (MS Biology 2017, PhD Biology 2020), and Leah Thornton (MS Biology 2016, PhD Biology 2020) each presented posters. Leah received 1st place Best Poster award for her work detailing a novel method for visualizing thyroid hormones in larval fathead minnows. Kyle received 1st place Best Platform award for his presentation on the influence of female sexual maturity status on biomarker responses to endocrine disrupting compounds. Good work Leah and Kyle! (April 2018)

April Tran and Asal Saeid receive College of Science and Engineering SERC grants. April (BS Biology 2019) was awarded a SERC grant to support her research aimed at assessing the impacts of embryo-larval hypothyroidism on immune cell development and function. Asal was awarded funds to support her research aimed at identifying and assessing the thyroid disrupting effects of triclosan byproducts. Excellent work, April and Asal! (April 2018)

Undergraduates from the Jeffries lab present 4 posters at the TCU College of Science & Engineering Student Research Symposium; Mallory Seemann wins the Best Undergraduate Biology Poster award. Bethany Pierce (BS Biology 2018), Mallory Seemann (BS Biology 2018), Ari Soto (BS Biology 2018), and Lydia Stephens (BS Biology 2018) each presented posters on their research at the annual TCU Student Research Symposium. Mallory received the Best Undergraduate Poster presentation award for her work demonstrating the impacts of early life stage thyroid disruption on male reproductive capacity. Great job, Ari, Bethany, Lydia and Mallory! (April 2018)

Kyle Roush authors publication detailing research aimed at optimizing the fathead minnow fish embryo toxicity (FET) test. Kyle (BS Biology 2016, MS Biology 2018) along with co-authors, Julie Krzykwa (MS Biology 2017, PhD Biology 2020), Jacob Malmquist (BS Biology, 2016), Dane Stephens (BS Biology 2015) and Dr. Jeffries, published an article in Ecotoxicology and Environmental Safety entitled “Enhancing the fathead minnow fish embryo toxicity test: Optimizing embryo production and assessing the utility of additional test endpoints” (Vol. 153, p. 45-53). The article presents research describing improved methods for producing fathead minnow embryos and provides evidence indicating that the inclusion of sublethal endpoints may improve FET test sensitivity. The article can be viewed here. (January 2018)

Julie Krzykwa is selected as the recipient of the Procter & Gamble/Society of Environmental Toxicology and Chemistry Student Fellowship Award. Julie (MS Biology 2017, PhD Biology 2020) was selected as the P&G/SETAC Fellow for 2010. As part of the fellowship, Julie received $15,000 to support her dissertation research project entitled "Advancing animal alternatives in toxicity testing: The use of developmental abnormalities in fish embryos to predict chronic toxicity and adverse outcome". Julie's accomplishment was celebrated during the opening ceremony of the SETAC North America meeting in Minneapolis, MN. Great job, Julie! (November 2017)

Jeffries Lab attends the Society of Environmental Toxicology and Chemistry (SETAC) North America Meeting in Minneapolis, MN. The Jeffries lab delivered two platform presentations and four poster presentations at the SETAC meeting. Leah Thornton (MS Biology 2015, PhD 2020) and Peter Bruns (MS Biology 2017) each gave platform presentations detailing aspects of their research, while Kyle Roush (BS Biology 2016, MS Biology 2018), and Julie Krzykwa (MS Biology 2017, PhD Biology 2020). Way to go Leah, Peter, Kyle and Julie! (November 2017)

Ari Soto receives College of Science and Engineering SERC grant. Ari Soto (BS Biology 2018) was awarded a $1500 SERC grant to support her research aimed at determining whether differences in disease resistance and immune function between males and females is related to differences in estrogen levels. (October 2017)

Jeffries Lab presents research at the South Central Society of Environmental Toxicology and Chemistry (SETAC) Meeting; Leah Thornton and Peter Bruns receive recognition for their presentations. The Jeffries lab delivered two platform presentations and three poster presentations at the South Central SETAC meeting in Houston, TX. Julie Krzywka (MS Biology 2017) and Peter Bruns (MS Biology 2017) each gave platform presentations detailing their thesis projects, while Haley Egan (BS Neuroscience 2017), Kyle Roush (BS Biology 2016, MS Biology 2018), and Leah Thornton (MS Biology 2016, PhD Biology 2020) each presented posters. Leah received 3rd place Best Poster award for her poster, co-authored by Meriel LeSueur (BS Biology 2017), on the effects of thyroid hormone inhibition on immune responses and disease resistance in fathead minnows. Peter received 3rd place Best Platform award for his talk on the effects of early life stage thyroid disruption on sexual development and reproductive function. Good work Leah and Peter! (April 2017)

Jeffries Lab give 7 poster presentations at the College of Science and Engineering Student Research Symposium and Meriel LeSueur wins Best Undergraduate Biology Poster. Graduate students, Julie Krzywka (MS Biology 2017), Peter Bruns (MS Biology 2017) and Kyle Roush (BS Biology 2016, MS Biology 2018), and undergraudates, Haley Egan (BS Neuroscience 2017), Meriel LeSueur (BS Biology 2017), Gunnar Nystrom (BS Biology 2017) and Alexis Olivas (BS Biology 2017) each presented posters detailing their research. Meriel was nominated for the SciCom Award for Best Lay Communication and recieved the Best Undergraduate Biology Poster award. Way to go Julie, Peter, Kyle, Gunnar and Alexis! And, congrats to Meriel! (April 2017)

Bethany Pierce and Mallory Seemann receive College of Science and Engineering SERC Awards and JV Roach Honors College Undergraduate Research Grants. Bethany Pierce (BS Biology 2018) and Mallory (BS Biology 2018) received $3000 each to support their Honors research from SERC funds and Honors College Undergraduate Research grants. Bethany's funding will be utilized to uncover the impacts of exposures to the environmentally-relevant thyroid disrupting compounds, triclosan and perchlorate, on eye development and function in embryonic and larval fathead minnows. Mallory's funds will support a project aimed at uncovering the impacts of early life stage thyroid disruption on bone development, as well as the underlying mechanisms responsible for altered bone formation. (April 2017)

Meriel LeSueur and Gunnar Nystrom receive recognition for their Honors Thesis presentations. Following their public presentations of the Honors projects during the College of Science and Engineering, Meriel LeSueur (TCU, BS Biology, 2017) received an Honorable Mention for Best Presentation and Gunnar Nystrom (TCU, BS Biology, 2017) was named as a Boller finalist. Of the over 100 Honors presentations given, Gunnar won the University-wide Boller Competition for Best Honors Presentation. Congrats to Gunnar and Meriel! (April 2017)

The Jeffries lab publishes a paper aimed at developing the fathead minnow as a model organism for immunotoxicity assessments. Leah Thornton (TCU, MS Biology, 2015) and co-authors, Meriel LeSueur (TCU, BS Biology, 2017), Ally Yost (TCU, BS Biology, 2015), Dane Stephens (TCU, BS Biology, 2015) Dr. Jeffries, published an article in Fish and Shellfish Immunology entitled “Characterization of basic immune function parameters in the fathead minnow (Pimephales promelas), a common model in environmental toxicity testing” (Vol. 61, February 2017, p. 163-172). The article represents the first step in developing the fathead minnow as a model for immunotoxicity assessments. The article can be viewed here. (January 2017)

Ally Yost authors publication detailing the effects of BDE-47 on metamorphosis and thyroid signaling in tadpoles. Ally (TCU, BS Biology, 2015) along with co-authors, Leah Thornton (TCU, MS Biology, 2015), Dr. Barney Venables (UNT, Professor) and Dr. Jeffries, published an article in Environmental Toxicology and Pharmacology entitled “Dietary exposure to polybrominated diphenyl ether 47 (BDE-47) inhibits development and alters thyroid hormone-related gene expression in the brain of Xenopus laevis tadpoles” (Vol. 48, December 2016, p. 237-244). The article outlines Ally's Senior Thesis project which showed that exposures to BDE-47, a common flame retardant, during early development hinder metamorphosis and alter thyroid hormone signaling in the brain. The article can be viewed here. (December 2016)

Jeffries Lab gives several presentations at the Society of Environmental Toxicology and Chemistry meeting; Julie Krzykwa, Gunnar Nystrom and Kyle Roush receive recognition for their presentations. Peter Bruns (MS 2017), Julie Krzykwa (MS 2017), Gunnar Nystrom (BS 2017), Elise Path (BS 2016), Kyle Roush (BS 2016, MS 2018) and Dr. Jeffries attended and authoured/co-authored eight platform presentations and two poster presentations at the Society of Environmental Toxicology and Chemistry 7th World Congress/37th North America Meeting in Orlando, FL.
Julie was awarded 3rd Place Best Masters student Platform for her presentation on the use of cardiovascular and neurological endpoints to assess toxicity in fish embryos. Gunnar Nystrom received 3rd Place Best Undergraduate Student Platform for his presentation on the biological impacts of agrichemicals on fish collected from the Syr Darya River in Kazakhstan and Kyle Roush received 2nd Place Best Undergraduate Student Platform for a presentation detailing his senior thesis research on utilizing the fish embryo toxicity test as a replacement for test methods that utilize larval fish. (November 2016)

Jeffries Lab gives three presentations at the Lone Star Chapter of the Society of Toxicology Meeting; Julie Krzykwa receives presentation award. Three members of the Jeffries lab, Leah Thornton (UNT PhD student co-advised by Dr. Jeffries), Julie Krzykwa (Biology MS, 2017) and Meriel LeSueur (Biology BS, 2017) attended and presented their research at the Lone Star Chapter of the Society of Toxicology Meeting in Waco, TX. Leah presented a poster detailing her research aimed at uncovering the impacts of flame retardant chemicals on immune system development, while Meriel presented a poster on her Senior Thesis project aimed at determining the impacts of chemically-induced thyroid disruption on adult immunity and disease resistance in a common fish model. Julie gave a platform presentation outlining her efforts to expand the utility of fish embryo toxicity tests through the inclusion of endpoints associated with cardiovascular and neurological development. Julie received the 2nd Place Best Student Platform Presentation Award. (October 2016)

Leah Thornton authors publication detailing the effects of BDE-47 on sexual development and reproduction in fathead minnows. Leah (TCU, MS Biology, 2015) along with co-authors, Elise Path (TCU, BS Biology, 2016), Gunnar Nystrom (TCU, BS Biology and BS Business, 2017), Dr. Barney Venables (UNT, Professor) and Dr. Jeffries, published an article in Environmental Science and Technology entitled “Early life stage exposure to BDE-47 causes adverse effects on reproductive success and sexual differentiation in fathead minnows (Pimephales promelas)” (Vol. 50, July 2016, p. 7834-7841). The article presents research showing that exposures to BDE-47, a common flame retardant, during early development alter sexual development and impair reproductive success in fathead minnows, an environmental sentinel organism. The article can be viewed here. (July 2016)

Jeffries lab publishes an article on the impacts of flame retardants on fish reproduction. Leah Thornton (TCU, MS Biology, 2015), Elise Path (TCU, BS Biology, 2016), Dr. Barney Venables (UNT, Professor) and Dr. Jeffries published an article in Environmental Toxicology and Chemistry entitled “The endocrine effects of dietary BDE-47 exposure, measured across multiple levels of biological organization, in breeding fathead minnows” (Vol. 35, Issue 8, August 2016, p. 2048-2057). The article describes research showing the impacts of polybrominated diphenyl ether 47, a commonly detected flame retardant in aquatic systems, on various aspects of reproduction in adult fish. The article can be viewed here. (July 2016)

Jeffries lab publication nominated for Environmental Toxicology and Chemistry Best Paper of 2015. An article titled “The fish embryo toxicity test as a replacement for the larval growth and survival test: A comparison of test sensitivity and identification of alternative endpoints in zebrafish and fathead minnows” authored by Marlo Jeffries (Assistant Professor of Biology) and co-authored by Dane Stephens (BS Biology 2015) was nominated for Best Paper of 2015 by Environmental Toxicology and Chemistry (ET&C). Of the over 325 articles published in ET&C in 2015, 23 were nominated for a Best Paper Award. Nominations are made by the journal’s editors, with input from journal reviewers, in an effort to recognize innovative papers with rigorous and relevant science with the potential to impact the fields of environmental toxicology and chemistry. (June 2016)

The Jeffries lab attends the South Central Society of Environmental Toxicology & Chemistry meeting, presenting four platforms and six posters. Gunnar Nystrom (a Junior Biology and Business major), Elise Path (a senior Biology major), Kyle Roush (a Senior Biology and Criminal Justice major) and Leah Thornton (15' MS in Biology) gave platform presentations at the annual regional meeting held on TCU's campus. Julie Kryzkwa (MS student) and Peter Bruns (MS student), Jacob Malmquist (a Senior Biology major), Kate Phillips (a Senior Neuroscience major) and Ali Medders (a Senior Biology major) and Ally Yost (15' BS in Biology and Environmental Science) presented posters at the meeting. Julie received the 2nd Place Best Student Poster award, while Elise was awarded 3rd Place Best Student Platform. Go team Jeffries! (April 2016)

Meriel LeSueur receives two Honors College awards. Meriel, a Junior Biology major, was the recipient of a $1000 Honors College Undergraduate Research Award and a $1000 Honors College Scholar Award. Both awards will support Meriel's senior thesis project aimed at determining the impacts of thyroid hormone disruption on immune function and disease resistance. Congrats to Meriel! (April 2016)

Members of the Jeffries' Lab present their Senior Thesis Projects at the College of Science and Engineering Honors Symposium. Jacob Malmquist (Senior Biology major), Ali Medders (Senior Biology major), Elise Path (Senior Biology major), Kate Phillips (Senior Neuroscience major) and Kyle Roush (Senior Biology and Criminal Justice double major) presented the results of their Honors research projects to fulfill the requirements for Departmental Honors. Congrats to Jacob, Ali, Elise, Kate and Kyle on achieving this milestone! (April 2016)

Dr. Jeffries attends an international workshop on whole effluent toxicity testing in Paris, France. As an invited speaker at the Health and Environmental Sciences Institute workshop on “Concepts, Tools, and Strategies for Effluent Testing", Dr. Jeffries gave a presentation entitled "The FET for WET: Species comparisons, additional endpoints, and unforeseen obstacles" and co-chaired a breakout session on moving testing strategies from those that assess acute toxicity towards those that assess chronic toxicity. (March 2016)

Meriel LeSueur and Leah Thornton receive presentation award. During the 2016 Texas Chapter of the American Fisheries Society Meeting, Meriel LeSuer (a Junior Biology major) and Leah Thornton (MS in Biology, '15) received the Best Student Poster Presentation award for their poster entitled "Basic aspects of immunity in two teleost model organisms, the fathead minnow and the sheepshead minnow” which was presented at the 2015 TCAFS meeting in Tyler, TX. Congrats to Meriel and Leah! (January 2016)

Members of the Jeffries' lab attend the Texas Chapter of the American Fisheries Society Meeting. Kyle Roush, a senior double majoring in Biology and Criminal Justice, and Gunnar Nystrom, a Junior Biology and Business double major, attended the 2016 Texas Chapter of the American Fisheries Society (TCAFS) meeting in Kerrville, TX where they presented their research. Kyle presented a poster titled “Enhancing the fish embryo toxicity test: Growth, developmental abnormalities and gene expression as additional endpoints” co-authored by Julie Krzykwa (Biology MS student), Jacob Malmquist (Senior Biology major) and Dane Stephens (B.S. Biology, ’16). Gunnar presented his poster on “Biomonitoring of the Syr Darya River (Kazakhstan): Chemical contamination and biological effects”. While at the meeting, Gunnar received a Harry Tennison Scholarship provided by the Sportsmen’s Club of Fort Worth. Great job, Kyle and Gunnar! (January 2016)

Jeffries lab awarded grant for ecological monitoring of the Syr Darya River in Kazakhstan. Dr. Jeffries was awarded a $7,150 subcontract grant from Al-Farabi Kazakh National University to study the impacts of contaminants on fish populations in the Syr Darya River. The Syr Darya is one of two freshwater sources that feed the ecologically-stressed Aral Sea and the recovery of the Aral Sea is dependent upon the health of the Syr Darya watershed. The proposed project, which is a collaboration between US and Kazakh scientists, will evaluate the health of the Syr Darya River by assessing the presence and biological impacts of pesticides, heavy metals, radionuclides and other contaminants in the Syr Darya River. (August 2015)

Dr. Jeffries and Leah Thornton (MS student) travel to Kazakhstan for a workshop and pilot study on the ecotoxicology of the Syr Darya watershed. Dr. Jeffries and Leah attended a workshop entitled "Catalyzing New International Collaborations in Kazakhstan: Pesticide occurrence and ecological effects in the Syr Darya River Basin". As part of the workshop, Dr. Jeffries gave a presentation on " "Ecological Risk Assessment: A Framework for Assessing Pesticide Occurrence and Ecological Effects in the Syr Darya River Basin." Following the workshop, Dr. Jeffries and Leah, in collaboration with researchers from the University of Nebraska and Al-Farabi Kazakh National University, conducted a pilot study aimed at assessing the presence and biological effects of pesticides and heavy metals in the Syr Darya. (June 2015)

Dr. Jeffries and MS student, Leah Thornton, present three papers at the 18th Symposium on Pollutant Responses in Marine Organisms (PRIMO) in Trohdheim, Norway. Dr. Jeffries gave a platform presentation entitled “Exposures to PBDE-47 alter development and thyroid-related gene expression in two model organisms, Pimephales promelas and Xenopus laevis”, which was co-authored by Ally Yost (former BS student in Biology and Environmental Science, 2015) and Leah Thornton. A platform presentation entitled “Timing is everything: Exploring the differential effects of PBDE exposure in adult and early life stage fathead minnows”, was delivered by Leah and coauthored by TCU undergraduate students Elise Path (a Senior Biology major) and Gunnar Nystrom (a Junior Biology and Business double major). Leah also presented a poster on “Development of the fathead minnow as a model organism for immunotoxicity: Characterization of basic immune function parameters”, co-authored by current student Meriel LeSueur (a Junior Biology major) and former students Dane Stephens (BS in Biology, 2015) and Ally Yost. (May 2015)

Jeffries lab publishes article on the use of alternative strategies for assessing chemical and effluent toxicity in fish. Dr. Jeffries and Dane Stephens (former TCU student, BS in Biology, 2015) published an article in Environmental Toxicology and Chemistry entitled “The fish embryo toxicity test as a replacement for the larval growth and survival test: A comparison of test sensitivity and identification of alternative endpoints in zebrafish and fathead minnows” (Vol. 34, No. 6, June 2015, p. 1369-1381). The article presents data regarding a new toxicity testing method, the fathead minnow fish embryo test, which has been proposed as an alternative to toxicity tests that utilize larval fathead minnows. The full article can be viewed here. (May 2015)