Back to Search Start Over

Methyltestosterone alters sex determination in the American alligator (Alligator mississippiensis)

Authors :
Mahmood Sasa Marín
Kelly A. Wilson
Michael Easter
Justin L. Rheubert
Thane Wibbels
Mark Merchant
Christopher M. Murray
Craig Guyer
Mary T. Mendonça
Amos Cooper
Source :
General and Comparative Endocrinology, vol. 236, pp. 63-69, Kérwá, Universidad de Costa Rica, instacron:UCR
Publication Year :
2016

Abstract

Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during adulthood. The organizational influence of endocrine-disrupting contaminants (EDC’s) produces a wide variety of reproductive abnormalities among vertebrates that exhibit temperature-dependent sex determination (TSD). Typically, such influences result in subsequent activational malfunction, some of which are beneficial in aquaculture. For example, 17-amethyltestosterone (MT), a synthetic androgen, is utilized in tilapia farming to bias sex ratio towards males because they are more profitable. A heavily male-biased hatchling sex ratio is reported from a crocodile population near one such tilapia operation in Guanacaste, Costa Rica. In this study we test the effects of MT on sexual differentiation in American alligators, which we used as a surrogate for all crocodilians. Experimentally, alligators were exposed to MT in ovo at standard ecotoxicological concentrations. Sexual differentiation was determined by examination of primary and secondary sex organs post hatching. We find that MT is capable of producing male embryos at temperatures known to produce females and demonstrate a dose-dependent gradient of masculinization. Embryonic exposure to MT results in hermaphroditic primary sex organs, delayed renal development and masculinization of the clitero-penis (CTP). UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)

Details

Language :
English
Database :
OpenAIRE
Journal :
General and Comparative Endocrinology, vol. 236, pp. 63-69, Kérwá, Universidad de Costa Rica, instacron:UCR
Accession number :
edsair.doi.dedup.....bfff6e97a79f4c61fc5516555edaabf9