POLYMORPHISM OF MELANOCORTIN RECEPTOR GENE MC4R AND THEIT EFFECT ON THE GROWTH AND MEAT PRODUCTIVE TRAITS OF PIGS
The study of G^A polymorphism in position 1426 of melanocortin receptor gene MC4R leading to the amino acid substitution Asp298Asn was carried out. The analysis was performed on 33 pig populations of different breed and origin (n=2072): Large White (9 populations), Landrace (8 populations), Duroc (4 populations), Yorkshire, Pietreain, Edelschwein, Livenskaja, Body, six different types of crosses and wild pig. The polymorphism of MC4R was detected using PCR RFLP analysis. The breed specific character of allele frequencies of MC4R gene was observed. The allele A frequency is varied of 6.7 per cent in Pietrain to 93.3 per cent in French Large White pigs. The higher frequency of allele A in Large White pigs (75.8±6.5 per cent) comparing to Landrace (34.4±5.7%, p<0.001) and Duroc (59.7±11.1 per cent) was observed. The breed aspect of MC4R allele frequency pattern was confirmed by analysis of variance: intra population variability of MC4R caused by breed effect was significantly higher comparing to within population variability. The breed factor effect was 18.4 per cent (p<0,001). MC4R genotype frequencies were in Hardy-Weinberg equilibrium in all pig populations analyzed. Analysis of growth and meat productive traits in dependence of MC4R genotype performed on nine groups of pure breed pigs and crosses of different origin showed the tendency of larger back fat and higher carcass length in pigs with AA genotype comparing to GG genotype.