| Abstract: | Both aneuploid cells in mitosis and nondisjunction in meiosis increase with advancing age. The cause(s) of these phenomena remains unknown. Here, it was confirmed that a positive Cd-band reflects the presence of a functioning centromere while a negative reaction is indicative of its inactivation or loss. We applied the Cd-banding technique to mitotic spreads obtained from 14 aged and 13 control females (peripheral blood culture). Of 6,474 scored chromosomes from the aged women, 62(0.96%) were Cd-negative; this was the case in 12 of 3,861 (0.31%) chromosomes from the younger controls. The difference was highly significant (P less than .001). About 60% of the 62 Cd-negative chromosomes from aged women belong to the C group. Chromosomes from six of the 14 aged females were additionally examined by either the C-band or the distamycin-DAPI technique; of 2,080 chromosomes, 13 (0.63%) showed premature separation of their centromeres (control: 7/5, 080, 0.14%). Our findings suggest that in aged women, the chromosomes tend to lose their Cd-positive material and the function of the centromere. |
