title: The transition in frequency of Y chromatin in males during the neonatal period.
abstract: The frequency of Y chromatin, visualized as fluorescent bodies in cell nuclei from lymphocytes in blood smears, was significantly less in newborn males than in three-month-old male infants and adults. The frequency of Y chromatin-positive cells on day 0 was 36.16 +/- 9.11% and then increased daily. At one month after birth the frequency was 55.07 +/- 9.29%, which was not significantly different from that in adult males (57.08 +/- 5.97%).
mesh_terms: D000328:Adult; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin; D003584:Cytological Techniques; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011796:Quinacrine; D012727:Sex Characteristics; D012730:Sex Chromosomes; D014998:Y Chromosome
chemical_list: D002843:Chromatin; D011796:Quinacrine