Polymorphism scanning of HSP90AB1 gene in local Friesian Holstein as molecular marker for heat stress resistance

Abstract

Heat stress poses major problem in dairy cattle in term of reproduction and milk yield, especially in humid tropical climates. The HSP90AB1 is a gene that plays important role in heat stress response. Scanning its allele and genotype variation could be beneficial for the selection of dairy cattle which able to cope with heat stress effect. This study aimed to identify HSP90AB1 gene polymorphism (SNP g.4338T>C) in Indonesian local Friesian Holstein dairy cattle population. In total 20 cattle were sampled randomly. In this study, AS-PCR was employed to amplify 561 bp of gene fragment, using pair of primer namely CF primer 5-CTGGAGTCACACTGAGGAAC-3, TF primer 5-CTGGAGTCACA CTGAGGAAT-3, F primer 5-CTGGAGTCACACTGAG-3, and R primer 5-TGTTGGAGATCGTCACCTG-3. As the results, allele T and C were observed, and respective frequencies are 0.35 and 0.65. Three genotypes of HSP90AB1 gene were found namely CC, CT, and TT. The respective genotype frequency is 0.1, 0.5, and 0.4. According to Hardy-Weinberg analysis, the population is in equilibrium (P>0.05). It is concluded that CT genotype and T allele are the highest frequency in the sampled population. Further study needs to be performed to associate the genotype and allele variation to productivity trait of local dairy cattle.