Genetic analysis of transmission ratio distortion by<i>t</i>-haplotypes in the mouse

Abstract

SUMMARY Lethal and semilethal t -haplotypes in the mouse are polymorphic in wild populations, where they are presumably maintained by transmission distortion from males, which transmit the aberrant chromosome to over 95% of progeny. We report here measurements of transmission ratio that show an unexpectedly strong effect of background genotype, specifically genes on the homologous chromosome, on the degree of transmission distortion of t -haplotypes. We also provide additional evidence that within t -haplotypes two separable elements co-operate to control transmission distortion, and that the system is thus closely analogous to segregation distortion in Drosophila, as has been previously proposed by Gluecksohn-Waelsch &amp; Erickson (1970), Demin, Safronova &amp; Lapkina (1978), and Styrna &amp; Klein (1982).