CHROMOSOMAL SUBSTITUTION ANALYSIS OF RECEPTIVITY AND SEXUAL ISOLATIONIN DROSOPHILA-MELANOGASTER FEMALES

A chromosome substitution analysis was carried out in Drosophila melan ogaster to elucidate the contribution of the X, II and III chromosomes to female receptivity, and to sexual isolation with its sibling speci es D. simulans. Two lines from the same base population with extreme p henotypes, 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 a ffecting sexual isolation were located in all the three chromosomes. T hese results indicate that the direct relationship between female rece ptivity and sexual isolation previously detected in D. melanogaster co uld be because of the occurrence of genes common to the two traits in the chromosome III.