Haplotype analysis of intra-specific backcross curly-tail mice confirms the localization of ct to chromosome 4.

We have determined the order of a number of SSR and SSC polymorphic markers that map to distal mouse Chromosome (Chr) 4 and have used analysis of these markers in backcrosses designed to test the localization of the curly-tail (ct) mutation. We have confirmed that ct maps to this region, close to the locus D4Mit69. Our results also support the hypothesis that ct is a semidominant, rather than a recessive, mutation, since we have identified abnormal-tailed mice that are likely to be heterozygous at the ct locus. Finally, we examined Pax7 as a candidate gene for the ct mutation and found no evidence of protein sequence differences in ct compared with wild-type mice.