Polymorphism of LEP and TNF-α Genes in the Dairy Cattle Populations of Ukrainian Selection

Abstract

Study was conducted by investigating the genetic structure of cattle populations of Ukrainian Black-and-White and Ukrainian Red-and-White dairy breeds by polymorphism of leptin gene (LEP) and tumor necrosis factor-alpha gene (TNF-α). The studies were carried out using the method of polymerase chain reaction (PCR) and restriction analysis for LEP and using classic PCR with subsequent SSCP analysis in case of TNF-α. According to the results of the study, it was shown that the LEP gene was polymorphic in both experimental populations by HphI-polymorphism in the third exon of the gene (A59V mutation). In the population of the Ukrainian Black-and-White dairy cattle breed, the frequency of allele C (HphI-) was 0.77; allele T (HphI+) – 0.23. Wright's fixation index was 0.23; which indicates a significant excess in the number of homozygous individuals. This population had a deviation from the Hardy-Weinberg equilibrium state. In the population of the Ukrainian Red-and-White dairy breed, the frequency of allele C was 0.72; allele T – 0.28; Wright's fixation index was -0.18. According to the SSCP-polymorphism of the TNF-α gene, 6 alleles with a size of 450-1200 bp were detected (alleles A, B, and F for Ukrainian Black-and-White dairy breed; A, B, C, D, Е, F – for Ukrainian Red-and-White dairy breed). The frequency of allele A prevailed in the populations of both breeds (0.58 and 0.54, respectively). Alleles C, D, and E had a low frequency of occurrence (0.04-0.16) and they were found only in the population of Red-and-White dairy breed.