Sequence of centromere separation of mitotic chromosomes during human cellular aging

The sequence of centromere separation of mitotic chromosomes derived from lymphocytes of 17 individuals of various ages was studied. A comparison of the mean CSI (centromeric separation index) values for individual chromosomes in the complement indicated a significant difference between the older and the younger subjects only with regard to the chromosome nos. 6, 11, and 19 in both sexes and the X chromosome exclusively in the female. With age, chromosome no. 6 in both males and females and the X chromosome in females showed premature centromeric separation whereas chromosome nos. 11 and 19 in both males and females displayed delayed centromeric separation. Our study, therefore, indicates that changes in the sequence of centromeric separation of certain chromosomes do occur in lymphocytes during chronological aging in humans.