Centromere separation sequence in aged women and men

The centromere separation sequence of 5 old women (mean age 80.4 years), and 5 old men (mean age 75.5 years) was determined. Five young females (mean age 26.0 years) and 5 young males (mean age 27.4 years) served as controls. In each case 50 randomly selected lymphocyte mitoses were analysed microscopically and from photographs. In the groups of the young controls and aged men, the centromere separation sequence was clearly non-random and corresponded to the "normal sequence" observed in several earlier studies. In aged women chromosomes X, 8 and 10 divided earlier, while chromosomes 2, 3, 5 and 18 somewhat later than usual, but the individual and averaged patterns did not conspicuously differ from the "normal sequence". The premature centromere division (PCD) of X was not correlated with X-aneuploidy, and seemed not to correspond to the "long acentric fragment" often described in old females.