Sex chromosome loss, micronuclei, sister chromatid exchange and aging: a study including 16 centenarians

In the present study we analysed the possible effect of age, sex and smokin g on the mean values of micronucleus (MN) and sister chromatid exchange (SC E) frequencies on peripheral blood obtained from 38 subjects ranging in age from 16 to 63 years and 16 centenarians. The mean number of binucleated ce lls with micronuclei varied in function of age and sex (as demonstrated by the analysis of covariance (F = 13.13; P < 0.001), particularly evident was the increment observed in women with increasing age (interaction age/sex: F = 5.53; P < 0.05). Smoking habits had no effects on MN frequency (F = 0.3 6; P > 0.05). Sex (F = 4.18; P < 0.05) and smoking habits (F = 14.64; P < 0 .001) influenced significantly SCE per cell frequencies, but age had no eff ects on them (F = 2.45; P < 0.05). The age-associated increase of sex chrom osome loss was studied using fluorescence in situ hybridisation (FISH) on i nterphase nuclei. The loss of Y signals was observed in similar to 10% of interphase cells fr om the centenarians males, that is six times more often than in the younger control men (similar to1.6%). The frequency of X signal loss (similar to1. 7%) in young women was similar to that observed in male controls of the sam e age but the incidence of the X chromosome aneuploidy in centenarian femal es was appreciably higher (similar to 22%) than that found for the Y chromo some in males. These results were correlated with the data on MN formation and a positive correlation between the percentage of aneuploid cells (FISH) and MN values was observed (r = 0.50; P < 0.05). (C) 2001 Published by Els evier Science B.V.