Discriminative effects of male age on male recombination and Minute mutation frequencies in Drosophila ananassae.

Abstract

Using two strains of D. ananassae, male recombination and Minute mutation frequencies were assayed with regard to the age of the male parent. One of the strains, L8, was characterized by a progressive decrease in male recombination with increasing age of the male parent, while the other strain, E22, exhibited no such changes throughout seven two-day broods. The pattern of recombination frequency in chromosome 2 was parallel to that in chromosome 3 in each strain. It was concluded that the factors responsible for changes in male recombination with male age affect both chromosomes 2 and 3 in common. In contrast, the two strains were similar in their pattern of frequency changes in Minute mutations with increasing male age, with a peak in the 4th brood. Genetic systems regulating male crossing-over and Minute mutations are discussed.