Polymorphism of the retinol-binding protein 4 gene (RBP4) and its association with carcass and meat quality traits in swine

To investigate the influence of the retinol-binding protein 4 gene (RBP4) on the carcass and meat quality traits of swine, polymorphism was observed by PCR-SSCP in four Chinese native pig breeds (Huoshouhei, Anqingliubai, Wannanhei, and Wei), that were carefully selected for economic traits. The results revealed one SNP (A>G) of the RBP4 gene in these breeds, excluding Huoshouhei. The AA genotype was the predominant genotype and allele A was the predominant allele with higher frequencies. A further analysis of SNP genotypes associated with carcass and meat quality traits including slaughter rate, average back-fat thickness, eye muscle area, lean percentage, meat color, L* value, a* value, b* value, pH 1, pH 24, drip weight loss, intramuscular fat (IMF) content, and shear force was carried out in three pig breeds including Anqingliubai, Wannanhei, and Wei. The results showed that individuals with AA had a higher back-fat thickness and a lower eye muscle area than those with AG and GG. Meanwhile, individuals with AA had a higher a* value than those with AG and GG. However, differences of other traits such as lean percentage, pH, drip weight loss, IMF content, and shear force among different genotypes were irregular. In conclusion, the SNP (A>G) in the porcine RBP4 gene may be a potential genetic marker for back-fat thickness, eye muscle area, and meat color a* value selection in pigs.