1. Detection of a synthetic sex steroid in the American crocodile (Crocodylus acutus): Evidence for a novel environmental androgen
- Author
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Davinia B. Garrigós, Christopher M. Murray, Sergio Padilla, Craig Guyer, Michael Easter, Mahmood Sasa Marín, and Mark Merchant
- Subjects
Male ,0106 biological sciences ,0301 basic medicine ,Health, Toxicology and Mutagenesis ,Endocrine Disruptors ,Crocodile ,01 natural sciences ,Methyltestosterone ,Gonadal Steroid Hormones ,Alligators and Crocodiles ,education.field_of_study ,biology ,General Medicine ,Pollution ,Environmental androgen ,Androgens ,Female ,Steroids ,Environmental Monitoring ,Costa Rica ,medicine.medical_specialty ,Environmental Engineering ,food.ingredient ,597.987 286 Crocodilia (Cocodrilos) ,medicine.drug_class ,Population ,Crocodylus acutus ,Zoology ,010603 evolutionary biology ,Crocodylus ,03 medical and health sciences ,food ,Rivers ,biology.animal ,Yolk ,Internal medicine ,medicine ,Animals ,Environmental Chemistry ,education ,Sexual differentiation ,Public Health, Environmental and Occupational Health ,Estrogens ,General Chemistry ,Androgen ,biology.organism_classification ,United States ,030104 developmental biology ,Endocrinology ,Sex steroid ,Water Pollutants, Chemical ,Endocrine disrupting contaminants - Abstract
Endocrine-disrupting contaminants (EDC's) are well known to alter sexual differentiation among vertebrates via estrogenic effects during development, particularly in organisms characterized by temperature-dependent sex determination. However, substances producing androgenic effects typically lack potency when tested in laboratory settings and are virtually unstudied in field settings. Here, we assay levels of a synthetic androgen, 17a-methyltestosterone (MT), in a heavily male-biased population of American crocodiles in the Tempisque River Basin of Costa Rica based on the recent hypothesis that this chemical is an EDC in developing crocodilian embryos. The presence of MT was documented in all fieldcollected samples of egg yolk and in plasma of all age classes in among population of crocodiles. Hatchlings exhibited higher plasma MT concentrations (102.1 ± 82.8 ng/mL) than juveniles (33.8 ± 51.5) and adults (25.9 ± 20.8 ng/mL). Among populations, crocodiles captured in the Tempisque River (62.9 ± 73.7 ng/mL) were higher in MT concentration than those from Tarcoles (13.3 ± 11.4 ng/mL) and negative controls (0.001 ± 0.0002 ng/mL). A mechanism for the bio-transport of MT and its subsequent effects is proposed. Universidad de Costa Rica/[741-B5-270]/UCR/Costa Rica Organization for Tropical Studies/[OTS 507]/OTS/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP) UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiología
- Published
- 2017