title: Embryonic Atrazine Exposure Elicits Alterations in Genes Associated with Neuroendocrine Function in Adult Male Zebrafish.
abstract: The developmental origins of health and disease (DOHaD) hypothesis states that exposure to environmental stressors early in life can elicit genome and epigenome changes resulting in an increased susceptibility of a disease state during adulthood. Atrazine, a common agricultural herbicide used throughout the Midwestern United States, frequently contaminates potable water supplies and is a suspected endocrine disrupting chemical. In our previous studies, zebrafish was exposed to 0, 0.3, 3, or 30 parts per billion (μg/l) atrazine through embryogenesis, rinsed, and allowed to mature to adulthood. A decrease in spawning was observed with morphological alterations in offspring. In addition, adult females displayed an increase in ovarian progesterone and follicular atresia, alterations in levels of a serotonin metabolite and serotonin turnover in brain tissue, and transcriptome changes in brain and ovarian tissue supporting neuroendocrine alterations. As reproductive dysfunction is also influenced by males, this study assessed testes histology, hormone levels, and transcriptomic profiles of testes and brain tissue in the adult males. The embryonic atrazine exposure resulted in no alterations in body or testes weight, gonadosomatic index, testes histology, or levels of 11-ketotestosterone or testosterone. To further investigate potential alterations, transcriptomic profiles of adult male testes and brain tissue was completed. This analysis demonstrated alterations in genes associated with abnormal cell and neuronal growth and morphology; molecular transport, quantity, and production of steroid hormones; and neurotransmission with an emphasis on the hypothalamus-pituitary-adrenal and hypothalamus-pituitary-thyroid axes. Overall, this data indicate future studies should focus on additional neuroendocrine endpoints to determine potential functional impairments.
authors.affiliation: *School of Health Sciences, Purdue University, Indiana 47907.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Wirbisky
authors.affiliation: *School of Health Sciences, Purdue University, Indiana 47907 Department of Forestry and Natural Resources, Purdue University, Indiana 47907.
authors.forename: Maria S
authors.initials: MS
authors.lastname: Sepúlveda
authors.affiliation: *School of Health Sciences, Purdue University, Indiana 47907.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Weber
authors.affiliation: Bindley Bioscience Center, Purdue University, Indiana 47907.
authors.forename: Amber S
authors.initials: AS
authors.lastname: Jannasch
authors.affiliation: *School of Health Sciences, Purdue University, Indiana 47907.
authors.forename: Katharine A
authors.initials: KA
authors.lastname: Horzmann
authors.affiliation: *School of Health Sciences, Purdue University, Indiana 47907 jfreema@purdue.edu.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Freeman
mesh_terms: D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D052244:Endocrine Disruptors / Q000633:toxicity*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D006540:Herbicides / Q000633:toxicity*; D008297:Male; D009490:Neurosecretory Systems / Q000187:drug effects*; D060888:Real-Time Polymerase Chain Reaction; D013737:Testis / Q000187:drug effects / Q000378:metabolism; D059467:Transcriptome; D015027:Zebrafish / Q000196:embryology*
chemical_list: D052244:Endocrine Disruptors; D006540:Herbicides; D001280:Atrazine
keywords: atrazine; developmental origins of health and disease; hormones; neuroendocrine system; transcriptomics; zebrafish