PLoS Biol. Sex chromosomes and reproductive anatomy of some intersexual marsupials. Here the authors show that the Y chromosome present in wild zebrafish was lost in laboratory strains and replaced by a new sex-determining system.
Piferrer, F. The degeneration of Y chromosomes. Here the sex chromosome mapping analysis and embryological experiments began to converge. Males are the homogametic sex ZZwhile females are the heterogametic sex ZW.
Kuroiwa, A. Genomes of Ellobius species provide insight into the evolutionary dynamics of mammalian sex chromosomes. In a female Boa constrictor that produced 22 female offspring in this manner was found in the wild. Hodgkin, J. Secondary sex characteristics Characteristics that usually follow primary sex determination of the testis or ovary, for example, colouration, musculature, genitalia and sex ducts.
Taking a genetic approach, groups began to whittle down the Y-chromosome looking for the testis-determining region called TDY in humans, or testis-determining factor, Tdf , in mice. A duplicated copy of dmrt1 in the sex-determining region of the Y chromosome of the medaka, Oryzias latipes.
Bull JJ Sex determination in reptiles.