Resolution of sex chromosome constitution by genomic in situ hybridization and fluorescence in situ hybridization with (TTAGG) n telomeric probe in some species of Lepidoptera

摘要

Abstract We have developed a simple method to resolvethe sex chromosome constitution in females of Lepidopteraby using a combination of genomic in situ hybridization(GISH) and fluorescence in situ hybridization with(TTAGG)n telomeric probe (telomere-FISH). In pachyteneconfigurations of sex chromosomes, GISH differentiatedW heterochromatin and telomere-FISH detected the chromosomeends.With this method we showed that Antheraeayamamai has a standard system with a fully differentiatedW–Z sex chromosome pair. In Orgyia antiqua, we confirmedthe presence of neo-W and neo-Z chromosomes,which most probably originated by fusion of the ancestralW and Z with an autosome pair. In contrast to earlierdata, Orgyia thyellina females displayed a neo-ZW1W2sex chromosome constitution. A neo-WZ1Z2 trivalent wasfound in females of Samia cynthia subsp. indet., originatingfrom a population in Nagano, Japan. Whereas anothersubspecies collected in Sapporo, Japan, and determinedas S. cynthia walkeri, showed a neo-W/neo-Z bivalentsimilar to O. antiqua, and the subspecies S. cynthia ricinishowed a Z univalent (a Z/ZZ system). The combinationof GISH and telomere-FISH enabled us to acquire notonly reliable information about sex chromosome constitutionbut also an insight into sex chromosome evolutionin Lepidoptera.