Effects of calpastain (CAST) polymorphisms on carcass and meat quality traits in Mongcai pigs

Calpastain (CAST) activity plays a major role in muscle growth and proteolytic changes post-mortem and the CAST gene has been considered as a candidate gene for carcass and pork quality characteristics. The aim of this study was to analyze the association of two polymorphisms namely CAST_Hinfl (allele A and B) and CAST_Mspl (allele C and D) with carcass and meat quality traits in Mongcai, a Vietnamese indigenous pig breed. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype the animals at these loci. Results indicate that the CAST_Hinfl single nucleotide polymorphism (SNP) had a low frequency of allele A as compared to allele B, while the C and D allele distribution was almost the same for the CAST_Mspl SNP. In the association analysis, significant effects on dressing percentage of carcass were detected. The CAST_Hinfl locus was associated with the pH sub(24), while the CAST_Mspl position was in association with pH sub(45min), drip loss sub(48) and redness color. Additional analysis showed a variation in muscle fiber type composition with higher proportion of Ilx fiber in pigs with AB genotype (P < 0.05). Three constructed haplotypes namely AB/CD, AB/DD and BB/CC also had significant effects on carcass, type Ila and Ilb fiber percentages.