Such rapid turnover of sex chromosomes can occur by several mechanisms, including fusions between an existing sex chromosome and an autosome. Multiple sex chromosomes in the genus Hoplias Pisces: Erythrinidae Cytologia. Suzuki et al. The DMY gene spans six exons and encodes a putative protein of amino acids containing a DNA-binding domain called DM, which is also present in some proteins involved in sex determination in nematodes and flies.
Jpn J Ichthyol. Sex chromosomes and speciation in Drosophila. Although some taxonomic groups appear to have chromosomal sex determination in melandrium and fishes in Hervey Bay sex chromosomes that have been conserved across hundreds of millions of years of evolution, there are many examples of sex chromosome turnover, where even closely related species have different sex chromosomes White
Other H. In the Japan Sea form, cytogenetic studies and linkage analysis revealed that the X 1 X 2 Y system results from a fusion between an autosome chromosome 9 and the ancestral Y chromosome chromosome 19 Kitano et al. Polar Biol. Turnover of sex chromosomes induced by sexual conflict.
Reduced adaptation of a non-recombining neo-Y chromosome.
Support Center Support Center. Thus, the presence of genes with sexually antagonistic effects on an autosome might select for the evolution of a new sex-determination locus on that autosome, the transposition of an existing sex-determination locus to that autosome, or the fusion of that autosome to an existing sex chromosome.
PLoS Biol. Thorgaard ; Ueda and Ojima Dorsal spine length is sexually dimorphic in the Japan Sea population Kitano et al. In most mammalian species, the male-inducing master sex-determining gene, SRY , is located on the Y chromosome and is therefore absent from XX females.
Abstract Closely related species of fishes often have different sex chromosome systems.