76 Pages

F Mouse Genetics

The t "alleles" had an array of remarkable phenotypes. Aside from the interaction with T to cause taillessness, they caused homozygous lethality. Strangely, mice heterozygous for two different t alleles (tx!tY) had normal tails, but the males were invariably sterile. Furthermore, t alleles caused a strong recombination suppression in +It heterozygotes across a 20 centiMorgan (cM) region of proximal chromosome 17. Finally, and most startling, was that male mice heterozygous for a t haplotype (such as +!t or Tit) exhibited preferential transmission of the t allele to nearly all offspring.