Migration and linkage disequilibrium in local populations of the housefly (Musca domestica) in Japan

Abstract

Housefly populations in Hokkaido, Japan were examined. The frequency of females carrying a female-determining factor (F), which is epistatic to the male-determining factor (M), has been estimated to be very low. This means that most of the chromosomes carrying an M factor are transferred from male parents to their male progeny without recombination. Based on this characteristic situation, the association between theMfactor and one of the 6PGD alleles in Hokkaido in 1983 and 1984 was studied, and strong linkage disequilibrium was found in the samples from six spots in and around Sapporo. A specific allele, 6PGD¹, was associated in most of the cases with theMfactor-carrying third chromosome (III^M). The 6PGD locus was highly polymorphic in the M factor-free third chromosome (III). Based on these experimental results, it is suggested that the frequency of chromosome III^Mhas recently increased in the population around Sapporo.