Mechanism of infertility in t-complex mice

Abstract

Sperm from mice heterozygous (t/+) for many t-lethal haplotypes show segregation distortion. More offspring inherit the t-haplotype than the normal wild haplotype. In contrast males heterozygous (tx/tv) for two t-lethal haplotypes are sterile although they produce normal-looking sperm. The experiments were undertaken to show whether sperm from tx/tv mice are the same as t-fertile sperm from t/+. Female albino mice were persuaded to mate first with coloured sterile tx/tv heterozygotes and then with normal white +/+ males. With the exception of one litter (from a t-heterozygous male which proved to have been misidentified) all the progeny were derived from the mating with the normal father. We conclude that t-bearing sperm from t-lethal (tx/tv) heterozygotes are inviable, and different from t-sperm in t/+ heterozygotes.