SREL Reprint #3855

Transcriptional networks underlying a primary ovarian insufficiency disorder in alligators naturally exposed to EDCs

Matthew D. Hale1,2,3, Therese Koal4, Tuan Hai Pham4, John A. Bowden5, and Benjamin B. Parrott1,2

1Eugene P. Odum School of Ecology, University of Georgia, Athens, GA, USA
2Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA
3Department of Biology, University of Virginia, Charlottesville, VA, USA
4Biocrates Life Science Ag, Innsbruck, Austria
5Center for Environmental and Human Toxicology, Physiological Sciences, College of Veterinary Medicine,
University of Florida, Gainesville, FL, USA

Abstract: Interactions between the endocrine system and environmental contaminants are responsible for impairing reproductive development and function. Despite the taxonomic diversity of affected species and attendant complexity inherent to natural systems, the underlying signaling pathways and cellular consequences are mostly studied in lab models. To resolve the genetic and endocrine pathways that mediate affected ovarian function in organisms exposed to endocrine disrupting contaminants in their natural environments, we assessed broad-scale transcriptional and steroidogenic responses to exogenous gonadotropin stimulation in juvenile alligators (Alligator missippiensis) originating from a lake with well-documented pollution (Lake Apopka, FL) and a nearby reference site (Lake Woodruff, FL). We found that individuals from Lake Apopka are characterized by hyperandrogenism and display hyper-sensitive transcriptional responses to gonadotropin stimulation when compared to individuals from Lake Woodruff. Site-specific transcriptomic divergence appears to be driven by wholly distinct subsets of transcriptional regulators, indicating alterations to fundamental genetic pathways governing ovarian function. Consistent with broad-scale transcriptional differences, ovaries of Lake Apopka alligators displayed impediments to folliculogenesis, with larger germinal beds and decreased numbers of late-stage follicles. After resolving the ovarian transcriptome into clusters of co-expressed genes, most site-associated modules were correlated to ovarian follicule phenotypes across individuals. However, expression of two site-specific clusters were independent of ovarian cellular architecture and are hypothesized to represent alterations to cell-autonomous transcriptional programs. Collectively, our findings provide high resolution mapping of transcriptional patterns to specific reproductive function and advance our mechanistic understanding regarding impaired reproductive health in an established model of environmental endocrine disruption.

Keywords: Endocrine disruptors; Ovary; Alligator; Environmental health

SREL Reprint #3855

Hale, M. D., T. Koal, T. H. Pham, J. A. Bowden, and B. B. Parrott. 2022. Transcriptional networks underlying a primary ovarian insufficiency disorder in alligators naturally exposed to EDCs. Molecular and Cellular Endocrinology 557(111751).

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).