Formation of the sex chromatin by a single X-chromosome in liver cells of Rattus norvegicus

Sex chromatin of cone cells of human retina

Each retinal cone cell of the female contains a sex-chromatin body not present in coinparable material from the male. Therefore the lack of detectable "patch" formation in female heterozygotes for red color-blindness (as expected from the X-inactivation hypothesis) cannot be attributed to failure of Barr-body formation.

SEXUAL DIMORPHISM IN INTERPHASE NUCLEI OF THE LION, FELIS LEO

A sex difference is present in the structure of interphase nuclei of somatic cells in a variety of tissues of the lion. In the female, but not in the male, there is a special mass of chromatin, the sex chromatin, which stands out from the general particulate chromatin. In neurons the sex chromatin is usually located adjacent to the nucleolus, but in other cell types it nearly always lies against the inner surface of the nuclear membrane. The sex chromatin has the cytochemical properties of desoxypentose nucleic acid and is probably derived from heterochromatic regions of one of the X-chromosomes of the female's sex chromosome complex. A mass similar to the sex chromatin of females is rarely encountered in nuclei of males. The sexual dimorphism present in interphase nuclei of the lion is similar to that described previously in other carnivores and in primates.