Associations between promoter polymorphisms in key genes of lipid metabolism and miogenesis and economically valuable traits in pigs

Motivation and Aim: Huge sets of gene expression pro fi les (GEP) data, in particular for farm animals, collected over the last two decades. The main aim of such data-sets is to search for gene expression differences associated with economically valuable traits. In an earlier article we showed subdivision of GEP into constitutive and variable part according to the individual changes in gene expression. Interesting, that difference in expression of genes from the second group can be possibly explained by effect of paratypic component [1]. In a present research we checked a possible in fl uence of genetic component on association between regulation of gene expression and development of economically valuable traits. It was done by association analysis of mononuclear promoter polymorphisms in key genes of lipid metabolism, control of myogenesis and meat and fat characteristics of two different industrial pig crosses. Methods and Algorithms: Polymorphic promoter regions of Acyl-CoA desaturase (SCD) [-233 T/C], Leptin (LEP) [-11606 C/T; -12109 T/A], Myoblast determination protein 1 (MYOD) [-38 G/A], Myogenic factor 6 (MYF6) [-375 T/C], Osteopontin (OPN) [-24 G/A] were genotyped with KASPar system directly from genomic DNA of two- and three-breed pig crosses of Italian selection. Phenol – chloroform extraction was used to isolate DNA from muscle tissue. Statistical analysis was carried out using the SPSS 17.0 software (SPSS statistics; 2008) Statistica 7.0 (StatSoft Inc, 2004), MedCalc Software 12.0.3, Microsoft Excel. Results: The frequencies of alleles and genotypes showed noticeable differences for all studied SNPs. Among all genes except Lep two-breed cross differ from three- breed cross with higher level of heterozygosity. Most of associations (P<0,05) were observed for promoter SNP of Opn gene and back fat, characteristics of meat production of two-breed cross. Interesting, that revealed associations of production traits and SNP genotypes in promoter region are breed and sex-dependent. Associations between all SNP genotypes and average daily gain in different periods of ontogenesis were observed only for three-breed cross pigs (P < 0,05,P < 0,01,P < 0,001). Conclusion: Received data demonstrates that associations between genotypes in promoter region of key genes of lipid metabolism, genes controlling myogenesis and production traits among analyzed groups of pigs depend on sex, genetic background (two- and three-breed crosses) and stages of development. Obviously complicated character of genetic component in fl uencing regulation of the key genes of economically valuable production traits can endow to variable part of GEP