Evidence for postmeiotic effect of t factors causing segregation distortion in mouse

THE t complex of the mouse consists of a large series of genetic factors often characterised by embryonic lethality of the homozygotes, reduced male fertility of viable homozygotes, suppression of recombination over a relatively long chromosomal segment and relatively frequent occurrence in natural mouse populations. Most t factors also possess a component which interacts with the Brachyury (T) gene and causes complete absence of the tail in T/t heterozygotes. One of the most fascinating but least explored characteristics of the t factors is their effect on genetic segregation. A male mouse carrying a t factor in a heterozygous condition (t/-) often transmits the factor to almost 100% of its progeny, in defiance of the Mendelian principle requiring 1:1 segregation.