title: Steroid signaling and temperature-dependent sex determination-Reviewing the evidence for early action of estrogen during ovarian determination in turtles.
abstract: The developmental processes underlying gonadal differentiation are conserved across vertebrates, but the triggers initiating these trajectories are extremely variable. The red-eared slider turtle (Trachemys scripta elegans) exhibits temperature-dependent sex determination (TSD), a system where incubation temperature during a temperature-sensitive period of development determines offspring sex. However, gonadal sex is sensitive to both temperature and hormones during this period-particularly estrogen. We present a model for temperature-based differences in aromatase expression as a critical step in ovarian determination. Localized estrogen production facilitates ovarian development while inhibiting male-specific gene expression. At male-producing temperatures aromatase is not upregulated, thereby allowing testis development.
authors.affiliation: Section of Integrative Biology, University of Texas, 2400 Speedway, Austin, TX 78712, United States.
authors.forename: Mary
authors.initials: M
authors.lastname: Ramsey
authors.forename: David
authors.initials: D
authors.lastname: Crews
mesh_terms: D000818:Animals; D001831:Body Temperature; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006066:Gonads / Q000166:cytology; D008297:Male; D010053:Ovary / Q000254:growth & development* / Q000378:metabolism; D012733:Sex Differentiation / Q000502:physiology*; D015398:Signal Transduction; D013256:Steroids / Q000378:metabolism*; D013696:Temperature; D014426:Turtles / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D004967:Estrogens; D013256:Steroids