Lab Members » Martyniuk Lab » College of Veterinary Medicine

The people that have worked, volunteered, and studied in the Martyniuk Lab – past and present. We build on their knowledge, dedication and hard work. We truly function as a team and are always looking for enthusiastic, curious, motivated individuals to join us!

Principle Investigator: Dr. Christopher Martyniuk

Xuefang! — Drs. Martyniuk and Liang in Inner Mongolia, China.

Graduate Students

Sheridan Wilkinson MS, PhD Student

Sheridan Wilkinson earned a B.S. in marine biology and an M.S. in biology, focusing on molecular biology, from the University of West Florida. Her research interests range from molecular ecology and endangered species conservation to ecotoxicology and epigenetics. As an undergraduate, she studied the phylogeography of the coquina clam Donax variabilis, for which the results of this research will hopefully be published this year, and environmental DNA habitat monitoring of the endangered Gulf and Alabama sturgeon and a critically endangered species of sawfish. Her master’s research focused on the epigenetic effects of plastic exposure on DNA, specifically looking at how nanoplastic exposure changed the genomic DNA methylation of cultured bluegill epithelial cells. The manuscript for this research was published in February 2025.

Sheridan is now a 2nd-year PhD student in the Department of Physiology in the College of Veterinary Medicine. Her research focuses on how consumption of polyester microfibers affect the gut microbiome and immune function in bottlenose dolphins (Tursiops truncatus). She will also directly expose pinfish (Lagodon rhomboides) to environmentally relevant polyester microfiber levels to determine the systemic toxicological effects in the gut-brain-microbiota axis by observing changes in the gut microbiome and correlating them with neuroendocrine and lipidomic dysruptions in the brain. Her career goal is to perform her own research in ecotoxicology and molecular ecology of marine organisms, especially in the Gulf of America, as there are many unanswered questions regarding the fauna of this area. In her free time, Sheridan enjoys dancing, reading, weightlifting, geocaching, listening to music, and playing the guitar.

Piper Johnson, PhD Student

Piper Jamison Johnson graduated with a B.S. in Wildlife Ecology and Conservation from the University of Reno Nevada (UNR) in 2023. During her undergrad, she performed undergraduate research in a lab focused on animal physiological responses to changing environments. She was able to participate in a project revolving around the impacts of urbanization on the stress response of birds. It was through this work at UNR that she discovered her interest in studying animal physiology and how this research could aid in the conservation of wildlife species. After graduation, Piper spent time working at a wildlife rehabilitation hospital, gaining knowledge and hands-on experience working with wildlife in need. Inspired by her time spent at the wildlife hospital, Piper decided she wanted to continue with research related to animal physiology and went on to pursue her master’s degree. She joined a lab at the University of Texas Rio Grande Valley (UTRGV) in the fall of 2024, focusing on the reproductive physiology and endocrinology of sea turtles. Her thesis focused on the reproductive biomarkers of two different populations of nesting green sea turtles. She also had the opportunity to work on multiple other projects related to sea turtle biology and conservation. She will graduate from UTRGV with her master’s degree in Ocean, Coastal, and Earth Sciences in the summer of 2026, before joining the Martyniuk lab at UF in the fall of 2026! In her free time, Piper enjoys baking, hiking, reading, and spending time with her friends, family, and cat.

Visiting Scholars

Evelyn Cecilia Lopez Gonzalez, PhD

Evelyn Lopez Gonzalez is a visiting research scholar from Argentina and an Assistant Researcher at CONICET. She received her B.Sc. in Biodiversity and Doctoral Degree in Veterinary Sciences from Universidad Nacional del Litoral. Her research focuses on physiological and molecular responses to environmental contaminants, with an emphasis on early-warning biomarkers of toxicity in aquatic and semi-aquatic vertebrates.

Her work integrates ecotoxicology and conservation biology, using reptile and fish models to investigate physiological and molecular responses to pesticides and emerging contaminants. She applies cellular and molecular approaches, including targeted gene expression analysis; primary cell culture; peripheral blood cells assays to evaluate cytotoxicity, genotoxicity, apoptosis; and cellular stress responses.

In the Martyniuk lab, her current research examines PFAS exposure in zebrafish to characterize neurobehavioral outcomes and associated molecular pathways. Her work advances mechanistic understanding of contaminant effects and supports the development of tools for environmental monitoring and risk assessment.

Amany Sultan MS, PhD, Visiting Scholar

Dr. Sultan is a visiting scholar from Egypt who completed her MS and PhD degrees in toxicology. Dr. Sultan completed a Master’s degree on the toxicological effects of synthetic testosterone (Boldenone undecylenate). In her PhD she studied Curcuma longa as a natural herb for protection against insecticide mixtures (organophosphate insecticide fenitrothion and the pyrethroid deltamethrin). Now, Dr. Sultan is working in the Martyniuk Lab with PFAS chemicals and investigating the neurobehavioral changes and molecular pathways using a zebrafish model. Her future professional goal is to become an expert in different branches of toxicology and advance my career. A broader goal that she is passionate about is to contribute to environmental sustainability and natural alternatives to synthetic products. When Dr. Sultan is not doing novel research she spends time with her family, cooking, walking in nature and traveling!

2023-2025

Mariana Zamponi

Mariana visited from Brazil to learn molecular research techniques such as RNA isolation and purification, primer design and validation, gene expression analysis using qPCR, and experimental design. Mariana will use her new skills to help her complete her Masters degree in Antillean manatee rehabilitation research.

2024

Isaac Konig

Isaac visited from Brazil and collaborated on zebrafish research with Nazish Iftikhar, Kit Souders, and Liz Brammer-Robbins. All pictured below.

2022

Nazish Iftikhar

Nazish visited from Pakistan and collaborated on zebrafish research with Isaac Konig, Kit Souders, and Liz Brammer-Robbins. All pictured below.

2022

DVM Students

Sarafina Mowe

I am a DVM Candidate of the Class of 2028 at the University of Florida College of Veterinary Medicine. I am working with the Martyniuk lab and assisting Sheridan Wilkinson in her research regarding how “Unveiling the toxicity of environmentally relevant concentrations of polyester microfibers in pinfish (Lagodon rhomboides): Dysregulation of the gut microbiome causes disturbances in the gut—brain—microbiota axis, lipidomic changes in the brain, and immune suppression.” I am interested in marine mammal medicine and sea turtle rehabilitation. After veterinary school, I plan on completing an internship and residency program in aquatic animal health. Outside of veterinary medicine, I love to surf, weightlift, and enjoy the outdoors with friends and family!

2025-Present

Abigail Smith

I am a DVM Candidate of the Class of 2028 at the University of Florida College of Veterinary Medicine. I am working with the Martyniuk lab through the Florida Veterinary Scholars Program for the summer of 2025 and am researching the effects of PFNA on zebrafish. I am interested in wildlife and aquatics medicine and conservation, and hope to one day work with the Fish & Wildlife Service at either the federal or state level. Outside of veterinary medicine, I enjoy doing photography, hiking, kayaking, and reading mystery novels.

2024-2025

Sasha Spada-O’Neill

I am a doctoral candidate at the University of Florida College of Veterinary Medicine and have joined the Martyniuk lab through the Florida Veterinary Scholars Program in 2023. I am a double gator and attended the University of Florida as an undergraduate where I was first exposed to research in the Animalia Lab. I have been working alongside principal investigators Dr. Martyniuk, Dr. Vulpe, and Dr. Estrada along with postdoc Dr. Noble to screen the efficacy of CRISPR/cas9 gene editing strategy to correct the pyruvate dehydrogenase kinase 4 mutation in canine fibroblasts, and eventually, in cardiomyocytes. If successful, CRISPR may be a viable therapy for patients with dilated cardiomyopathy. My long-term goal is to contribute to the development and innovation of veterinary medicine – to widen the scope of care for our pets.

2022-2023

Nirali Pathak

I am a 3rd year veterinary student (Class of 2025) at the University of Florida College of Veterinary Medicine. I am interested in Small Animal Medicine, especially surgery and internal medicine. After graduating from veterinary school, I plan on completing a small animal rotating internship and residency program in surgery or internal medicine. In the Summer of 2022, I worked in the Martyniuk Lab as a Florida Veterinary Scholar studying gene editing for Dilated Cardiomyopathy in Dobermans. I gained valuable experience during the summer and presented my findings at two conferences, coming in 1st place for the DVM Poster Competition at the UFCVM Phi Zeta Celebration! Outside of veterinary medicine, I love to read, draw and paint, travel, and spend time with friends and family.

2021-2022

Undergraduate Students

Gil Nadler

I recently graduated from the University of Florida in Spring 2026, where I earned a B.S. in Biology and a B.A. in Jewish Studies, and I hope to one day become a physician. I work under Sheridan Wilkinson studying the toxicological effects of environmentally relevant polyester microfiber exposure in pinfish (Lagodon rhomboides). Outside of the lab, I was involved with the FLMNH Vertebrate Paleontology Department, Center for Undergraduate Research Board (CURBS), and Phi Delta Epsilon. In my free time, I enjoy watching motorsports (F1 and WEC), hiking, kayaking, playing video games, and collecting vinyl records.

J. Vicente Li

I’m a third-year student majoring in psychology with a minor in chemistry on the Pre-Med track. After I graduate, I plan on applying to medical school so that I may pursue a career as a surgeon. Outside of school, I enjoy cooking, playing piano and guitar, weightlifting, sparring, reading, and traveling. I hope to learn a lot about zebrafish and the chemicals they’re exposed to in this lab.

Jacqueline Gutierrez

I am currently a second-year animal sciences major with a minor in pathogenesis on the pre-veterinary track. My upcoming research project for the CALS Honors Certificate Program will focus on the behavioral and genetic effects of PFAS chemicals on zebrafish embryos. Outside of the research lab, I am involved in various student organizations including serving on the executive board of Flipping the System, being a peer mentor to first-generation students through the Machen Florida Opportunity Scholars (MFOS) Program, holding a lead teacher’s assistant position for the Introduction to Animal Science Lab course, volunteering at the small animal hospital, and participating in the Emerging Scholars Program.

Arianna Paulson

I am a junior majoring in biochemistry, and my dream is to be a physician one day. In the lab, I am having a lot of fun right now learning from Katie and trying new things. Outside the lab, I love nature, and I lead adventure trips here at UF through UF Outdoor Adventures! I love hiking, running, swimming, biking, and fishing. I also adore animals, and I have a pet bunny and a pet turkey who I love very much.

Katie McDonnell

I am a fourth-year Health Science major applying to medical school after graduation to pursue my M.D. in Psychiatry. My work currently focuses on studying the neurotoxic effects of a widely prescribed antidepressant, bupropion hydrochloride (Wellbutrin), on the development of zebrafish models (Danio Rerio). Off-campus, I enjoy running on Gainesville’s nature trails, painting, and taking care of my home garden.

Lauren Gross

I am a second-year undergraduate student majoring in Philosophy on the Pre-Medical track. After completing my undergraduate degree, I plan to pursue a medical doctorate (MD). Currently, I am conducting research on the toxicity of PFAS, using zebrafish embryos as a model system. This project explores the compound’s developmental impact and behavioral effects through imaging, gene expression analysis, and behavioral assays. Outside of research, I am an equestrian, enjoy going on the boat, and spending time with family and friends.

Hailey Skaggs

I am a second-year student majoring in Biochemistry with a minor in Sociology on the Pre-Medical track. Following the completion of an undergraduate education, I plan to pursue an M.D. as I have had a long-pursued dream of becoming a surgeon. The research I partake in is focused on the impact of environmental effects and various chemicals on the development of zebrafish larvae. Outside of research, I am involved in various student-run organizations around the UF campus, like Girls Empowered by Math and Science, Delta Delta Delta St. Jude Philanthropy Chair, volunteering at Shands and Project Downtown, Dance Marathon, and I am a CLAS mentor.

Phyllis Wah

I am a 1st year animal science major with a specialization in animal biology. I am also planning on double minoring in chemistry and zoology. I am in pre-vet track and have been dreaming of becoming a wildlife surgeon since I was 4. I joined Dr. Martyniuk’s laboratory to use zebrafish as a model to investigate how environmental contaminants affect aquatic animals in Florida. Fun fact about me: I can speak 4 languages and I have been to 21 countries outside of America!!

Lev Avidan

I am currently a sophomore biology major on the pre-med track. Within the laboratory, I am studying the effects of PFAS on zebrafish (such as PFNA, PFESA, and PFUDA). Outside of the classroom, I am also a Patient Transporter at Shands, a Standardized Patient at the UFCOM, and an intern at the Alachua County Teen Court Program. Within my free time, some of my hobbies include working out, cooking, and maximizing credit card/airline reward points to fly for free.

Former Members

The Martyniuk lab has hosted several FVSP students over the years. Check out this CVM video on the program.

https://www.youtube.com/watch?v=ipJRGJEcYVM

Elizabeth Brammer-Robbins at a manatee health assessment

Dr. Elizabeth Brammer-Robbins

Elizabeth Brammer-Robbins’ research interests range from wildlife ecology and conservation to ecotoxicology and endocrine disruption. Her Masters research was focused on FL manatee reproductive physiology through measurement and analysis of plasma lipid and hormone composition and concentration. This research has been published in peer-reviewed journals and she hopes these data will move FL manatee reproductive physiology forward. Elizabeth also investigated the use of probiotic treatments to prevent outbreaks of a bacterial pathogen in the ornamental fish industry. This manuscript is in progress and will be submitted for publication this year!

Elizabeth just graduated with her Ph.D. from the Department of Physiology in the College of Vet Med. Her Ph.D. dissertation involved conservation physiology and ecotoxicology research in the FL manatee and pinfish. This photo was taken during an annual manatee health assessment under USGS permit. Elizabeth’s career goal is to investigate and develop solutions to reproductive challenges faced by threatened or endangered species through research at a zoological institute or governmental scientific agency, and she will begin a 2-year post doc at the Cincinnati Zoo working with CREW on their Polar Bear Signature Project in July 2026. Elizabeth spends her free time playing with her Australian shepherd, hanging out with friends, playing volleyball, and exploring FL nature!

Dr. Kit Souders

Kit’s research interests range from hypertension, mitochondrial bioenergetics, and zebrafish behavior, while his current projects include in vitro and in vivo xenobiotic and endogenous chemical exposures, followed by high throughput experiments to assess primarily mitochondrial and metabolic endpoints. These include a variety of microplate based assays, Seahorse Bioanalyzer-based metabolic profiling experiments, as well as behavioral zebrafish assays using a Daniovision observation chamber. Kit finds the discovery component of science to be particularly rewarding as well as the thought and care that goes into designing experiments and communicating results. Over the past 5 years he has contributed data to over 30 scientific publications and hopes to publish many more! In his free time, Kit likes to garden, draw, read, and play with his daughter, Miriam.

Some of our favorite “Kit-isms”:

“How significantly do tadpoles change?” “Just a tad” “Hop skip and a jump” “Toadily”
“Committee meetings, all I can say is that you’re more afraid of them than they are of you!”
“On your mind like meningitis”

Veronica Perez-Rodriguez

Veronica’s graduate work focused on studying pesticides and other drugs. Her work consisted on exposing zebrafish embryos at different life stages to determine the sub-lethal effects of chemicals during key phases of development. She obtained a B.S. in Biology Cum laude honors with distinction from the University of Florida in 2017, a Masters in Veterinary Medical Sciences with a concentration in Toxicology from the University of Florida in 2019 and is a DVM Candidate at UF CVM. Some honors or awards include: University of Florida International Center Certificate of Excellence 2018, VGSA Inman Student Travel Award, Graduate Student Council Student Travel Award, SETAC Student Travel Award, Graduate Student Research Symposium – 3rd place qualified to represent UF at Graduate Schools statewide Symposium. Her research interests include: Aquatic Toxicology, Fish Physiology, Ecotoxicogenomics, transcriptomics , Endocrine Disruption, Mitochondrial disruption. Congratulations on getting into Vet School, Veronica!!!

https://www.youtube.com/watch?v=gwa4bDlX-_w

David Dreier

David Dreier was a Ph.D. student co-supervised by Drs. Chris Martyniuk and Nancy Denslow at the University of Florida. He was a Graduate Research Fellow of the National Science Foundation, where his research focused on developing adverse outcome pathways for multiple stressors in fish. David was also a distinguished graduate of Baylor University, where he held a Greater Research Opportunity Fellowship with the United States Environmental Protection Agency. From this experience, David’s research also leveraged emerging high-throughput, omics-based methods to assess the effects of environmental contaminants on the environment. His research has won several awards, including the F. Ray Wilson II Award for Best Thesis in the Physical and Life Sciences at Baylor University and the Foster (Sonny) Mayer Best Ph.D. Platform Presentation at SETAC North America. David has also been an active SETAC member and has served on the Board of Directors as Chair of the North America Student Advisory Council (NASAC). In his free time, David enjoys trail running and playing the saxophone. Congratulations on getting a job at Syngenta, David!!!

Former Visiting Domestic & International Students

Visiting Research Scholars

Giovane Gomes Ferreira

Department of Environmental Engineering

School of Engineering of São Carlos

University of São Paulo, Brazil

Isaac Konig

I am a PhD student in agricultural chemistry in Brazil and a visiting scholar at Martyniuk Lab. My project aims to compare the toxicity of carvacrol, carvacryl acetate and fipronil using zebra fish as a model.

During my masters in health sciences, I applied sublethal concentrations of carvacryl acetate to control the reproduction of ticks. The experiments showed that a single chemical modification in the structure of carvacrol, a natural compound extracted from oregano, was able to considerably enhance its biocidal activity against ticks. My goal now is to evaluate the toxicity of carvacrol and its derivative and compare with a commercially available acaricide to determine whether or not the natural based compound is safe for field applications. I am learning new techniques and refining my research skills at Martyniuk Lab. In my free time, I am going to as many Christmas parties as possible =D I also like to listen to music and hang out with friends.

Nazish Iftikhar, 2021-2022

Institute of Environmental Sciences and Engineering,
School of Civil and Environmental Engineering,
National University of Sciences and Technology,
Sector H-12, Islamabad 44000, Pakistan

Shuo Wang, 2019-2020

State Environmental Protection Key Laboratory of
Wetland Ecology and Vegetation Restoration,
School of Environment,
Northeast Normal University,
Changchun, China

Chi Wei (Terry), 2019-2020

College of Fisheries
Huazhong Agricultural University
Habei Province, China

Yohana M. Velasco-Santamaria, DVM, MSc, PhD

Post-Doctoral Fulbright Scholar
Leader of Research Group in Aquatic and Environmental Biotechnology and Toxicology – BioTox
Coordinator of the Laboratory of Toxicology and Biotechnology
Coordinator of Nodo Llanos – Red Colombiana de Mujeres Científicas

Hebatallah Mahgoub, PhD, MVSc, BVSc

Post-Doctoral Fulbright Scholar
Pathology Department
Faculty of Veterinary Medicine
Mansoura University, Egypt

Tao Huang, 2018-2019

Northeast Normal University
Changchun, China

Lihua Yang (PhD), 2018-2019

Institute of Hydrobiology
Chinese Academy of Sciences
Wuhan, China

Xujia Zhang, 2018-2019

Fangjie Cao, 2017-2018

Ondřej Adamovský, 2016-2018

Xuefang Liang, 2017-2018

Ling Zhao (Linda), 2017-2018

Hua Qing, 2017-2018

Hong Wang, 2016-2017

Wendi Malphurs, Former Lab Manager

Nader El Ahmadie, Former Lab Manager

Jordan Schmidt, Former Lab Manager

2016 Dillon Da Fonte (Ph.D. student with collaborator Dr. Vance Trudeau). Thesis Research: Regulation of aromatase in goldfish radial glial cells by secretoneurin. Department of Biology, University of Ottawa, CAN.
2015 David Bertolatus (PhD with collaborator Dr. Alan Vajda). Thesis Research: Impacts of municipal effluent and chemistry in the fathead minnow. Department of Integrative Biology University of Colorado, Denver.
2015 Lei Xing (Ph.D. student with collaborator Dr. Vance Trudeau). Thesis Research: Regulation of aromatase in goldfish radial glial cells by dopamine. Department of Biology, University of Ottawa, CAN.
2015 Carla Paixao (Undergraduate student). Brazil Scientific Mobility Program of the Brazilian Government. The Institute of International Education (IIE) is the contractual administrative agency for this program.
2015 Patrijia Marjan (Ph.D. candidate with collaborator Dr. Mark Servos). Thesis Research: Emerging environmental stressors of anthropogenic origin in waste water effluent from the Grand River: Endocrine disruption in rainbow darter. Department of Biology, University of Waterloo, Ont., CAN
2015 Meghan Fuzzen (Ph.D. candidate with collaborator Dr. Mark Servos). Thesis Research: Determining the link between individual and population level effects of municipal wastewater effluent on rainbow darters. Department of Biology, University of Waterloo, Ont., CAN
2015 Sofía Enrigue Peñaloza (undergraduate student). Department of Biotechnology, Monterrey Institute of Technology and Higher Education, Mexico City.
2015 Mariana González Medina (undergraduate student). Faculty of Chemistry, National Autonomous University of Mexico, MX.
2013 Anny Berenisse Sánchez Garayzar (Ph.D. candidate). Thesis Research: Immunotoxic effects of the pesticide chlorothalonil in fish (Danio rerio) and crustaceans (Litopenaeus vannamei). Department of Ecotoxicology, Centro de Investigación en Alimentación y Desarrollo, A.C. MX.
2013 Mónica Ruiz Rosario (undergraduate student). Thesis Research: The effects of the polycyclic aromatic hydrocarbon phenanthrene on fathead minnow embryo survival and development. Department: Faculty of Chemistry, National Autonomous University of Mexico, MX.

Past Graduate Students

2019-2025 Elizabeth Brammer-Robbins (PhD student). Dissertation: Cellular and Molecular Mechanisms of Florida Red Tide (Karenia brevis) Brevetoxin Exposure in the Pinfish (Lagodon rhomboides) and Florida Manatee (Trichechus manatus)
2014-2018 David Dreier (PhD student) (co-supervised). Dissertation: Advancing Adverse Outcome Pathways for Mitochondrial Dysfunction and Multiple Stressors in Fish
2012-2017 Jennifer Loughery (PhD student, UNB) (supervised). Dissertation: Systems biology approach for studying the impacts of polycyclic aromatic hydrocarbons on fish: Implication for Canadian oil sands extraction
2014-2016 Kathleena Sarty (MSc Student, UNB) (co-supervised). Thesis: Zebrafish as an in vitro model for natural product chemistry
2013-2015 Rosalinda Kan (MSc Student, UNB) (supervised). Thesis: The effects of selenium on the metabolism of rainbow trout: Implications for environmental monitoring of metal mining.
2012-2015 Andrew Cowie (MSc Student, UNB) (supervised). Thesis: Exploitation of OMICS data using semantic automated discovery and integration (SADI) web services for fish toxicology.
2010-2014 Paulina Bahamonde (PhD student, UNB) (co-supervised). Dissertation: Molecular tools to study the impacts of municipal wastewater in the Grand River, Ontario
2010-2012 Anna Ornostay (MSc student) (supervised). Thesis: The effects of the ureic-based herbicide linuron in the fathead minnow.
2010-2012 Meghan Doyle (MSc student) (co-supervised). Thesis: The effects of ethinylestradiol (EE2) on molecular signalling cascades in the mummichog (Fundulus heteroclitus)