SNPs analyses of the bovine LEP and PIT-1 genes by multiplex PCR-RFLP method and their effect on milk performance traits in Slovak Simmental cattle

Abstract

The aim of this study was detection of polymorphisms in leptin (LEP) and pituitary specific transcription factor (Pit-1) genes and their evaluation as a genetic markers affected milk performance traits in population of Slovak Simmental cows. The analyzed SNP of LEP gene is located in intron 2 on bovine chromosome 4 and SNP of Pit-1 gene in exon 6 on bovine chromosome 1. The total numbers of blood samples were taken from 288 samples of Slovak Simmental cows. Bovine genomic DNA was isolated by phenol-chloroform extraction method and used in order to estimate LEP/Sau3AI and Pit-1/HinfI genotypes by means of MULTIPLEX PCR-RFLP method with using Sau3AI restriction enzyme for LEP and HinfI restriction enzyme for Pit-1. In the population of Slovak Simmental cattle were detected genotype AA (390 and 32 bp), genotype AB (390, 303, 88 and 32 bp), genotype BB (303, 88 and 32 bp) for LEP gene and genotype AA (260 bp), genotype AB (260, 190 and 70 bp), genotype BB (190 and 70 bp) for Pit-1 gene. The predominant alleles were A with observed frequency 0.8385 and B with 0.7743 for LEP and Pit-1, respectively. In both analyzed polymorphisms were frequent animals with dominant homozygous genotype. Frequency of SNP LEP/Sau3AI AA genotype was 0.7014 and SNP Pit-1/HinfI BB genotype was 0.6007. The statistical analysis show significant effect only between LEP/Sau3AI genotype and milk yield in standard length of lactation (P≤0.05), with A as a desirable allele. In genotype comparison produced AA genotype cows significantly more milk, with difference amounting 457.9 and 293.9 kg and therefore this animals might have potentially positive effect on milk yield. The other results from the statistical association analysis between LEP/Sau3AIand Pit-1/HinfI genotypes and milk production parameters – milk, protein and fat yield (kg) in standard length of lactation were not significant.