Genetic diversity in populations of Slovak Spotted cattle based on single nucleotide polymorphisms analyses
The aim of this study was to identify SNPs in leptin (LEP), leptin receptor (LEPR) and growth hormone (GH) genes in order to analyze genetic diversity of Slovak Spotted cattle. The total numbers of blood samples were taken from 353 Slovak Spotted cows originating from four farms. Genomic DNA was isolated by phenol-chloroform extraction method and analyzed by PCR-RFLP method. After digestion with restriction, enzymes were detected in whole population of cow's alleles with frequency: LEP/Sau3AI A 0.84 and B 0.16 (±0.0152); LEPR/BseGI C 0.95 and T 0.05 (±0.0089) and GH/AluI L 0.70 and V 0.30 (±0.0188). Based on the observed vs. expected genotypes frequencies populations across loci were in Hardy-Weinberg equilibrium (P\>0.05). Predominant for SNP LEP/Sau3AI was AA genotype (0.70), for SNP LEPR/T945M CC genotype (0.91), and LL genotype (0.48) was most frequent for SNP GH/AluI. The observed heterozygosity of SNPs across populations was also transferred to the low or median polymorphic information content 0.24 (He 0.28), 0.08 (He 0.09) and 0.33 (He 0.47) for LEP, LEPR and GH genes, respectively. Within genetic variability estimating negative values of fixation indexes FIS (-0.09-0.05) and FIT (-0.07-0.03) indicating heterozygote excess were observed. The value of FST indexes (0.018-0.023) shows very low levels of genetic differentiation in allele frequencies of loci among evaluated subpopulations. The low values of genetic distances (0.0018-0.0159) indicated high genetic relatedness among animals in subpopulations caused probably by common ancestry used in breeding program at farms.