Meeting Abstract

P1.90  Wednesday, Jan. 4  Exploring genomic tools to sex non-sex chromosomal animal, American alligator (Alligator mississippiensis) COZ, J.H.*; DOHENY, B.M.; MCCOY, J.A.; RAINWATER, T.R.; BOGGS, A.S.P.; GUILLETTE, L.J.; College Of Charleston; Med. Uni. of SC/Hollings Marine Laboratory; Med. Uni. of SC/Hollings Marine Laboratory; Med. Uni. of SC/Hollings Marine Laboratory; Med. Uni. of SC/Hollings Marine Laboratory; Med. Uni. of SC/Hollings Marine Laboratory joeycoz@gmail.com

American alligators exhibit temperature dependent sex determination (TSD), by which sex is determined by egg incubation temperature. This makes them an excellent sentinel for studying the effects of endocrine disrupting chemicals (EDCs) on sex determination and reproductive system development. TSD can be overridden by estrogenic compounds or EDCs. One primary barrier to examining some of the endpoints of interest is that there is no minimally invasive way to sex hatchling alligators. This project examined whether the sex of adult alligators, of known sex, could be predicted by analyzing gene expression from samples of whole blood cells (BCs). Blood samples were collected from adult alligators at Yawkey Wildlife Refuge (Georgetown, SC) and mRNA was extracted from each sample of BCs. We selected four genes that are likely to be expressed in a sexually dimorphic fashion, including: aromatase (CYP19), estrogen receptor-1 (ESR1), estrogen receptor-2 (ESR2), and androgen receptor (AR). To test whether these genes are differentially expressed in males and females, we conducted quantitative real time reverse-transcription polymerase chain reaction (Q-PCR). We detected CYP19, ESR1, and AR mRNA in all samples, whereas we could not detect ESR2 mRNA. There were no statistically significant differences amongst the mRNA expression of CYP19, AR, and ESR1. These results, however, indicated that BCs could have steroidogenic function as well as receive sex steroid signals. This data suggest the BCs could be a target of EDCs that act through sex steroid receptors.