Location of fourth chromosomal male-determining factors of the housefly, Musca domestica

Abstract

Two novel fourth chromosomal male-determining factors, IV^M, of the housefly were mapped using a modification of the general mapping procedure for autosomal male-determining factors, A^M (Inoue and Hiroyoshi 1984). On the basis of meiotic female recombination frequencies, the same gene order Barl-ye-M was demonstrated for the two IV^M chromosomes. On both chromosomes, male recombination took place although at exceedingly low frequencies. From a comparison between the female and the male recombination maps, it appears that, unlike other A^M factors examined so far, the two IV^M factors are not located near the centromere.