Dr. Cathy Richter is a Research Molecular Biologist at the Columbia Environmental Research Center.
Science and Products
Threatened, Endangered or Rare Species Detection
The non-invasive nature of eDNA methods for species detection is a great advantage for monitoring of rare, threatened, or endangered species.
Searching for Shiners in Missouri
Researchers from the University of Central Missouri (UCM), in collaboration with the Missouri Department of Conservation (MDC) and Columbia Environmental Research Center (CERC), implement environmental DNA (eDNA) methods to identify and manage Topeka Shiner populations in Missouri.
Molecular Section: eDNA Research
Environmental DNA (eDNA) research at CERC focuses on the development and utility of eDNA tools as well as interpretation of eDNA data in real-world management applications. We work with academic, state, federal and international partners in developing standards and best practices for eDNA technology and exploring the factors that affect eDNA detection in the field. Our lab's eDNA research covers...
Fishing and Hunting Integrated Science Team
The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...
Thiaminase activity measurements in whole zebrafish
Data describe results of a set of laboratory experiments using a previously described quantitative thiaminase I activity assay to test the thiaminase activity of whole zebrafish homogenates. Parameters described include the thiaminase activity data, dilution factors, incubation time, and tissue weight assayed. Experiments were conducted at the USGS Columbia Environmental Research Center, Columbia,
Water 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 mixtur
Physiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions.
Physiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions. Also included are water quality and chemical concentration data.
Polyacrylamide gel electrophoresis results with thiaminase activity stain of recombinant putative thiaminases expressed in E. coli
Data describe results of a set of laboratory experiments using polyacrylamide gel electrophoresis with a thiaminase activity stain to test the solubility and thiaminase activity of recombinant putative thiaminases expressed in E. coli. Parameters described include the presence and relative mobility of thiaminases, and the presence and relative mobility of recombinant proteins. Experiments were con
Longnose darter (Percina nasuta) eDNA survey results from the St. Francis River, Missouri 2018
Data describe a designed environmental DNA (eDNA) survey for the detection of longnose darter (Percina nasuta) in field collected water samples. Parameters described include the limit of detection and limit of quantification of the assay; a list of freshwater fish species tissue samples that were used to test specificity of the assay; and field collected water samples that were tested to detect th
Metabarcoding data from freshwater mussel eDNA collected in Clinch River, Virginia 2017
Data from metabarcoding assays to detect a suite of mussel species using mitochondrial DNA regions of the cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit (ND1) genes sequences.
Mucket eDNA detection in Wallen's Bend, Clinch river, Tennessee, September 2019
The data describe the technical performance of a designed qPCR assay for the detection of mucket (Actinonaias ligamentina) eDNA from field collected water samples. Parameters described include the sequences of the primers and probes used; the limit of detection and limit of quantification for the assay; a list of freshwater mussels species that were used to test specificity of the assay; and in si
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.
Asian carp eDNA and egg morphology data collected from Truman Reservoir tributaries, Missouri, USA, 2014
Ichthyoplankton tows samples collected from Truman reservoir tributaries evaluated for eDNA. Data also includes hydrologic and water quality parameters and morphology of grass carp eggs.
eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines_2015_2016
Geospatial locations of eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines
Filter Total Items: 37
Genetic 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 recruitm
Authors
Catherine A. Richter, Allison N. Evans, Scott A. Heppell, James L. Zajicek, Donald E. Tillitt
Declines 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-ethinylestrad
Authors
Jessica Kristin Leet, Catherine A. Richter, Robert Gale, Donald E. Tillitt, Jill Jenkins
Exposure 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) exposed
Authors
Jessica Kristin Leet, Justin Greer, Catherine A. Richter, Luke R. Iwanowicz, Edward Spinard, Jacquelyn McDonald, Carla M. Conway, Robert W. Gale, Donald E. Tillitt, John Hansen
Using structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA
Environmental (e)DNA tools are sensitive and cost-effective for early detection of invasive species. However, the uncertainty associated with the interpretation of positive eDNA detections makes it challenging to determine appropriate natural resource management responses. Multiple sources of error can give rise to positive detections of eDNA in a sample when individuals of that species are not pr
Authors
Adam J. Sepulveda, David R. Smith, Katherine M O'Donnell, Nathan Owens, Brittany White, Catherine A. Richter, Christopher M. Merkes, Skylar Wolf, Mike Rau, Matthew Neilson, Wesley Daniel, Christine E. Dumoulin, Margaret Hunter
A comparison of eDNA and visual survey methods for detection of longnose darter Percina nasuta in Missouri
The longnose darter Percina nasuta is a rare and cryptic fish that recently disappeared from much of its historic range. We developed and used an environmental DNA (eDNA) assay for longnose darter paired with visual surveys to better determine the species’ range and compare detection probability between sampling approaches in an occupancy modeling framework. We detected longnose darter eDNA furthe
Authors
Jacob Thomas Westhoff, Leah K. Berkman, Katy E. Klymus, Nathan Thompson, Catherine A. Richter
Grass carp reproduction in small tributaries of Truman Reservoir, Missouri: Implications for establishment in novel habitats
Substantial work has been conducted to estimate the river length required for recruitment of invasive Grass Carp Ctenopharyngodon idella and bigheaded carps (Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix); however, the distance upstream and size of stream required for spawning remain unclear. Adult Grass Carp are regularly captured in Harry S. Truman Reservoir, Missouri, alth
Authors
Cari-Ann Hayer, Michael F. Bayless, Catherine A. Richter, Amy E. George, Duane Chapman
Reproduction
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. Fre
Authors
Frederick W. Goetz, J. Ellen Marsden, Catherine A. Richter, Donald E. Tillitt, Shawn P. Sitar, Stephen Riley, Charles C. Krueger
Metabarcoding assays for the detection of freshwater mussels (Unionida) with environmental DNA
Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We develo
Authors
Katy E. Klymus, Catherine A. Richter, Nathan Thompson, Jo Ellen Hinck, Jess W. Jones
Development and testing of species-specific quantitative PCR assays for environmental DNA applications
New, non-invasive methods for detecting and monitoring species presence are being developed to aid in fisheries and wildlife conservation management. The use of environmental DNA (eDNA) samples for detecting macrobiota is one such group of methods that is rapidly becoming popular and being implemented in national management programs. Here we focus on the development of species-specific targeted as
Authors
Katy E. Klymus, Dannise Vannesa Ruiz Ramos, Nathan Thompson, Catherine A. Richter
Effects 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 c
Authors
Jessica 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. Tillitt
Use of environmental DNA to detect grass carp spawning events
The timing and location of spawning events are important data for managers seeking to control invasive grass carp populations. Ichthyoplankton tows for grass carp eggs and larvae can be used to detect spawning events; however, these samples can be highly debris-laden, and are expensive and laborious to process. An alternative method, environmental DNA (eDNA) technology, has proven effective in det
Authors
Cari-Ann Hayer, Michael F. Bayless, Amy E. George, Nathan Thompson, Catherine A. Richter, Duane Chapman
Reporting the limits of detection and quantification for environmental DNA assays
BackgroundEnvironmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully establis
Authors
Katy E. Klymus, Christopher M. Merkes, Michael J. Allison, Caren S. Goldberg, Caren C. Helbing, Margaret Hunter, Craig Jackson, Richard F. Lance, Anna M. Mangan, Emy M. Monroe, Antoinette J. Piaggio, Joel P. Stokdyk, Chris C. Wilson, Catherine A. Richter
Non-USGS Publications**
Taylor, J.A., Richter, C.A., Suzuki, A., Watanabe, H., Iguchi, T., Coser, K.R., Shioda, T., and vom Saal, F.S., 2012, Dose-related estrogen effects on gene expression in fetal mouse prostate mesenchymal cells: PLOS ONE, v. 7, no. 10, p. e48311
Taylor, J.A., Richter, C.A., Ruhlen, R.L., and vom Saal, F.S., 2011, Estrogenic environmental chemicals and drugs: Mechanisms for effects on the developing male urogenital system: The Journal of Steroid Biochemistry and Molecular Biology, v. 127, no. 1, p. 83-95
Richter, C.A., Taylor, J.A., Ruhlen, R.L., Welshons, W.V., and vom Saal, F.S., 2007, Estradiol and Bisphenol A stimulate androgen receptor and estrogen receptor gene expression in fetal mouse prostate mesenchyme cells: Environmental Health Perspectives, v. 115, no. 6, p. 902-908
vom Saal, F.S., Richter, C.A., Mao, J., and Welshons, W.V., 2005, Commercial animal feed: Variability in estrogenic activity and effects on body weight in mice: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 7, p. 474-475
Timms, B.G., Howdeshell, K.L., Barton, L., Bradley, S., Richter, C.A., and vom Saal, F.S., 2005, Estrogenic chemicals in plastic and oral contraceptives disrupt development of the fetal mouse prostate and urethra: Proceedings of the National Academy of Sciences of the United States of America, v. 102, no. 19, p. 7014-7019
Richter, C., Timms, B., and vom Saal, F., 2005, Prostate development: mechanisms for opposite effects of low and high doses of estrogenic chemicals, in Naz, R., ed., Endocrine Disruptors: Effects on Male and Female Reproductive Systems: New York, CRC Press, p. 379-410.
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., Timms, B.G., and Welshons, W.V., 2005, The importance of appropriate controls, animal feed, and animal models in interpreting results from low-dose studies of bisphenol A: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 3, p. 140-145
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., and Welshons, W.V., 2004, Disruption of laboratory experiments due to leaching of Bisphenol A from polycarbonate cages and bottles and uncontrolled variability in components of animal feed, in National Research Council, ed., The Development of Science-based Guidelines for Laboratory Animal Care: Proceedings of the November 2003 International Workshop: The National Academies Press, p. 65-69.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Threatened, Endangered or Rare Species Detection
The non-invasive nature of eDNA methods for species detection is a great advantage for monitoring of rare, threatened, or endangered species.Searching for Shiners in Missouri
Researchers from the University of Central Missouri (UCM), in collaboration with the Missouri Department of Conservation (MDC) and Columbia Environmental Research Center (CERC), implement environmental DNA (eDNA) methods to identify and manage Topeka Shiner populations in Missouri.Molecular Section: eDNA Research
Environmental DNA (eDNA) research at CERC focuses on the development and utility of eDNA tools as well as interpretation of eDNA data in real-world management applications. We work with academic, state, federal and international partners in developing standards and best practices for eDNA technology and exploring the factors that affect eDNA detection in the field. Our lab's eDNA research covers...Fishing and Hunting Integrated Science Team
The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing... - Data
Thiaminase activity measurements in whole zebrafish
Data describe results of a set of laboratory experiments using a previously described quantitative thiaminase I activity assay to test the thiaminase activity of whole zebrafish homogenates. Parameters described include the thiaminase activity data, dilution factors, incubation time, and tissue weight assayed. Experiments were conducted at the USGS Columbia Environmental Research Center, Columbia,Water 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 mixturPhysiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions.
Physiological and molecular endpoints observed in juvenile largemouth bass in response to an estrogen (17α-ethinylestradiol) and subsequently a bacterial challenge (Edwardsiella piscicida) exposure under laboratory conditions. Also included are water quality and chemical concentration data.Polyacrylamide gel electrophoresis results with thiaminase activity stain of recombinant putative thiaminases expressed in E. coli
Data describe results of a set of laboratory experiments using polyacrylamide gel electrophoresis with a thiaminase activity stain to test the solubility and thiaminase activity of recombinant putative thiaminases expressed in E. coli. Parameters described include the presence and relative mobility of thiaminases, and the presence and relative mobility of recombinant proteins. Experiments were conLongnose darter (Percina nasuta) eDNA survey results from the St. Francis River, Missouri 2018
Data describe a designed environmental DNA (eDNA) survey for the detection of longnose darter (Percina nasuta) in field collected water samples. Parameters described include the limit of detection and limit of quantification of the assay; a list of freshwater fish species tissue samples that were used to test specificity of the assay; and field collected water samples that were tested to detect thMetabarcoding data from freshwater mussel eDNA collected in Clinch River, Virginia 2017
Data from metabarcoding assays to detect a suite of mussel species using mitochondrial DNA regions of the cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit (ND1) genes sequences.Mucket eDNA detection in Wallen's Bend, Clinch river, Tennessee, September 2019
The data describe the technical performance of a designed qPCR assay for the detection of mucket (Actinonaias ligamentina) eDNA from field collected water samples. Parameters described include the sequences of the primers and probes used; the limit of detection and limit of quantification for the assay; a list of freshwater mussels species that were used to test specificity of the assay; and in siEffects 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.Asian carp eDNA and egg morphology data collected from Truman Reservoir tributaries, Missouri, USA, 2014
Ichthyoplankton tows samples collected from Truman reservoir tributaries evaluated for eDNA. Data also includes hydrologic and water quality parameters and morphology of grass carp eggs.eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines_2015_2016
Geospatial locations of eDNA sampling sites in the Grand Canyon region near breccia pipe uranium mines - Publications
Filter Total Items: 37
Genetic 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. 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 HansenUsing structured decision making to evaluate potential management responses to detection of dreissenid mussel (Dreissena spp.) environmental DNA
Environmental (e)DNA tools are sensitive and cost-effective for early detection of invasive species. However, the uncertainty associated with the interpretation of positive eDNA detections makes it challenging to determine appropriate natural resource management responses. Multiple sources of error can give rise to positive detections of eDNA in a sample when individuals of that species are not prAuthorsAdam J. Sepulveda, David R. Smith, Katherine M O'Donnell, Nathan Owens, Brittany White, Catherine A. Richter, Christopher M. Merkes, Skylar Wolf, Mike Rau, Matthew Neilson, Wesley Daniel, Christine E. Dumoulin, Margaret HunterA comparison of eDNA and visual survey methods for detection of longnose darter Percina nasuta in Missouri
The longnose darter Percina nasuta is a rare and cryptic fish that recently disappeared from much of its historic range. We developed and used an environmental DNA (eDNA) assay for longnose darter paired with visual surveys to better determine the species’ range and compare detection probability between sampling approaches in an occupancy modeling framework. We detected longnose darter eDNA furtheAuthorsJacob Thomas Westhoff, Leah K. Berkman, Katy E. Klymus, Nathan Thompson, Catherine A. RichterGrass carp reproduction in small tributaries of Truman Reservoir, Missouri: Implications for establishment in novel habitats
Substantial work has been conducted to estimate the river length required for recruitment of invasive Grass Carp Ctenopharyngodon idella and bigheaded carps (Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix); however, the distance upstream and size of stream required for spawning remain unclear. Adult Grass Carp are regularly captured in Harry S. Truman Reservoir, Missouri, althAuthorsCari-Ann Hayer, Michael F. Bayless, Catherine A. Richter, Amy E. George, Duane ChapmanReproduction
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. KruegerMetabarcoding assays for the detection of freshwater mussels (Unionida) with environmental DNA
Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We develoAuthorsKaty E. Klymus, Catherine A. Richter, Nathan Thompson, Jo Ellen Hinck, Jess W. JonesDevelopment and testing of species-specific quantitative PCR assays for environmental DNA applications
New, non-invasive methods for detecting and monitoring species presence are being developed to aid in fisheries and wildlife conservation management. The use of environmental DNA (eDNA) samples for detecting macrobiota is one such group of methods that is rapidly becoming popular and being implemented in national management programs. Here we focus on the development of species-specific targeted asAuthorsKaty E. Klymus, Dannise Vannesa Ruiz Ramos, Nathan Thompson, Catherine A. RichterEffects 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. TillittUse of environmental DNA to detect grass carp spawning events
The timing and location of spawning events are important data for managers seeking to control invasive grass carp populations. Ichthyoplankton tows for grass carp eggs and larvae can be used to detect spawning events; however, these samples can be highly debris-laden, and are expensive and laborious to process. An alternative method, environmental DNA (eDNA) technology, has proven effective in detAuthorsCari-Ann Hayer, Michael F. Bayless, Amy E. George, Nathan Thompson, Catherine A. Richter, Duane ChapmanReporting the limits of detection and quantification for environmental DNA assays
BackgroundEnvironmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully establisAuthorsKaty E. Klymus, Christopher M. Merkes, Michael J. Allison, Caren S. Goldberg, Caren C. Helbing, Margaret Hunter, Craig Jackson, Richard F. Lance, Anna M. Mangan, Emy M. Monroe, Antoinette J. Piaggio, Joel P. Stokdyk, Chris C. Wilson, Catherine A. RichterNon-USGS Publications**
Taylor, J.A., Richter, C.A., Suzuki, A., Watanabe, H., Iguchi, T., Coser, K.R., Shioda, T., and vom Saal, F.S., 2012, Dose-related estrogen effects on gene expression in fetal mouse prostate mesenchymal cells: PLOS ONE, v. 7, no. 10, p. e48311
Taylor, J.A., Richter, C.A., Ruhlen, R.L., and vom Saal, F.S., 2011, Estrogenic environmental chemicals and drugs: Mechanisms for effects on the developing male urogenital system: The Journal of Steroid Biochemistry and Molecular Biology, v. 127, no. 1, p. 83-95
Richter, C.A., Taylor, J.A., Ruhlen, R.L., Welshons, W.V., and vom Saal, F.S., 2007, Estradiol and Bisphenol A stimulate androgen receptor and estrogen receptor gene expression in fetal mouse prostate mesenchyme cells: Environmental Health Perspectives, v. 115, no. 6, p. 902-908vom Saal, F.S., Richter, C.A., Mao, J., and Welshons, W.V., 2005, Commercial animal feed: Variability in estrogenic activity and effects on body weight in mice: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 7, p. 474-475
Timms, B.G., Howdeshell, K.L., Barton, L., Bradley, S., Richter, C.A., and vom Saal, F.S., 2005, Estrogenic chemicals in plastic and oral contraceptives disrupt development of the fetal mouse prostate and urethra: Proceedings of the National Academy of Sciences of the United States of America, v. 102, no. 19, p. 7014-7019
Richter, C., Timms, B., and vom Saal, F., 2005, Prostate development: mechanisms for opposite effects of low and high doses of estrogenic chemicals, in Naz, R., ed., Endocrine Disruptors: Effects on Male and Female Reproductive Systems: New York, CRC Press, p. 379-410.
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., Timms, B.G., and Welshons, W.V., 2005, The importance of appropriate controls, animal feed, and animal models in interpreting results from low-dose studies of bisphenol A: Birth Defects Research Part A: Clinical and Molecular Teratology, v. 73, no. 3, p. 140-145
vom Saal, F.S., Richter, C.A., Ruhlen, R.R., Nagel, S.C., and Welshons, W.V., 2004, Disruption of laboratory experiments due to leaching of Bisphenol A from polycarbonate cages and bottles and uncontrolled variability in components of animal feed, in National Research Council, ed., The Development of Science-based Guidelines for Laboratory Animal Care: Proceedings of the November 2003 International Workshop: The National Academies Press, p. 65-69.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.