Molecular cloning and mapping of the bovine and ovine skeletal muscle‐specific calpains1

The coding regions of the bovine and sheep skeletal muscle-specific calpains (CANP3 or p94) were cloned and sequenced by RT-PCR. Direct sequencing confirmed open reading frames of 2466 bp for both species, and bovine and sheep CANP3 shared 98 ·5% identity in their amino acid code. These sequences were greater than 88% identical to human, pig, rat and mouse CANP3 nucleotide sequences, and greater than 93% identical for the amino acid code. Single nucleotide polymorphisms were used to map the bovine and sheep CANP3 genes in two steps. The genes were placed into linkage groups based on two-point LOD scores (≥ 3 ·0) and the best order was determined with multipoint linkage analysis (CRI-MAP vs. 2 ·4). Bovine CANP3 mapped to bovine chromosome 10, relative position 33 ·9 c m with linkage to nine markers; LOD scores ranged from 4 ·89 to 8 ·61 (order, BMS2349-BL1035-RME25-CANP3-BM6305-BMS861-ILSTS053-BMS2742-CA090-BMS529). Ovine CANP3 mapped to chromosome 7, relative position 58 c m, with linkage to only one marker, BMS861 (a bovine microsatellite that has been used in sheep), with no recombination and a LOD score of 5 ·72. The observed heterozygosity was 50% for both CANP3 markers in bovine and sheep pedigrees.