Jill Jenkins is a Research Microbiologist at the USGS Wetland and Aquatic Research Center.
Jill Jenkins’ efforts emphasize the study of potential impacts of environmental stressors at the cellular and molecular levels. Her major areas of focus include biomarker development, endocrine disruption, genetics, and comparative immunology. Key laboratory biotechnologies she uses are photomicroscopy and flow cytometry. Primary cell types studied are blood and spermatozoa, and assays are tailored to the particular species requirements and hypotheses being addressed.
Jenkins specializes in the development and application of biomarkers; these are measures of variables that respond in quantifiable ways to changes in the environment. The choice of particular biomarkers at specific biological levels of organization (such as genetic, cellular, tissue, hormonal, and organismal levels) depends on the study at hand. Because molecular and biochemical responses of cells are preceded by chemical changes in nuclei, cytoplasm, membranes, and extracellular fluids, these responses can be diagnostic and contribute to an assessment of ecosystem health.
BACKGROUND
1991-1992: Postdoctoral Res.; Reproductive Genetics Labs, Dept. of Obstetrics and Gynecology, Univ. of TN, with Stephen Wachtel
Education and Certifications
Ph.D., Microbiology, Memphis State University, 1991
M.S., Microbiology and Biochemistry, Idaho State University, 1985
B.S., Biology, Rochester Institute of Technology, 1981
Science and Products
Outlining Potential Health Effects of Exposure to Critical Elements: From Chemical Structure to Adverse Outcome Pathways
Detecting Sublethal Effects of Harmful Algal Blooms in Mammalian and Avian Cells
Comparative Freshwater Fish Toxicity Testing of Antimycin A
Photomicroscopy and Flow Cytometry — Lafayette, Louisiana
Computer-Assisted Sperm Motion Analysis in Measuring Reproductive Effects in Bass
Studying Immune Responses in the American Kestrel (Falco sparverius)
Detecting Differences in Bacterial Metabolism in the Buffalo National River
A Website Tool for Predicting Triploidy in Larval Fish Spawns
Flow Cytometry Applied to the Animal Kingdom in Studies of Natural Resource Science
Determining the Ploidy and Resultant Reproductive Capability of Artificially Spawned and Wild Caught Asian Carp
Pollinator Germplasm as a Genetic Resource for Conservation
Use of a Sustained-Release Chemical Delivery Device in Assessing Effects of Systemic Insecticides
Motility of sperm from adult largemouth bass pond exposure to 17 alpha-ethinylestradiol or estrone-atrazine mixture (2018)
Microchemistry demographics and development data from wild caught black carp in the Mississippi River basin, 2011-18
Biomarkers of laboratory-exposed Northern Leopard frogs to neonicotinoids: DNA cell cycle, fragmentation, and genome size
Serum osmolality, cortisol, and protein in laboratory common carp (Cyprinus carpio)
Laboratory analysis assessing immune response after flame retardant exposure in American kestrels, Falco sparverius, through 21 days post-hatch
Characteristics of Bacteria and Water Quality along the Buffalo National River 2017-2018
Discerning innate immunity in American kestrels, Falco sparverius, through 21 days post-hatch
Gene expression and liver cell metabolism from Xenopus laevis tadpoles exposed to neonicotinoids
Ploidy and genome size estimates of artificially produced larval pallid sturgeon, Scaphirhynchus albus
Establishing a standard ploidy assessment method using grass carp from Ohio, 2015-2016
Sperm quality biomarkers complement reproductive and endocrine parameters in investigating environmental contaminants in common carp (Cyprinus carpio) from the Lake Mead National Recreation Area (1999-2006)
Juvenile African clawed frogs (Xenopus laevis) express growth, metamorphosis, mortality, gene expression, and metabolic changes when exposed to thiamethoxam and clothianidin
Establishment of baseline cytology metrics in nestling American kestrels (Falco sparverius): Immunomodulatory effects of the flame retardant isopropylated triarylphosphate isomers
Production of haploid gynogens to inform genomic resource development in the paleotetraploid pallid sturgeon (Scaphirhynchus albus)
Establishing genome sizes of focal fishery and aquaculture species along Baja California, Mexico
Derivation of cat embryonic stem-like cells from in vitro-produced blastocysts on homologous and heterologous feeder cells
Defensible standardized ploidy assessments for Grass Carp (Ctenopharyngodon idella, Cyprinidae) intercepted from the commercial supply chain
Assessing the risk of diploid grass carp Ctenopharyngodon idella in the certified triploid supply chain in Ohio
Sperm quality biomarkers complement reproductive and endocrine parameters in investigating environmental contaminants in common carp (Cyprinus carpio) from the Lake Mead National Recreation Area
An accurate method for measuring triploidy of larval fish spawns
A pilot study testing a natural and a synthetic Molluscicide for controlling invasive apple snails (Pomacea maculata)
Hyla chrysoscelis (Cope’s gray treefrog) x Hyla cinerea (green treefrog): putative natural hybrid
Novel associations between contaminant body burdens and biomarkers of reproductive condition in male Common Carp along multiple gradients of contaminant exposure in Lake Mead National Recreation Area, USA
Non-USGS Publications**
**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
Outlining Potential Health Effects of Exposure to Critical Elements: From Chemical Structure to Adverse Outcome Pathways
The Federal Government was charged with ensuring a reliable supply of critical minerals from within the U.S., and to further this policy in a safe and environmentally responsible manner by identifying new sources of critical elements. The objective of this research is to delineate anticipated adverse outcome pathways for the critical elements.Detecting Sublethal Effects of Harmful Algal Blooms in Mammalian and Avian Cells
USGS Researchers are collaborating to study avian and mammalian cells to detect sublethal toxin effects following exposure to harmful algal blooms.Comparative Freshwater Fish Toxicity Testing of Antimycin A
Researchers are investigating the influence of Antimycin A on Asian carp and non-target fishes by measuring the effects of a novel species-specific bait formulation.Photomicroscopy and Flow Cytometry — Lafayette, Louisiana
About the ResearchThe Environmental Health Program collaborates with microbiologists at the Photomicroscopy and Flow Cytometry Laboratory to develop and apply biomarkers to evaluate the potential impacts of environmental contaminants at the cellular and molecular levels. Because molecular and biochemical responses of cells are preceded by chemical changes in nuclei, cytoplasm, membranes, and...Computer-Assisted Sperm Motion Analysis in Measuring Reproductive Effects in Bass
The objective of this research is to assess the sensitivity of female and male LMB reproductive capabilities at the time of year when they are physiologically preparing for spawning season (also known as gonad recrudescence).Studying Immune Responses in the American Kestrel (Falco sparverius)
The objectives of this study are to (1) investigate whether the immune system will respond to chemical stressors, such as new flame retardant compounds, and (2) determine if such chemical stressors influence white blood cells (WBC) responses after exposure to a viral pathogen mimicking bird flu.Detecting Differences in Bacterial Metabolism in the Buffalo National River
Each year, the Buffalo National River (BUFF) attracts 1.6 million visitors, many of whom enjoy recreational water activities. Since 2013, a confined animal feeding operation (CAFO) for swine has been operating on Big Creek, a BUFF tributary.A Website Tool for Predicting Triploidy in Larval Fish Spawns
Differentiating diploids from triploids at the earliest life stage possible allows for a more efficient use of resources including production time and rearing space. Thus, a reliable flow cytometric (FCM) method has been developed to discriminate triploids from diploids at the larval stage. In order to help simplify the process of differentiating triploids from diploids, we propose a simple...Flow Cytometry Applied to the Animal Kingdom in Studies of Natural Resource Science
Flow cytometry is a technique for rapidly analyzing large numbers of animal cells using light-scattering, fluorescence, and absorbance measurements.Determining the Ploidy and Resultant Reproductive Capability of Artificially Spawned and Wild Caught Asian Carp
The invasive grass carp and black carp are artificially spawned to produce triploids, which means they have three sets of chromosomes and are sterile. WARC scientists invented an early ploidy prediction process for produced fry, and a post-mortem assessment method for carp caught either in the wild or sold and hauled live to other states.Pollinator Germplasm as a Genetic Resource for Conservation
Honey bee colony failure is primarily due to the infestation of mites and agricultural pesticides, including neonicotinoids. USGS researches the impacts these have on honey bee reproductive capabilities.Use of a Sustained-Release Chemical Delivery Device in Assessing Effects of Systemic Insecticides
Neonicotinoid insecticides the fastest growing insecticide worldwide - and may play a role in the declines of terrestrial and aquatic vertebrate species. - Data
Motility of sperm from adult largemouth bass pond exposure to 17 alpha-ethinylestradiol or estrone-atrazine mixture (2018)
Adult largemouth bass have been shown to be sensitive to induction of intersex in response to chronic estrogen exposures over a complete reproductive cycle. Late summer to fall is the period of early gonad recrudescence when spermatogenesis is beginning in preparation for the spawning season in the spring. Our objective was to assess in 2018 whether early gonad recrudescence was a period of sensitMicrochemistry demographics and development data from wild caught black carp in the Mississippi River basin, 2011-18
Data consists of ploidy, otolith stable isotope analysis and microchemistry, age, weight, sex, length and geolocation data from wild caught black carp (Mylopharyngodon piceus) captured in the Mississippi River basin from 2011 through 2018.Biomarkers of laboratory-exposed Northern Leopard frogs to neonicotinoids: DNA cell cycle, fragmentation, and genome size
Data were collected on whole blood DNA parameters including cell cycle, DNA fragmentation, and genome size obtained from Northern leopard frogs exposed to neonicotinoid insecticides in the laboratory. Data consist of flow cytometry files that were generated in the analysis of the frog blood.Serum osmolality, cortisol, and protein in laboratory common carp (Cyprinus carpio)
Common carp were placed into three treatment groups based on levels of induced stress in the laboratory setting. Measurements of common carp blood serum cortisol and serum protein were collected by spectrophotometry. Additionally, serum osmolality measurements were obtained by vapor pressure osmometry. Fish weights were taken at the time of blood collection.Laboratory analysis assessing immune response after flame retardant exposure in American kestrels, Falco sparverius, through 21 days post-hatch
Laboratory analysis of innate American kestrel, Falco sparverius, immune response after exposure to flame retardant, isopropylphenyl phosphate (ITP) through 21 days post hatch. Data consist of flow cytometry files that were generated in the analysis of white blood cells from kestrel blood. Thus, data are in standard format that allows files created by one type of acquisition hardware and softwareCharacteristics of Bacteria and Water Quality along the Buffalo National River 2017-2018
A National Park Service Partnership Program project was conducted in 2017 - 2019 on water quality parameters up-stream and downstream of a confined animal feeding operation on a Buffalo National River tributary (Big Creek). Monthly, over a period of 20 months, patterns of nutrients in water (nitrogen and phosphorus), periphyton (chlorophyll a and algal assemblages), and bacterial responses (viableDiscerning innate immunity in American kestrels, Falco sparverius, through 21 days post-hatch
Data consist of flow cytometry files that were generated in the analysis of white blood cells from kestrel blood. Thus, data are in standard format that allows files created by one type of acquisition hardware and software to be analyzed by any other type.Gene expression and liver cell metabolism from Xenopus laevis tadpoles exposed to neonicotinoids
Data were collected from Xenopus laevis tadpoles exposed to clothianidin and thiamethoxam in two concentrations each, 100 ppm and 20 ppm. Gene expression was generated from brains and livers, and liver cells provided metabolic activity data.Ploidy and genome size estimates of artificially produced larval pallid sturgeon, Scaphirhynchus albus
Data consist of flow cytometry files (.FCS) that were generated in the analysis of larval pallid sturgeon specimens. Nuclei from produced larval sturgeon somatic cells were analyzed using flow cytometry to estimate genome size and assign ploidy. Freshly collected rainbow trout (Oncorhynchus mykiss), largemouth bass (Micropterus salmoides), or pallid sturgeon blood were used as external controls, wEstablishing a standard ploidy assessment method using grass carp from Ohio, 2015-2016
In 2015-2016, the Ohio Division of Wildlife's undercover law enforcement purchased 1,200 grass carp (Ctenopharyngodon idella). Fish heads and eyeballs were sent overnight to U.S. Geological Survey Wetland and Aquatic Research Center for ploidy analysis. Field and laboratory standard operating procedures were established and followed. Fish lengths, fish weights, and eyeball weights were obtained frSperm quality biomarkers complement reproductive and endocrine parameters in investigating environmental contaminants in common carp (Cyprinus carpio) from the Lake Mead National Recreation Area (1999-2006)
Lake Mead National Recreational Area (LMNRA) serves as critical habitat for several federally listed species and supplies water for municipal, domestic, and agricultural use in the Southwestern U.S. Contaminant sources and concentrations vary among sub-basins within LMNRA. To investigate whether environmental contaminant exposure is associated with alterations in male common carp (Cyprinus carpio) - Multimedia
- Publications
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Juvenile African clawed frogs (Xenopus laevis) express growth, metamorphosis, mortality, gene expression, and metabolic changes when exposed to thiamethoxam and clothianidin
Neonicotinoids (NEO) represent the main class of insecticides currently in use, with thiamethoxam (THX) and clothianidin (CLO) primarily applied agriculturally. With few comprehensive studies having been performed with non-target amphibians, the aim was to investigate potential biomarker responses along an adverse outcome pathway of NEO exposure, whereby data were collected on multiple biologicalEstablishment of baseline cytology metrics in nestling American kestrels (Falco sparverius): Immunomodulatory effects of the flame retardant isopropylated triarylphosphate isomers
Avian populations must mount effective immune responses upon exposure to environmental stressors such as avian influenza and xenobiotics. Although multiple immune assays have been tested and applied to various avian species, antibody-mediated immune responses in non-model avian species are not commonly reported due to the lack of commercially available species-specific antibodies. The objectives oProduction of haploid gynogens to inform genomic resource development in the paleotetraploid pallid sturgeon (Scaphirhynchus albus)
Order Acipenseriformes (sturgeons and paddlefishes) is an ancient lineage of osteichthyan fishes (>200 million years old) with most extant species at conservation risk. A relatively basal species, the pallid sturgeon, Scaphirhynchus albus, is a federally endangered species native to the Mississippi and Missouri River basins. Hybridization with sympatric shovelnose sturgeon, S. platorynchus, is oneEstablishing genome sizes of focal fishery and aquaculture species along Baja California, Mexico
Genome size—the total haploid content of nuclear DNA— is constant in all cells in individuals within a species, but differs among species. Consequently, the genome size is a quantifiable genetic signature that not only characterizes a species, but it can reflect chromatin modifications, which play fundamental roles in most biological processes that are involved in the manipulation and expression oDerivation of cat embryonic stem-like cells from in vitro-produced blastocysts on homologous and heterologous feeder cells
The domestic cat is a focal mammalian species that is used as a model for developing assisted reproductive technologies for preserving endangered cats and for studying human diseases. The generation of stable characterized cat embryonic stem cells (ESC) lines to use as donor nuclei may help to improve the efficiency of interspecies somatic cell nuclear transfer for preserving endangered cats and aDefensible standardized ploidy assessments for Grass Carp (Ctenopharyngodon idella, Cyprinidae) intercepted from the commercial supply chain
Although methods are in place through the U.S. Fish and Wildlife (USFWS) program for ploidy testing of feral caught Grass Carp (Ctenopharyngodon idella) and black carp (Mylopharyngodon piceus), no guidelines exist for carp hauled across state lines. Using 1200 Grass Carp purchased by undercover Ohio law enforcement during 2015–2016, we developed a standardized protocol for discriminating ploidy byAssessing the risk of diploid grass carp Ctenopharyngodon idella in the certified triploid supply chain in Ohio
Non-native grass carp (Ctenopharyngodon idella) have been stocked in the United States for vegetation control since the 1970s, and recent evidence suggests some natural reproduction in the Great Lakes basin. Despite all states and provinces bordering Lake Erie either banning grass carp or requiring imports of only sterile, U.S. Fish and Wildlife Service (USFWS)-certified triploids, the majority ofSperm quality biomarkers complement reproductive and endocrine parameters in investigating environmental contaminants in common carp (Cyprinus carpio) from the Lake Mead National Recreation Area
Lake Mead National Recreational Area (LMNRA) serves as critical habitat for several federally listed species and supplies water for municipal, domestic, and agricultural use in the Southwestern U.S. Contaminant sources and concentrations vary among the sub-basins within LMNRA. To investigate whether exposure to environmental contaminants is associated with alterations in male common carp (CyprinusAn accurate method for measuring triploidy of larval fish spawns
A standard flow cytometric protocol was developed for estimating triploid induction in batches of larval fish. Polyploid induction treatments are not guaranteed to be 100% efficient, thus the ability to quantify the proportion of triploid larvae generated by a particular treatment helps managers to stock high-percentage spawns and researchers to select treatments for efficient triploid induction.A pilot study testing a natural and a synthetic Molluscicide for controlling invasive apple snails (Pomacea maculata)
Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal®,Hyla chrysoscelis (Cope’s gray treefrog) x Hyla cinerea (green treefrog): putative natural hybrid
Naturally–occurring hybrid treefrogs have been occasionally found in the eastern United States. However, these hybrids are almost always between members of the same species group. On 10 Jun 2014, at 2145 h, we located an individual making an unusual advertisement call along Bayou Manual Road in Sherburne Wildlife Management Area in the Atchafalaya Basin of south-central Louisiana, USA, and broughtNovel associations between contaminant body burdens and biomarkers of reproductive condition in male Common Carp along multiple gradients of contaminant exposure in Lake Mead National Recreation Area, USA
Adult male Common Carp were sampled in 2007/08 over a full reproductive cycle at Lake Mead National Recreation Area. Sites sampled included a stream dominated by treated wastewater effluent, a lake basin receiving the streamflow, an upstream lake basin (reference), and a site below Hoover Dam. Individual body burdens for 252 contaminants were measured, and biological variables assessed included phNon-USGS Publications**
Jenkins, J.A. and D.D. Ourth. 1990. Membrane damage to Escherichia coli and bactericidal kinetics by the alternative complement pathway of channel catfish. Comparative Biochemisty and Physiology, 97B:477-481. http://www.ncbi.nlm.nih.gov/pubmed/2286064**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.