Ageing and chromosome aberrations in male mammalian germ cells

The present observations have been performed on male mice from 30 to 750 days of age in order to elucidate whether the ageing process in male mammals is associated with an increased number of germ cells showing numerical or structural chromosome aberrations which could eventually be transmitted to the progeny. Cytological observations performed on dividing spermatocytes I showed that 76-83% of the cells appear normal, 2·8-5·0% are polyploid, 1·2-5·9% have autosomal univalents and 9·75-14·6% show X-Y univalents. No reciprocal translocation was observed in the dividing spermatocyte 1. The absence of evident relation between age and the incidence of anomalies suggests that the differences observed result of technical features.