The coding regions of the bovine and sheep skeletal muscleโspecific calpains (CANP3 or p94) were cloned and sequenced by RTโPCR. Direct sequencing confirmed open reading frames of 2466โbp for both species, and bovine and sheep CANP3 shared 98 ยท5% 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 twoโpoint LOD scores (โฅโ3 ยท0) and the best order was determined with multipoint linkage analysis (CRIโMAP vs. 2 ยท4). Bovine CANP3 mapped to bovine chromosome 10, relative position 33 ยท9โc
m with linkage to nine markers; LOD scores ranged from 4 ยท89 to 8 ยท61 (order, BMS2349โBL1035โRME25โCANP3โBM6305โBMS861โILSTS053โBMS2742โCA090โBMS529). Ovine CANP3 mapped to chromosome 7, relative position 58โc
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 ยท72. The observed heterozygosity was 50% for both CANP3 markers in bovine and sheep pedigrees.