THE LOSS OF CENTROMERES FROM CHROMOSOMES OF AGED WOMEN

Abstract

Both aneuploid cells in mitosis and nondisjunction in meiosis increase with advancing age. The cause(s) of these phenomena remains unknown. A positive Cd-band refelcts the presence of a functioning centromere while a negative reaction is indicative of its inactivation or loss. The Cd-banding technique was applied to mitotic spreads obtained from 14 aged and 13 control females (peripheral blood culture). Of 6474 scored chromosomes from the aged women, 62 (0.96%) were Cd-negative; this was the case in 12 of 3861 (0.31%) chromosomes from the younger controls. The difference was highly significant (P < 0.001). About 60% of the 62 Cd-negative chromosomes from aged women belong to the C group. Chromosomes from 6 of the 14 aged females were additionally examined by either the C-band or the distamycin-DAPI [4'',6-diamidino-2-phenylindole] technique; of 2080 chromosomes, 13 (0.63%) showed premature separation of their centromeres (control: 7/5080, 0.14%). In aged women, the chromosomes tend to lose their Cd-positive material and the function of the centromere.