Intra-Nuclear Sex Dimorphism in the Growing Feathers of Six Species of Galliformes

Abstract

The interphase nuclei of “stellate” pulp cells in the regenerating feathers of chickens, pheasants, turkeys, Japanese quail, guinea fowl, peafowl, ducks and White-crowned sparrows were examined for the existence of cytologically recognizable sex dimorphism. The cells were fixed in Davidson's fluid and subjected to Feulgen reaction.In all six Galliformes studied (chickens, pheasants, turkeys, guinea fowl, peafowl, and the Japanese quail), the frequency of nuclei carrying a characteristic heterochromatin, designated the sex-chromatin-like body or the scl body, was higher in females than in males i.e., 65% vs. 25% respectively, for the basal region of the feather and 50% vs. 15% for the distal. Both the size of the scl body and its affinity for the Feulgen reagent were greater in the female. These differences were statistically significant. In ducks and Whitecrowned sparrows, the frequency of the scl body, its size and affinity, although of a higher order of magnitude in females, were not significantly different from those in males.Lack of agreement in the literature on the existence of sex dimorphism in interphase avian nuclei was discussed in the light of the above results.