SEX-REVERSED AND NORMAL TURTLES DISPLAY SIMILAR SEX STEROID PROFILES

In many oviparous reptiles, incubation temperature determines hatchlin g sex. Manipulation of the embryonic hormonal environment can result i n sex reversal. We measured circulating estradiol 17-beta (E(2)) and t estosterone (T) levels in temperature-determined and sex-reversed snap ping turtles (Chelydra serpentina). Eight-month-old turtles have sex s teroid profiles that are sex specific and are consistent with gonadal sex. Males had higher levels of T than females, both before and after treatment with follicle stimulating hormone (FSH). In males, T levels increased approximately 11-fold after FSH challenge, whereas in female s, T levels remained low In contrast, levels of E(2) after FSH challen ge were higher in females than in males, but showed no difference befo re treatment. Sex-reversed individuals appear to have normal sex stero id profiles of T and E(2), both at basal levels and in response to gon adotropin challenge. Our study indicates that the steroidogenic capabi lity of these juvenile turtles was consistent with gonadal morphology and suggests that these sex-reversed individuals have normal gonadal f unction. (C) 1996 Wiley-Liss, Inc.