Calpains are the key proteases involved in muscle growth, protein transformation and meat tenderization. In this study, CAPN7 cDNA of Wild boar was cloned by RT-PCR, its sequence analysis, expression characterization and polymorphism analysis were performed. The results showed that the full-length coding sequence of Wild boar CAPN7 is 2442 bp long, and encodes a protein of 813 amino acids with the catalytic site of calpain family, whose catalytic triad residues is located at amino acids 290, 458 and 478, respectively. RT-PCR expression analysis indicated that CAPN7 mRNA was ubiquitously expressed in the 12 tissues examined, but the relative abundance was unevenly distributed in tissues. The CAPN7 mRNA levels in muscle of 6 and 9-month-old crossbred pigs were higher than those of Yorkshire pigs at the same ages. In addition, a missense mutation was identified by PCR-SSCP and its distribution in wild boar, Min pig and Duroc was significantly different. The results lay the foundation for further studying the function of CAPN7 gene.
