Analysis of CSN2 variants in Friesian Holstein cows and their association with milk protein allergy and production traits

Abstract

<p><strong>Objective: </strong>The objective of this study was to analyze <em>CSN2</em> variants in Indonesian Friesian Holstein (FH) cow and their association with milk protein allergy and production traits.</p><p><strong>Methods: </strong>Genomic DNA was extracted from bloods of twelve Indonesian FH cow. Exon 7 of the <em>CSN2</em> was amplified using novel primer pair to produce 683 bp amplicon. The primers were 5’-ACCCCAATTTCTTAACCAAACCA-3’ as a forward primer and 5’-CATCAGAAGTTAAACAGCACAGT-3’ as a reverse primer. The PCR products were analyzed to determine the nucleotide sequence of <em>CSN2</em> using Bioedit version 7.2.5. Moreover, Hardy-Weinberg equilibrium (HWE) was calculated and one-way analysis of variance (ANOVA) was conducted to associate between <em>CSN2</em> variants and milk production traits.</p><p><strong>Results: </strong>Two polymorphisms, c.350A>C and c.516G>C, were identified in the <em>CSN2 </em>exon 7. Base substitution from adenine (A) to cytosine (C) of c.350A>C changed amino acid codon from histidine (CAU) to proline (CCU), and base substitution guanine (G) to cytosine (C) of c.516G>C changed amino acid codon from arginine (AGG) to serine (AGC). The CC genotype frequency for c.350A>C SNP was 33% and they were able to produce A2 <em>CSN2</em> variant which is favorable for preventing lactose intolerance. In addition, there were no association between c.350 A>C and c.516 G>C SNP of the <em>CSN2</em> with milk production traits.</p><p><strong>Conclusions: </strong>In conclusion, A1 and A2 variants of <em>CSN2</em> were identified in Indonesian FH population and they did not associate with milk production in Indonesian FH.</p><p> </p>