Study of SNP 775C>T polymorphism within the bovine ITGB2 gene in Polish Black-and-White cattle and in local breeds of cattle
The present study addresses the characteristics of the frequency and segregation of alleles determining the SNP 775C>T polymorphism within the bovine <i>ITGB2</i> gene in the Black-and-White cattle population as well as in two endemic breeds of Polish Red and Polish White-Back cattle population qualified to the international programme of genetic resource diversity preservation in farm animals. The SNP 775C>T polymorphism revealed three amplified restriction fragments of 31 bp, 77 bp and 108 bp, forming three genotypes <i>CC</i> (31 bp, 77 bp), <i>CT</i> (31 bp, 77 bp, 108 bp) and <i>TT</i> (108 bp). A group of randomly selected Black-and-White cows was characterized by a negligible percentage of homozygous genotypes <i>TT</i> (5.1%) and by a prevailing percentage of heterozygous <i>CT</i> (60.1%) and homozygous <i>CC</i> (34.8%). In contrast, the between breeds analysis revealed that cows involved in the programme of genetic diversity preservation had a high prevalence of homozygotes <i>CC</i> (Polish Red − 55.9%, Polish White-Back − 60.0%), and a low percentage of homozygotes <i>TT</i> (Polish Red − 8.8%, Polish White-Back − 5.7%) in comparison with the Black-and-White cattle population. The degree of homozygosity in groups of Polish White-Back cows (65.7%) and Polish Red cows (64.7%) was remarkably higher than that of the Black-and-White cows (39.9%).