title: Synergism between temperature and estradiol: a common pathway in turtle sex determination?
abstract: In many reptiles, the temperature at which the eggs are incubated determines the sex of the hatchlings. Administration of estradiol will counteract the masculinizing effects of a male-producing temperature, resulting in female hatchlings. To address whether temperature and estrogen are biologically equivalent, two experiments were conducted with the red-eared slider turtle, Trachemys scripta. In the first experiment, varying dosages of estrogen were administered at Stage 17 (the middle of the temperature-sensitive window) to eggs maintained at two temperatures, 26 degrees C (which normally produces all males) and 28.2 degrees C (which produces mostly males but lies at the threshold of the transition from male- to female-producing temperatures). Results indicate that estrogen and temperature exert a synergistic effect on sex determination. In the second experiment, estrogen was administered at different stages of embryonic development. The results indicate an estrogen-sensitive period ranging from Stage 14 through Stage 21, a period similar to the temperature-sensitive period for this species. The results of these experiments are consistent with the hypothesis that temperature and estradiol act in a common pathway in temperature-dependent sex determination.
authors.affiliation: Department of Zoology, University of Texas, Austin 78712.
authors.forename: T
authors.initials: T
authors.lastname: Wibbels
authors.forename: J J
authors.initials: JJ
authors.lastname: Bull
authors.forename: D
authors.initials: D
authors.lastname: Crews
mesh_terms: D000818:Animals; D004958:Estradiol / Q000502:physiology*; D005260:Female; D012732:Sex Determination Analysis; D013223:Statistics as Topic; D013696:Temperature; D014426:Turtles
chemical_list: D004958:Estradiol