Frequency distribution of polymorphic variants of the beta-casein locus in Russian various breed cattle subpopulations

Natalia Kovalyuk,Zaurbek Aisanov,Lyudmila Yakusheva,Elena Shiryaeva,Vladimir Kaishev,R.Z Abdulkhalikov

doi:10.1051/e3sconf/202126202020

Natalia Kovalyuk, Zaurbek Aisanov + Show 4 more

Open Access

https://doi.org/10.1051/e3sconf/202126202020

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Abstract

Using the author’s test system, 2607 Holstein, Ayrshire and Jersey breeds were genotyped at CSN2 locus. It was determined that the frequency of preferred genotype A2A2 is in Holstein, Ayrshire and Jersey groups of animals - 0.21; 0.25 and 0.60 respectively. The frequency of A2 allele in Holstein breed is 0.48; in Ayrshire - 0.51; in Jersey - 0.78. Thus, the Russian subpopulations of Ayrshire, Jersey, and Holstein cattle subpopulations according to frequencies of A2A2 genotypes (CSN2 locus), the Jersey breed has the best indicators (0.60). Russian breeding enterprises selling semen production of Ayrshire and Holstein bulls should increase the share of breeders with CSN2 genotypes A2A2.

Highlights

For β-casein gene (CSN2), 12 polymorphic variants were described
Using the author's test system, 2607 Holstein, Ayrshire and Jersey breeds were genotyped at CSN2 locus
It was determined that the frequency of preferred genotype A2A2 is in Holstein, Ayrshire and Jersey groups of animals - 0.21; 0.25 and 0.60 respectively

Summary

Introduction

For β-casein gene (CSN2), 12 polymorphic variants were described. It was concluded that the mutation causing differences in the casein protein is considered the result of a single nucleotide polymorphism (C/A) in codon 67 in exon 7 of the beta-casein gene, that is the CCT codon (A2, proline) is changed to CAT (A1, histidine)). It is believed that this mutation arose about 5000 years ago and spread widely in various cattle breeds. It was detected [4] that in such dairy cattle breeds as Guernsey, Schwyz, Jersey, Holstein, Ayrshire and Red Danish the frequency of the A1 allele ranges within 42%, 34-30%, 50-37%, 56-47%, 60-51% and 77%, respectively. In light of the ever-increasing requirements for dairy products quality, it is important to determine the potential of Russian subpopulations of Holstein, Ayrshire and Jersey breeds in terms of beta-casein locus selection

Materials and Methods

Results and Discussion

Conclusions