Sexing Study of Interphase Duodenum and Liver Nuclei in the Sixteen-Day Chick Embryo

Abstract

A study was made to confirm the existence of sex chromatin or some other sexual dimorphism in the interphase nuclei of the 16-day chick embryo. A Feulgen staining procedure was performed on sectioned epithelial tissues of the intestinal villi as well as sections and squashes of liver tissues. All chromatin masses, not just those suspected to represent sex chromatin, were recorded using a blind technique. The size, location and stain intensity of these chromatin masses were recorded, and seven different studies were made comparing male and female nuclei for sexual dimorphisms. No sex chromatin was found that resembled either that of mammalian nuclei or that described by previous authors working with chick material. The chromatin bodies, regardless of sex, varied greatly in size and number from one nucleus to another within a tissue. A sexual dimorphism, however, was observed. Statistical evidence showed that male nuclei have a greater number of large chromatin bodies, and a lesser number of small chromatin bodies than female nuclei.