Natalie Karouna-Renier, Ph.D.
Biography
Natalie is a Research Ecologist and leader of the Molecular Toxicology Laboratory at USGS Patuxent Wildlife Research Center. Her expertise and research focus on understanding, detecting, and predicting the effects of environmental stressors on wildlife using genomic, transcriptomic, metabolomic, endocrine, and biochemical tools. The lab specializes in identification and application of novel biomarkers for assessing ecosystem health.
Research Interests:
Current research projects in Natalie’s lab focus on immune system changes and susceptibility to disease in birds exposed to environmental contaminants; alterations in gut microbiomes and antibiotic resistance gene pools in birds exposed to urban and agricultural contaminants; hazard and toxicity of neonicotinoid pesticides to terrestrial species; and health status of wild birds exposed to contemporary contaminants (PFAS and novel flame retardants).
Education/Training:
- PhD in Biology from Rensselaer Polytechnic Institute, Troy, NY
- MS in Toxicology from the University of Maryland
- BS in Biology from Colgate University, Hamilton, NY
Science and Products
Immune System Changes and Susceptibility to Disease in Birds Exposed to Environmental Contaminants
Disease dynamics in wildlife are commonly related to changes or increases in environmental stressors that are placed upon an animal. Environmental pollutants are known to affect the immune system of wildlife, resulting in impaired resistance to infection and potential increases in disease outbreaks.
In collaboration with: Jill Jenkins, Ph.D USGS Wetland and Aquatic Research Center;...
Effects of Short Chain Chlorinated Paraffins (SCCPs) on developing birds
The Challenge: Short-Chain Chlorinated Paraffins (SCCPs) are complex technical mixtures of polychlorinated n-alkanes used in lubricants and coolants in metalworking, as flame retardants, and in paints, adhesives, sealants, textiles and polymeric materials, plastics and rubber. SCCPs are of concern because they are globally transported, bioaccumulate in wildlife and humans, and are...
Do pesticide coatings on agricultural seeds pose a threat to earthworms and to the birds that eat them?
Earthworms are a vital part of a healthy, functioning soil ecosystem and are also an important protein-rich food source for wildlife, including many species of birds and mammals. In an agricultural setting, the presence of earthworms can increase crop yields by 25%, but can also expose earthworms to pesticides. Seed treatment is the principal application method for neonicotinoid insecticides,...
Dysbiosis, immunomodulation, and health effects of agricultural pesticides in wild prairie grouse
Agrochemical pollution poses a severe threat to biodiversity. Agrochemicals can detrimentally affect wildlife growth, development, survival, reproduction, and immune responses, which facilitates emergence and spread of infectious diseases that may cause unusually high mortality. Animal microbiota plays a fundamental role in host’s food detoxification and defense against pathogens, regulates...
Contaminant Exposure, Food Web Transfer and Potential Health Effects on Chesapeake Bay and Delaware Bay Waterbirds
Chesapeake and Delaware Bays are the largest estuaries on the east coast of the United States. They support extensive fisheries and provide critical habitat for many species of wildlife. These Bays are surrounded by vast agricultural andindustrialized regions, with urbanized areas, all of which are a source of pollution that can affect natural resources. We have long monitored contaminants...
Immunomodulation Science Team
The Immunomodulation Integrated Science Team focuses on contaminant and pathogen exposures in the environment that might influence the immune systems of wildlife, livestock, and companion animals. In collaboration with public-health officials, the Team also addresses potential human-health risks stemming from similar exposures. If actual risks are identified, this Team will inform...
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.
Genomic and Behavioral Effects of the Neonicotinoid Imidacloprid in Birds Exposed Through Pesticide-Coated Seeds
The Challenge: Neonicotinoid pesticides act as agonists of nicotinic acetylcholine receptors (nAChRs) and are designed to be lethal to insects while theoretically posing little to no threat to vertebrates. The perceived safety of neonicotinoids has led to a sharp increase in their use in the United States and globally, since they were first introduced in 1994. The use of the neonicotinoid...
DNA Barcoding for Identifying Native Bee Species
The Challenge: Traditionally, bee identification has relied on taxonomic methods centered on descriptions of morphological differences between species. However, for many species, separate keys are required for identifying adult males and females and immature life stages. These keys are commonly unavailable. The lack of distinguishing morphological characters useful for separating closely...
Assessing Toxicogenomics Effects of a Synthetic Androgen on Japanese Quail and the Development of an Avian Vitellogenesis Model
The Challenge: Endocrine active chemicals (EAC) are known to interfere with hormonally regulated physiological processes, thereby affecting signaling in the hypothalamic-pituitary-gonadal-liver (HPGL) axis and commonly resulting in reproductive dysfunction. Computational models that relate hormonal and genomic biomarkers within the HPGL axis to the reproductive cycle and ecologically relevant...
The Role of Japanese Quail in Ecotoxicology
The Challenge: Wild birds are exposed throughout their lives to natural and synthetic chemicals that are present in the environment, many of which interfere with the animal’s physiological and developmental systems. Relative concentrations, routes, frequency, and the environment in which chemical exposure occurs will determine to a large extent the bird’s response. Well-designed avian field...
Identifying the Genetic Basis of Avian Susceptibility to Mercury
The Challenge: Mercury is a highly toxic element found throughout our environment. Although it occurs naturally in some environments, human industrial pollution has greatly increased the amount of mercury and the range of environments in which mercury is found. Recent studies have confirmed clear differences in the sensitivity of various bird species to methylmercury. Because the causes of...
Endocrine and physiological responses of hatchling American kestrels (Falco sparverius) following embryonic exposure to technical short-chain chlorinated paraffins (C10-13)
Short chain chlorinated paraffins (SCCPs) are complex mixtures of polychlorinated n-alkanes, shown to bioaccumulate but with unknown effects in wild birds. The present study examined development-related effects of SCCPs on captive American kestrels (Falco sparverius) treated in ovo on embryonic day (ED) 5 by injection with technical...
Fernie, Kim J.; Karouna-Renier, Natalie K.; Letcher, R. J.; Schultz, Sandra L.; Peters, L. E.; Palace, V.; Henry, Paula F. P. Legacy and contaminants of emerging concern (CECs) in tree swallows along an agricultural to industrial gradient: Maumee River, OH
Exposure to multiple classes of contaminants, both legacy and contaminants of emerging concern (CECs), were assessed in tree swallow (Tachycineta bicolor) tissue and diet samples from 6 sites along the Maumee River, Ohio, USA, to understand both exposure and possible effects of exposure to those CECs for which there are little avian data. The 6...
Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Schultz, Sandra L.; Tseng, Chi Yen; Karouna-Renier, Natalie K.; Matson, Cole W. Arsenic-related oxidative stress in experimentally dosed wild great tit nestlings
Arsenic (As) is broadly distributed due to natural and anthropogenic sources, and it may cause adverse effects in birds. However, research on other elements (Pb, Hg and Cd) has been prioritized, resulting in scarce data on As exposure and related effects in wild birds. One of the mechanisms responsible for As toxicity is oxidative stress....
Sánchez-Virosta, Pablo; Espín, Silvia; Ruiz, Sandra; Panda, Bineet; Ilmonen, Petteri; Schultz, Sandra L.; Karouna-Renier, Natalie K.; García-Fernández, Antonio J.; Eeva, Tapio Early life exposure to triphenyl phosphate: Effects on thyroid function, growth, and resting metabolic rate of Japanese quail (Coturnix japonica) chicks
Triphenyl phosphate (TPHP; CAS # 115-86-6), a commonly used plasticizer and flame retardant, has been reported in wild birds and identified as a potential high-risk chemical. We exposed Japanese quail (Coturnix japonica) by in ovo injection, and once hatched, orally each day for 5 days to safflower oil (controls) or TPHP dissolved in...
Guigueno, Melanie F.; Head, J.; Letcher, R.J.; Karouna-Renier, Natalie K.; Peters, Lisa; Hanas, A.M.; Fernie, K.J. In ovo exposure to brominated flame retardants Part II: Assessment of effects of TBBPA-BDBPE and BTBPE on hatching success, morphometric and physiological endpoints in American kestrels
Tetrabromobisphenol A bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTPBE) are both brominated flame retardants (BFRs) that have been detected in birds; however, their potential biological effects are largely unknown. We assessed the effects of embryonic exposure to TBBPA-BDBPE and BTBPE in a model avian...
Eng, Margaret; Karouna-Renier, Natalie K.; Henry, Paula F. P.; Letcher, Robert J.; Schultz, Sandra L.; Bean, Thomas G.; Peters, Lisa E.; Palace, Vince P.; Williams, Tony D.; Elliott, John E.; Fernie, Kim J. In ovo exposure to brominated flame retardants Part I: Assessment of effects of TBBPA-BDBPE on survival, morphometric and physiological endpoints in zebra finches
Tetrabromobisphenol A bis(2,3-dibromopropyl) ether (TBBPA-BDBPE) is an additive flame retardant used in polyolefins and polymers. It has been detected in biota, including in avian eggs, yet little is known of its effects. We assessed the pattern of TBBPA-BDBPE concentrations in songbird eggs over the incubation period, and the effects of embryonic...
Eng, Margaret; Williams, Tony D.; Fernie, Kim J.; Karouna-Renier, Natalie K.; Henry, Paula F. P.; Letcher, Robert J.; Elliott, John E. Perfluoroalkyl contaminant exposure in tree swallows nesting at Clarks Marsh, Oscoda, Michigan, USA
A site in north eastern Michigan, Oscoda Township, has some of the highest recorded exposure in birds to perfluorinated substances (PFASs) in the U.S. Some egg and plasma concentrations at that location exceeded the lowest reproductive effect threshold established for two avian laboratory species. The objectives of this study were to determine...
Custer, Christine M.; Custer, Thomas W.; Delaney, Robert; Dummer, Paul; Schultz, Sandra L.; Karouna-Renier, Natalie K. Toxicokinetics of imidacloprid-coated wheat seeds in Japanese quail (Coturnix japonica) and an evaluation of hazard
Birds are potentially exposed to neonicotinoid insecticides by ingestion of coated seeds during crop planting. Adult male Japanese quail were orally dosed with wheat seeds coated with an imidacloprid (IMI) formulation at either 0.9 mg/kg body weight (BW) or 2.7 mg/kg BW (~3 and 9% of IMI LD50 for Japanese quail, respectively) for 1 or 10 days....
Bean, Thomas G.; Gross, Michael S.; Karouna-Renier, Natalie K.; Henry, Paula F. P.; Schultz, Sandra L.; Hladik, Michelle; Kuivila, Kathryn; Rattner, Barnett A. Sex‐specific responses in neuroanatomy of hatchling American kestrels in response to embryonic exposure to the flame retardants bis(2‐ethylhexyl)‐2,3,4,5‐tetrabromophthalate and 2‐ethylhexyl‐2,3,4,5‐tetrabromobenzoate
Bis(2‐ethylhexyl)‐2,3,4,5‐tetrabromophthalate (BEH‐TEBP) and 2‐ethylhexyl‐2,3,4,5‐tetrabromobenzoate (EH‐TBB), flame retardant components of FireMaster 550® and 600® have been detected in tissues of wild birds. To address the paucity of information regarding potential impacts of flame retardants on the brain, brain volume regions of hatchling...
Guigueno, Mélanie F.; Karouna-Renier, Natalie K.; Henry, Paula F. P.; Peters, Lisa E.; Palace, Vince P.; Letcher, Robert J.; Fernie, Kim J. Female hatchling American kestrels have a larger hippocampus than males: A link with sexual size dimorphism?
The brain and underlying cognition may vary adaptively according to an organism’s ecology. As with all raptor species, adult American kestrels (Falco sparverius) are sexually dimorphic with females being larger than males. Related to this sexual dimorphism, kestrels display sex differences in hunting and migration, with females ranging more widely...
Guigueno, Melanie F.; Karouna-Renier, Natalie K.; Henry, Paula F. P.; Head, Jessica A.; Peters, Lisa E.; Palace, Vince P.; Letcher, Robert J.; Fernie, Kimberly J. Tributyltin: Advancing the science on assessing endocrine disruption with an unconventional endocrine-disrupting compound
Tributyltin (TBT) has been recognized as an endocrine disrupting chemical (EDC) for several decades. However, only in the last decade, was its primary endocrine mechanism of action (MeOA) elucidated—interactions with the nuclear retinoid-X receptor (RXR), peroxisome proliferator-activated receptor γ (PPARγ), and their heterodimers. This molecular...
Lagadic, Laurent; Katsiadaki, Ioanna; Biever, Ronald C.; Guiney, Patrick; Karouna-Renier, Natalie K.; Schwarz, Tamar; Meador, James P. Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District
Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining...
Beyer, W. Nelson; Casteel, Stan W.; Friedrichs, Kristen R.; Gramlich, Eric; Houseright, Ruth A.; Nichols, John W.; Karouna-Renier, Natalie K.; Kim, Dae Young; Rangen, Kathleen; Rattner, Barnett A.; Schultz, Sandra L.