[Chromosomal mapping of ld gene which causes congenital limb deformity syndrome in KM-ld mouse]

Fourteen biochemical marker loci and 61 SSLP loci in congenic strain C57BL/6.KM-ld were screened to determine the loci linkage to ld gene, an autosomal recessive mutant gene in KM mouse which causes congenital limb deformity in mouse by means of electrophoresis and PCR amplification. The result showed that ld gene linked to D2Mit30, D2Mit62 and D2Mit63. To locate ld gene more accurately on chromosome 2, 86 backcross offsprings (C57BL/6 x KM-ld) F1 x KM-ld were produced for linkage analysis. From the backcross progeny genomic DNAs were amplified for D2Mit13, D2Mit30, D2Mit62 and D2Mit63 loci in vitro. According to phenotypes, the linkage between the four SSLP loci and ld gene was analysed by calculating genetic distance, ld gene was located exactly on Chr. 2, 76cM, with distances of 25.58cM to D2Mit30, D2Mit62 and D2Mit63, of 31.39cM to D2Mit13.