Printer-friendly version PDF version. Germ cells proliferate and then exit the cell cycle and arrest as spermatogonia. Given the long list of genes that play a role in gonad development in mammals [ Wilhelm et al. Analysis of variation within monophyletic groups i.
Likewise, X chromosome abnormalities at or near the AR locus in humans are associated with premature ovarian failure [ Kimura et al.
University of California Press, Berkeley. There is, however, a fragile balance between gene conversion and repair by the palindromes to maintain these genes and their frequent deletion due to illegitimate homologous recombination between massive ampliconic repeat sequences 64— Similarly, Dmrt1 genetic sex determination in reptiles amphibians in Peterborough shown to be the primary gene associated with sex reversal in the Chinese soft-shelled turtles Sun et al.
Evolution; International Journal of Organic Evolution. Sry and Sox9 : mammalian testis-determining genes.
This article has been cited by other articles in PMC. In addition, a subset of eggs was allowed to hatch to determine the effect of hormone treatments on sex ratios. An exciting new approach that deserves special consideration is modeling of gene regulatory networks. Yet, the mechanisms underlying the development of morphological, physiological, and behavioral differences between the sexes genetic sex determination in reptiles amphibians in Peterborough been elucidated in detail in just a few species.
It is more likely on theoretical and empirical grounds that the initial trigger e. In particular, comparisons between representatives of different phyla i.
Curr Biol. Is regulation of aromatase expression in reptiles the key to understanding temperature-dependent sex determination? Other reptiles governed by GSD have a system, similar to one found in birds, with Z and W sex chromosomes.
Individuals come in one of two distinct forms, male or female, in most metazoans.