Biology 2485B Lecture Notes - Lecture 11: European Route E80, Androstane, Dehydroepiandrosterone
17 Dec 2015
School
Department
Course
Professor
Document Summary
Lecture 16 endocrinology 2: temperature-dependent sex determination. Sry sex-determining region on y chromosome. Once there are ovaries/testes, sexual differentiation depends on hormonal signals. Sex of the animal is determined by its chromosomes. This is the case for all mammals: xx and xy system. Small part of the embryo, the germinal ridge either develops into ovaries or testes. Expression of sry which leads to testes determination factor and testes development. Gnrh being secreted at a constant (tonic) level. In females, without sry we get ovary development they secrete gnrh cyclically, which is why we have monthly cycles. Z chromosome = primordial gonad" secretes estrogens. Proliferation of left gonad into ovary (most birds only have a left ovary, but paired testes) Overrides any male signals (e. g. from implanted tissue) Male copulation behaviour = default (takes estrogen treatment to get female behaviour, and treating females with aromatase inhibitors = male behavior) Birds only have one ovary, the left ovary.
