Sex determination in mammals has been more extensively studied than in any other species, most probably due to its direct relevance to human physiology and pathophysiology. Exp Cell Res. Ramsey and Crews,
Graves4 Nicole Valenzuela2 Robert A. It turns out that ZZZ animals develop testes but are infertile, ZWW animals die early in embryonic development, but ZZW combinations manifest as intersexual: the animals appear female on hatching, but slowly turn into males at sexual maturity.
J Cell Biol. Cite molecular mechanisms of sex determination in reptiles and amphibians in Odessa How to cite? Eggs were collected and incubated as previously described [ Rhen et al. Figure 3. Nozu R, Nakamura M Cortisol administration induces sex change from ovary to testis in the protogynous wrasse, Halichoeres trimaculatus.
However, the differentiation of the embryonic testis does not also control all aspects of sex differentiation. A frequent alternative to GSD is environmentally triggered polyphenism i.
This category includes genes deriving from the various stages of X-Y gradual differentiation proposed by Page and described so far. Molecular mechanisms of sex determination in reptiles and amphibians in Odessa6 Jeffrey W. Trends Genet.
Ultrastructure des ebauches gonadiques du lezard vivipare Lacerta vivipara Jacquin pendant le periode de colonization par les gonocytes. We next explore whether this homology extends to the molecular level. Janzen F. Introduction Vertebrates show an astonishing array of mechanisms that govern sexual phenotype and so provide good models for exploring the evolution of sex-determining mechanisms.
A second stage in the formation of the X and Y is also attributed to a recombination failure, about — million years ago.
Extra care should be taken in the design of experimental controls when compounds developed for mammals are used in reptiles. The Evolution of Sex Determination. Mol Endocrinol.