Gametic selection affecting sex-ratio in housefly (Musca domestica L.)

Abstract

An inheritable mechanism of sex-ratio distortion, causing a conspicuous, variable and unpredictable excess of males, has been recently observed in a field population of Musca domestica. The cause of this sex-ratio distortion, named Non-Mendelian-Sex-Ratio (NMSR), is always strictly associated with a male determinant on autosome 3 M III. NMRS causes a gametic selection, whereby the sperms carrying NMSR are advantaged during zygote formation. Therefore, the progeny consists mainly of males due to the association with MIII.Moreover, absence of crossing-over has been ascertained in females heterozygous for morphological markers of autosome 3 and carrying MIII and NMSR. This lack of recombination among NMSR, MIII and the markers of autosome 3 suggests that NMSR might be a true gene (NMSR), or the result of the pleiotropicgene action of a new MIII MIII-NMSR). © 1989 Taylor & Francis Group, LLC.