Journal
GENERAL AND COMPARATIVE ENDOCRINOLOGY
Volume 129, Issue 3, Pages 171-177Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/S0016-6480(02)00530-0
Keywords
yolk; progesterone; testosterone; estradiol; red-eared slider; turtle; temperature-dependent sex determination
Categories
Ask authors/readers for more resources
This study investigates the potential effects of maternally derived hormones present in the yolk of reptile eggs. Specifically, we ask when are these hormones utilized by developing red-eared slider turtles (Trachemys scripta elegans), a species with temperature-dependent sex determination (TSD). Eggs were incubated at 27 degreesC, a male-producing temperature, and at 31 degreesC, a female-producing temperature. Concentrations of progesterone, testosterone. and 17beta-estradiol were measured at four points during development: at oviposition, at the start of the temperature sensitise period (TSP), at the end of the TSP, and at hatching. No effects of incubation temperature on yolk hormone concentrations were detected. The highest concentrations of all three hormones were measured at oviposition. Hormone-specific patterns of decline occurred throughout development. Each hormone declined between oviposition and the early TSP. Although estradiol was present in detectable quantities at oviposition, it was virtually undetectable by the early TSP. Testosterone showed no further decline after the early TSP. Progesterone continued to decline between the early and post-TSP. These results demonstrate that maternally derived yolk hormones decline at different rates. Alternative explanations for the disappearance of these yolk hormones are presented. (C) 2002 Elsevier Science (USA). All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available