Vol. 10, Special Issue 11 (2021)

Author(s):
Bhajantri Shankarappa, R Nagaraja, Yathish HM and SB Prasanna

Abstract:
The present study was carried out to explore the variants of CXCR1gene and their association with Somatic Cell Count (SCC) in Deoni and HF Crossbred cows. The CXCR1/BsaI analysis identified two genotypes AA and AG with respective frequencies of 0.17 and 0.83 in HF crossbred and 0.21 and 0.79 in Deoni cows. Allelic frequencies were 0.59 and 0.57 for a allele, and 0.41 and 0.43 for G allele in HF crossbred and Deoni cows, respectively. Sequence analysis confirmed the presence of 469bp nucleotides in CXCR1 gene fragment studied and revealed lack of variations in the restriction site of BsaI enzyme in ‘A’ allele of both HF Crossbred and Deoni cows. Multiple sequence comparison of ‘A’ allele of HF crossbred and Deoni cows using “ClustalW” method revealed two transitions viz. C>T at position 295 and A>G at position 299 in Deoni cows compared to HF crossbred cows. The chi-square analysis revealed significant difference between observed and expected genotypic frequencies in both HF crossbred (p<0.01) and Deoni (p<0.05) cows indicating deviation of both populations from Hardy–Weinberg equilibrium. Further, Chi-square analysis did not reveal any significant association between the genotypes and SCC in HF crossbred cows. However, a significant association (p<0.01) was observed between the CXCR1 genotypes and SCC in Deoni cows, where in majority of animals with AG genotype were mastitis free.