Comparative analysis of A1 and A2 allele detection efficiency for bovine CSN2 gene by AS-PCR methods

Abstract

This study was aimed at conducting a comparative analysis of the efficiency in genotyping cattle by beta-casein locus using the allele-specific PCR methods. The results of the study have demonstrated the necessity to optimize the protocol for the use of AS-PCR to detect alleles A1 and A2. It was found that the use of non-optimized PCR protocols led to the genotyping errors, manifested regarding beta-casein locus (CSN2). The impossibility of using the touchdown PCR as an optimization instrument for AS-PCR was proven. The elaborated typing protocols were used to study the genetic structure of the cattle populations of different breeds, reared in Ukraine – Ukrainian Red-and-White dairy, Ukrainian Black-and-White dairy (two populations), and Charolais. It was found that locus CSN2 was polymorphic in all the cattle populations. The frequencies of allele A2 varied within 0.34–0.91 depending on the population of the animals, which may be conditioned by the specificities in the selection work. No deviation from the Hardy-Weinberg equilibrium was found in any investigated population of cattle.

Study of beta-casein gene polymorphism in dairy cattle populations of Ukraine

“…Thus, DNA monitoring of the ratio of beta-casein alleles in the genotype of stud bulls will enable to predict the possibility of creating dairy herds with the programmed milk quality, since an increase in beta-casein homozygosity of A2A2 in the next generation is possible, especially when using A2A2 homozygous stud bulls. This, in turn, will increase the competitiveness of local breeds, and accordingly give additional options for their preservation [10,12].…”