Genetic variability of alpha-casein, beta-casein, and kappa-casein genes in Holstein-Friesian, Simmental and Brown Swiss cattle

This study aims to determine the genotypes and allele frequencies of polymorphisms of bovine αS1-casein (CSN1S1), αS2-casein (CSN1S2), β-casein (CSN2) and κ-casein (CSN3) genes in Holstein-Friesian, Simmental, and Brown Swiss breeds. DNA was isolated from milk samples. It was performed for amplification of gene regions according to multiple PCR protocols determined by optimization. Sanger sequencing was performed to genotyping PCR products. CSN1S1 gene and CSN1S2 gene in three cattle breeds were observed to be monomorphic. The CSN2 gene was observed three different genotypes in Holstein-Friesian, two different genotypes in Brown Swiss. But Simmental breed was observed monomorphic. For the CSN3 gene was observed three different genotypes in Holstein-Friesian and Brown Swiss, two different genotypes in Simmental. Also, the sequence region in the bovine CSN2 gene exon 7 in this study was performed alignment (BLAST) in NCBI, Ensemble and DDBJ.  The C→G transition in consequence of alignment (BLAST) reported in this study was encountered in no previous study.  Therefore, this SNP is thought to be detected for the first time. However, it was concluded that it would be appropriate to carry out more studies on this new SNP point.