The association between polymorphisms of three cathepsins and economically important traits in pigs raised in Poland

The cathepsins belong to the enzymes of cathepsins family, which collect lysosomal proteinases. They have a wide spectrum of function in a lot of tissues and cell types. In pigs, they are extensively tested in relation to muscle transformation during dry-cured ham processing. Porcine CTSZ gene was mapped on SSC17 in the region which is suggestive of QTLs for meat quality. The CTSF and CTSD genes were localized on SSC2, at a distance of 13 cM. In the CTSZ and CTSF genes missense mutations g.37A > G and g.22G > C were identified. While in CTSD gene, SNP in 3'UTR was discovered (A70G). We investigated the associations between these three SNPs and economically important traits in Polish pigs. The significant effect of A70G CTSD polymorphism was detected for two growth traits. Animals carrying A/G genotype had lower daily gain and higher number days in test than both homozygotes (AG-853 g/day and 180 days; P < 0.01). The pigs with AA genotype of CTSD had higher level of meat traits and lower backfat thickness than GG pigs. Investigation of impact of mutation in CTSF on pig traits did not revealed obvious results. Analysis of mutation in CTSZ gene delivered two significant differences between GG and AG pigs, which were 75 g/day for TDG and 10 days NDT. To summarize, research on CTSD and CTSZ genes should be continued in order to find an additional QTL on SSC2 and SSC17 associated with economically important traits. (C) 2012 Elsevier B.V. All rights reserved.