Abstract
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, WZ 1Z 2/Z 1Z 1Z 2Z 2 and W 1W 2Z/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 MY in the phylogenetic branch that combines Lepidoptera and Trichoptera. The W chromosome, which is present in most lepidopteran species, was incorporated in the sex chromosome system much later, about 90-100 MY ago. The Z chromosomes are highly conserved among Lepidoptera, 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 lost altogether.
| Original language | English |
|---|---|
| Journal | Chromosome Research |
| Volume | 20 |
| Issue number | 1 |
| Pages (from-to) | 83-94 |
| Number of pages | 12 |
| ISSN | 0967-3849 |
| DOIs | |
| Publication status | Published - 01.01.2012 |
Funding
Acknowledgements We appreciate Magda Vítková’s (České Budějovice) kind supply of figures. The useful comments and suggestions from the anonymous reviewers are gratefully acknowledged. We thank Yasuhiro Yamada (Sapporo, Japan) for long-term technical assistance. K.S. received a Grants-in-Aid for Scientific Research (23380030) from Japan Society for the Promotion of Science.
