Intra-nuclear sex dimorphism in the growing feathers of six species of galliformes.

Kosin and Ishizaki (1959) reported on the presence of a sex difference in the interphase nuclei of duodenal muscles and of both dermal and epidermal components of feathers in 3-week old chickens. A similar situation was also observed in the chicken blastoderms and amnion cells (Ishizaki and Kosin 1960). Ohno et al. (1960), Moore and Hay (1961), Azarova (1961), Takeuchi (1963), and Limborgh (1964) confirmed these findings for several types of tissues in mature chickens and chicken embryos. Furthermore, Limborgh (loc. cit.) observed a sex difference in the amnion cells of duck embryos, while Amanuma and Kosin (1964) presented affirmative evidence for the corresponding tissue of turkey and Coturnix quail embryos. The above data are contradicted by the negative results of Ashley and Theiss (1959), Miles and Storey (1962), and Hammar (1964), in their attempts to detect such dimorphism in cells from chicken embryos and mature donors. Similarly, negative evidence was reported over the years for several other avian species (Brusa 1952, Furieri 1958, Kang et al. 1963) as well as, again, Ashley and Theiss (loc. cit.) and Hammar (loc, cit.). In view of these contradictory reports, a re-examination of the question of nuclear sex difference in avian species was in order. The results obtained and the conclusions reached in the course of the study form the subject of the present paper.