Lepidoptera, i.e. moths and butterflies, have a female heterogametic sex chromosome system, with most females having a WZ constitution while males are ZZ. Besides this predominant WZ/ZZ system, Z/ZZ, WZ1Z2/Z1Z1Z2Z2 and W1W2Z/ZZ systems also occur. Sex is determined by an unknown W-linked gene or genes in Bombyx mori, but by dosage-dependent and equally unknown Z-linked genes in all Z/ZZ species. The female-heterogametic sex chromosome system has been conserved for at least 180 milliion years in the phylogenetic branch that combines Lepidoptera and Trichoptera. The W chromosome, which is present in most lepidopteran species, was incorporated into the system much later, about 90-100 MYA. The Z chromosomes display conserved synteny, much like the Z in birds or the X in mammals. The W, on the other hand, is evolving rapidly. It is crammed with repetitive elements which appear to have a high turnover rate, but poor in or even devoid of protein-coding genes. It has frequently undergone fusion with autosomes or sporadically been lost altogether.
資源タイプ
学術雑誌論文
出版タイプ
Accepted Manuscript
権利情報
The original publication is available at www.springerlink.com
You are visitor 01402503 — GeezerVison does not store the pages you look up. Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.
Mendeley出力