Characterization Of Embryonic Reproductive Tract In Caiman Latirostris.

CANESINI G; GALOPPO G; LUQUE E.H.; MUÑOZ DE-TORO M; DURANDO M

Jornada; XVI JORNADAS DE LA SOCIEDAD ARGENTINA DE BIOLOGÍA "IMPACTO ANTRÓPICO SOBRE LA FISIOLOGÍA DE LOS ORGANISMOS"; 2014

Caiman latirostris exhibits temperature-dependent sex determination (TSD). Male-to-female sex reversal after in ovo estrogen/xenoestrogen exposure was demonstrated. In stage 22 of embryonic development (at the beginning of the gonadal sex differentiation), we characterized the primitive reproductive tract of embryos obtained from eggs incubated at temperature producing males (TPM) or females (TPF) or at TPM+E2 (a dose of 17-estradiol -E2- that overrides the temperature effect was administered at stage 20). Estrogen receptor alpha (ER) and proliferative activity were assessed by IHC and the ductal epithelium height (DEH) was determined in trichromic stained sections. TPM and TPM+ E2 groups showed higher percentage of proliferating cells both in the primitive gonad as in the duct, compared to TPF. Moreover, ER protein trended to a higher expression in TPM. The DEH was not different between all studied embryos. Our results demonstrate that caiman embryonic gonad and duct are highly sensitive not only to temperature effect but E2 action allowing us to study the effect of xenoestrogen exposure on embryonic reproductive tract.