The effect of cystatin B gene (CSTB) on productive traits in pigs.

Cystatin B gene is a candidate gene for carcass and meat quality traits of pigs and belongs to the family 1 of cysteine proteinase inhibitors. The enzyme is a cathepsin inhibitor and the proteolytic cystatin/cathepsin system plays an important role in the growth and development of muscles. Investigations presented here covered 707 pigs from different genetic groups reared in Poland. The aim of this study was to characterise the polymorphism of the CSTB gene identified with restriction endonuclease: TaqI and PvuII, and to analyse the relation between the CSTB genotypes and carcass traits. All tested animals proved to be monomorphic at the CSTB/TaqI locus. All three possible genotypes were observed with regard to the second CSTB/PvuII locus. In Polish Large White and Polish Landrace pigs the highest frequency was reported for BB homozygotes. The association between CSTB and carcass traits was found only in Polish Landrace pigs for the meat content of carcass, meat content of valuable cuts and weight of the loin.