CHROMOSOMAL SUBSTITUTION ANALYSIS OF RECEPTIVITY AND SEXUAL ISOLATION IN DROSOPHILA-MELANOGASTER FEMALES

A chromosome substitution analysis was carried out in Drosophila melanogaster to elucidate the contribution of the X, II and III chromosomes to female receptivity, and to sexual isolation with its sibling species D. simulans. Two lines from the same base population with extreme phenotypes, the one showing high receptivity and weak isolation and the other showing low receptivity and strong isolation, were used. Genes involved in receptivity were located in chromosome III whereas those affecting sexual isolation were located in all the three chromosomes. These results indicate that the direct relationship between female receptivity and sexual isolation previously detected in D. melanogaster could be because of the occurrence of genes common to the two traits in the chromosome III.