INTERACTION OF THE T^10r MUTATION AND LETHAL t-HAPLOTYPES ON THE CHROMOSOME 17 OF THE MOUSE

Abstract

The short-tailed mutation (T^10r) induced by X-irradiation is allelic to the Brachyury (T) on chromosome 17 of the mouse. Embryos homozygous for the T^10r are arrested developmentally at an earlier stage than T/T embryos, but T^10r/T embryos are indistinguishable from the T/T. Serological studies suggest that the T^10r for may be a deletion. The present study examined genetic interaction of the T^10r and lethal t-haplotypes (t^w32, t¹, t^w5, t^w18, and t^w1). The T^10r/tⁿ heterozygotes gave rise to viable tailless mice. Therefore, the T^10r is similar to the T in interaction with recessive lethal t-haplotypes. Lethality factors of such t-haplotypes are mapped outside the abnormal region of T^10r.