Geschlechtschromatin bei Lepidopteren

Occurence of sex chromatin is widespread amongLepidoptera. Somatic interphase nuclei of female larvae and adults contain a distinct heteropycnotic body which is missing in males. Two types of exceptions exist: one type in which heteropycnotic bodies not discernable from the sex chromatin in other species are formed in both sexes while in another type such chromatin bodies are absent in either sex. Absence of sex chromatin is not linked to a certain systematic entity within the Lepidoptera. In species possessing sex chromatin, the structural aspect of the heteropycnotic body varies within certain limits between different species and tissues. Chromosome analysis of 4 species, 3 of which exhibit normal chromatin bodies in females, while the 4th has no chromatin bodies in both sexes, agree with the interpretation of sex chromatin in the heterogametic females ofLepidoptera as a heteropycnotic Y-chromosome. This interpretation does not apply to those exceptional species which contain heteropycnotic bodies in both sexes.