Dr. Don Tillitt is a Research Toxicologist at the Columbia Environmental Research Center.
Don has been at the Columbia Environmental Research Center (CERC) since 1989, then part of the U.S. Fish and Wildlife Service. He leads research on the effects of chemicals on fish and wildlife, with an emphasis on reproduction and development in fish. His research interests focus on developmental effects of persistent chemicals in fish. Multiple levels of biological organization are generally evaluated in his research efforts, with endpoints consisting of molecular, biochemical, histology, and behavioral-level effects. Recent research projects in his laboratory include: 1) effects of PCBs and dioxins on development in sturgeon species; 2) causes and effects of thiamine (vitamin B1) deficiencies on Great Lakes salmonines; 3) effects of endocrine disrupting chemicals on sexual differentiation and gonad development in fish; and 4) transgenerational epigenetic effects on endocrine disrupting chemicals across vertebrate taxa. Don has served in a variety of capacities for the Society of Environmental Toxicology and Chemistry, currently serves as an Editor for Environmental Toxicology and Chemistry. Don has adjunct professor appointments in the Biological Sciences and the School of Natural Resources at the University of Missouri. He serves on graduate student advisory committees, offers guest lectures, and has taught Environmental Toxicology since 1992.
Professional Experience
2013-present Senior Scientist, USGS Columbia Environmental Research Center, Columbia, MO
1989-2012 Research Chemist, USGS Columbia Environmental Research Center, Columbia, MO
1983-1989 Graduate Assistant, Michigan State University, E. Lansing, MI
Education and Certifications
Ph.D. Environmental Toxicology, Michigan State University, 1989
M.S. Fisheries and Wildlife, Michigan State University, 1986
B.S. Ag. Biochemistry, Michigan State University, 1981
B.S. Fisheries and Wildlife, Michigan State University, 1981
Affiliations and Memberships*
2010-present Adjunct Professor, Division of Biological Sciences, University of Missouri, Columbia, MO
1991-present Adjunct Professor, Department of Fisheries and Wildlife, University of Missouri, Columbia, MO
1991-2010 Adjunct Professor, Biochemistry Department, University of Missouri, Columbia, MO
1983-present Society of Environmental Toxicology and Chemistry
American Fisheries Society (lifetime member)
International Association of Great Lakes Research (lifetime member)
Science and Products
Thiamine (Vitamin B1) Deficiency in Fish and Wildlife
Disaster Science
Alternative complement pathway assay data for adult largemouth bass exposed in outdoor ponds to 17alpha-ethinylestradiol or an estrone-atrazine mixture
Egg thiamine content, length, weight and survival of steelhead (Oncorhynchus mykiss) exposed to three methods of experimental thiamine supplementation in 2022 and egg thiamine content from three Oregon hatcheries in 2019
Quantitation of estrogens in water, alone and in combination with atrazine, using two chemically-activated luciferase expression, CALUX, bioassays and quadrupole-time of flight ultraperformance liquid chromatography/mass spectrometry, UPLC-MS
Water chemistry and fish metrics data for adult largemouth bass exposed in outdoor ponds to 17alpha-ethinylestradiol or an estrone-atrazine mixture
Dissolved organic carbon, total petroleum hydrocarbons and and toxicity assay results for Bemidji, MN (2018)
Baseline fish health metrics in at-risk habitats critical for pallid sturgeon (Scaphirhynchus albus) in the Upper Missouri River Basin and bull trout (Salvelinus confluentus) in the Flathead River, Montana, 2017-18
Thiamine concentrations in lake trout eggs collected from the Great Lakes in 2019-20
Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17a-ethinylestradiol)
USGS Great Lakes lake trout egg thiamine monitoring data release
Acute toxicity and clotting times of anticoagulant rodenticides to red-toothed (Odonus niger) and black (Melichthys niger) triggerfish, fathead minnow (Pimephales promelas), and largemouth bass (Micropterus salmoides)
Development of a dual luciferase-fluorescamine assay adapted to a 384 micro-well plate format-Data
Reevaluation of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalency factors for dioxin-like polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls for fishes
Factors influencing egg thiamine concentrations of Lake Ontario lake trout: 2019–2020
Thiamine supplementation improves survival and body condition of hatchery-reared steelhead (Oncorhynchus mykiss) in Oregon
Genetic basis of thiaminase I activity in a vertebrate, zebrafish Danio rerio
Comparison of two estrogen chemically activated luciferase expression cell bioassays to liquid chromatography–mass spectrometry for quantifying estrone in water samples
Declines in reproductive condition of male largemouth bass (Micropterus salmoides) following seasonal exposure to estrogenic endocrine-disrupting compounds
Exposure to 17α-ethinylestradiol results in differential susceptibility of largemouth bass (Micropterus salmoides) to bacterial infection
Response to Gard et al.'s (2021) Comments on the Critical Review “Polychlorinated Biphenyl Tissue-Concentration Thresholds for Survival, Growth, and Reproduction in Fish”
Reproduction
Ecological risk assessment of environmental stress and bioactive chemicals to riverine fish populations: An individual-based model of smallmouth bass Micropterus dolomieu
Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17α-ethinylestradiol)
Neonicotinoid insecticide concentrations in agricultural wetlands and associations with aquatic invertebrate communities
Science and Products
- Science
Thiamine (Vitamin B1) Deficiency in Fish and Wildlife
In the last few decades, thiamine deficiency has been observed in fish and wildlife in the Great Lakes, Alaska, Sweden and several other areas in North America and Europe. Thiamine is an essential vitamin needed for cell function. Thiamine deficiency has been linked to neurological disorders, immunosuppression, and lower reproductive viability. These disorders potentially reduce populations of...Disaster Science
Natural (coastal storms, wildfires, floods) and human-induced (structural failures, building collapse, oil, and/or chemical spills) disasters occur every year in the United States. Minimizing loss of human life and damages to personal property and infrastructure is the focus of most disaster response and preparedness activities by federal, state, and local communities. However, the potential for... - Data
Alternative complement pathway assay data for adult largemouth bass exposed in outdoor ponds to 17alpha-ethinylestradiol or an estrone-atrazine mixture
Alternative complement pathway assay data observed in adult largemouth bass plasma in response to an EE2 (17alpha-ethinylestradiol) or mixture of estrone and atrazine exposure under laboratory pond conditions, with associated fish identification information.Egg thiamine content, length, weight and survival of steelhead (Oncorhynchus mykiss) exposed to three methods of experimental thiamine supplementation in 2022 and egg thiamine content from three Oregon hatcheries in 2019
Early rearing of steelhead (Oncorhynchus mykiss) in Oregon hatcheries is often problematic; fry can become emaciated and die during the period between hatch and first feed. Thiamine (vitamin B1) deficiency has caused early mortality in salmonids; however, thiamine status of Oregon’s anadromous steelhead populations is currently unknown. We sampled eggs of 7-10 females during spawning from three OrQuantitation of estrogens in water, alone and in combination with atrazine, using two chemically-activated luciferase expression, CALUX, bioassays and quadrupole-time of flight ultraperformance liquid chromatography/mass spectrometry, UPLC-MS
This data describes the relative luminescence units and relative fluorescence units of lysates of two estrogen responsive chemically-activated luciferase expression human breast VM7Luc4E2 and VM7LucERbc9 cells which were exposed for 24 hours to estrone and 17beta-estradiol dilutions alone and in mixture with atrazine or water extracts collected from dilutor tanks during a fish exposure study utiliWater chemistry and fish metrics data for adult largemouth bass exposed in outdoor ponds to 17alpha-ethinylestradiol or an estrone-atrazine mixture
Physiological endpoints observed in adult largemouth bass in response to an EE2 (17 alpha-ethinylestradiol) or mixture of estrone and atrazine exposure under laboratory pond conditions. Also included are water quality and chemical concentration data. Adult LMB were exposed in outdoor pond mesocosms from post-spawning to early gonad recrudescence to either EE2 (2.4 nanograms per liter), or a mixturDissolved organic carbon, total petroleum hydrocarbons and and toxicity assay results for Bemidji, MN (2018)
In crude-oil-contaminant plumes the dissolved organic carbon (DOC) is mainly hydrocarbon degradation intermediates only partly quantified by the diesel range total petroleum hydrocarbon (TPHd) method. To understand potential biological effects of degradation intermediates we tested three fractions of DOC: (1) solid phase extract (HLB); (2) dichloromethane (DCM-total) extract used in TPHd; and (3)Baseline fish health metrics in at-risk habitats critical for pallid sturgeon (Scaphirhynchus albus) in the Upper Missouri River Basin and bull trout (Salvelinus confluentus) in the Flathead River, Montana, 2017-18
Baseline fish health information on pallid sturgeon and bull trout or appropriate surrogate species (shovelnose sturgeon, cutthroat trout, mountain whitefish) in critical habitats with elevated risks of oil spills. Shovelnose sturgeon (Scaphirhynchus platorynchus) were collected in three locations near the confluence of the Missouri and Yellowstone Rivers and cutthroat trout (Oncorhynchus clarki lThiamine concentrations in lake trout eggs collected from the Great Lakes in 2019-20
Text files containing data regarding attributes of lake trout egg thiamine concentrations from sites in lakes Huron and Michigan collected during 2019-20, sampling site locations and quality assurance quality control values for comparison to previous years (2017-18) lake trout egg thiamine concentrations.Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17a-ethinylestradiol)
Largemouth base histological development and transcriptomic changes in gonad tissue after early life stage exposure to Atrazine (1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine) or the model estrogen 17a-ethinylestradiol.USGS Great Lakes lake trout egg thiamine monitoring data release
Monitoring of vitamin B1 (thiamine) in the eggs of lake trout (Salvelinus namaycush) collected from lakes Huron and Michigan has been conducted by the U.S. Geological Survey since the mid-1990?s. The results of this monitoring effort have been used by natural resource management agencies and native American tribes within the Great Lakes basin to evaluate the reproductive health of lake trout. TheAcute toxicity and clotting times of anticoagulant rodenticides to red-toothed (Odonus niger) and black (Melichthys niger) triggerfish, fathead minnow (Pimephales promelas), and largemouth bass (Micropterus salmoides)
Acute toxicity and clotting times of anticoagulant rodenticides of four fish speciesDevelopment of a dual luciferase-fluorescamine assay adapted to a 384 micro-well plate format-Data
We have adapted two commonly used human breast luciferase transactivation cell bioassays, the recently re-named estrogen agonist/antagonist screening VM7Luc4E2 cell bioassay (previously designated BG1Luc4E2) and the androgen/glucocorticoid screening MDA-kb2 cell bioassay, to 384-well formats for HTS of endocrine-active substances. This cost-saving adaptation includes a fast, accurate, and easy mea - Publications
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Reevaluation of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalency factors for dioxin-like polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls for fishes
An expert meeting was organized by the World Health Organization (WHO) in 1997 to streamline assessments of risk posed by mixtures of dioxin-like chemicals (DLCs) through development of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalency factors (TEFs) for mammals, birds, and fishes. No reevaluation has been performed for fish TEFs. Therefore, the objective of the present study was to rAuthorsJon A. Doering, Donald E. Tillitt, Steve WisemanFactors influencing egg thiamine concentrations of Lake Ontario lake trout: 2019–2020
In the Great Lakes region, thiamine deficiency is considered a recruitment bottleneck for lake trout Salvelinus namaycush and has been correlated with the consumption of non-native alewife Alosa pseudoharengus. While alewife, the most abundant forage fish in Lake Ontario, are the predominant prey for lake trout, they also consume benthic prey such as round goby Neogobius melanostomus. Because variAuthorsAaron Heisey, Christopher Osborne, Brian F. Lantry, Donald E. Tillitt, Jacques RinchardThiamine supplementation improves survival and body condition of hatchery-reared steelhead (Oncorhynchus mykiss) in Oregon
Early rearing of steelhead (Oncorhynchus mykiss) in Oregon hatcheries is often problematic; fry can become emaciated and die during the period between hatch and first feed. Thiamine (vitamin B1) deficiency has caused early mortality in salmonids; however, the thiamine status of Oregon’s steelhead populations is unknown, to date. Of the 26 egg samples from three Oregon hatcheries in 2019, 20 (77%)AuthorsAimee N. Reed, Freya Elizabeth Rowland, Jennifer A. Krajcik, Donald E. TillittGenetic basis of thiaminase I activity in a vertebrate, zebrafish Danio rerio
Thiamine (vitamin B1) metabolism is an important driver of human and animal health and ecological functioning. Some organisms, including species of ferns, mollusks, and fish, contain thiamine-degrading enzymes known as thiaminases, and consumption of these organisms can lead to thiamine deficiency in the consumer. Consumption of fish containing thiaminase has led to elevated mortality and recruitmAuthorsCatherine A. Richter, Allison N. Evans, Scott A. Heppell, James L. Zajicek, Donald E. TillittComparison of two estrogen chemically activated luciferase expression cell bioassays to liquid chromatography–mass spectrometry for quantifying estrone in water samples
Chemically activated luciferase expression (CALUX) cell bioassays are popular tools for assessing endocrine activity of chemicals such as certain environmental contaminants. Although activity equivalents can be obtained from CALUX analysis, directly comparing these equivalents to those obtained from analytical chemistry methods can be problematic because of the complexity of endocrine active pathwAuthorsJennifer C. Brennan, Abigail Henke, Robert Gale, Diane K. Nicks, Donald TillittDeclines in reproductive condition of male largemouth bass (Micropterus salmoides) following seasonal exposure to estrogenic endocrine-disrupting compounds
Reproductive abnormalities, that could lead to possible effects at the population level, have been observed in wild fish throughout the United States, with high prevalence in largemouth bass (LMB; Micropterus salmoides) and smallmouth bass (Micropterus dolomieu). Estrone (E1) and atrazine (ATR) are common environmental contaminants often associated with agricultural land use. 17alpha-ethinylestradAuthorsJessica Kristin Leet, Catherine A. Richter, Robert Gale, Donald E. Tillitt, Jill JenkinsExposure to 17α-ethinylestradiol results in differential susceptibility of largemouth bass (Micropterus salmoides) to bacterial infection
Disease outbreaks, skin lesions, mortality events, and reproductive abnormalities have been observed in wild populations of centrarchids. The presence of estrogenic endocrine disrupting compounds (EEDCs) has been implicated as a potential causal factor for these effects. The effects of prior EEDC exposure on immune response were examined in juvenile largemouth bass (Micropterus salmoides) exposedAuthorsJessica Kristin Leet, Justin Greer, Catherine A. Richter, Luke R. Iwanowicz, Edward Spinard, Jacquelyn McDonald, Carla M. Conway, Robert W. Gale, Donald E. Tillitt, John HansenResponse to Gard et al.'s (2021) Comments on the Critical Review “Polychlorinated Biphenyl Tissue-Concentration Thresholds for Survival, Growth, and Reproduction in Fish”
This response is offered to the critique by Gard et al. (2021) of our meta-analysis of polychlorinated biphenyl (PCB)-induced toxicity data in fish (Berninger and Tillitt 2019). Gard et al. (2021) offered numerous comments, the most substantive suggesting that 1) we should have added no-observable–adverse effect residue (NOAER) data from additional studies and all data points from selected studiesAuthorsJason P. Berninger, Donald E. TillittReproduction
Lake charr Salvelinus namaycush are typically fall spawners although one ecotype has populations that spawn during spring and fall (siscowets in Lake Superior). Lake charr are iteroparous (reproduce more than once in a lifetime) with group-synchronous ovarian development and typically spawn once per year. However, lake charr may not reproduce every year, a phenomenon known as skipped spawning. FreAuthorsFrederick W. Goetz, J. Ellen Marsden, Catherine A. Richter, Donald E. Tillitt, Shawn P. Sitar, Stephen Riley, Charles C. KruegerEcological risk assessment of environmental stress and bioactive chemicals to riverine fish populations: An individual-based model of smallmouth bass Micropterus dolomieu
Ecological risk assessments play an important role in environmental management and decision-making. Although empirical measurements of the effects of habitat changes and chemical exposure are often made at molecular and individual levels, environmental decision-making often requires the quantification of management-relevant, population-level outcomes. In this study, we generalized a modeling frameAuthorsYan Li, Vicki S. Blazer, Luke R. Iwanowicz, Megan K. Schall, Kelly Smalling, Donald E. Tillitt, Tyler WagnerEffects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17α-ethinylestradiol)
Endocrine disrupting contaminants are of continuing concern for potentially contributing to reproductive dysfunction in largemouth and smallmouth bass in the Chesapeake Bay watershed (CBW) and elsewhere. Exposures to atrazine (ATR) have been hypothesized to have estrogenic effects on vertebrate endocrine systems. The incidence of intersex in male smallmouth bass from some regions of CBW has been cAuthorsJessica Kristin Leet, Catherine A. Richter, Robert S. Cornman, Jason P. Berninger, Ramji K. Bhandari, Diane K. Nicks, James L. Zajicek, Vicki S. Blazer, Donald E. TillittNeonicotinoid insecticide concentrations in agricultural wetlands and associations with aquatic invertebrate communities
Neonicotinoids are considered a superior insecticide for agricultural pest management, although their impacts on non-target insects is a rising concern. Aside from laboratory and mesocosm studies, limited research has been directed towards the role neonicotinoids may have in structuring aquatic invertebrate communities in field settings. Therefore, we simultaneously collected aquatic invertebrateAuthorsT.J. Schepker, Elisabeth B. Webb, Donald E. Tillitt, T. LaGrange - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government