VEGF-A locus plausibly associated with high altitude adaptation in yak is completely fixed in cattle population from high and low altitude environments
Pages : 16-20
Vascular endothelial growth factor-Alpha (VEGF-A) is essential for the growth of new blood vessels promoting angiogenesis and plays an important role in high altitude adaptation. In the present study, an effort was made to undertake comparative screening of SNPs at two specific positions in VEGF-A gene (g.8430T>C and g.14853G>A) in high altitude adapted Ladakhi cattle, cross bred maintained at high latitude, tropically adapted native cattle breeds and yak DNA samples . The PCR amplified product of corresponding region harbouring the two SNPs was investigated by PCR-RFLP approach to ascertain the allelic/genotypic distribution of VEGF-A variants in across Indian cattle and yak breeds. PCR- RFLP was performed in a total of 312 animals comprising 6 native cattle breeds, 1 cattle population from high altitude and 1 population of yak from north-eastern part of India. In addition, 60 samples of yak and native cattle were sequenced to detect any additional variation in the amplified region of VEGF gene. In yak, the genotyping at locus g.8430T>C reveals three genotypes viz. CC (245bp), CT (245+215bp) and TT (215bp). While at locus g.14853G>A, the genotypes identified in yak samples were; GG (241bp), GA (241+143bp+98 bp) and AA (143+98 bp). Interestingly, at both these positions, only single genotype was observed. At g.8430T>C, only C allele was present while at g.14853G>A, only G allele was present across all native cattle samples. The data showed complete fixation of C allele; CC genotype at locus g.8430T>C and G allele, GG genotype at locus g.14853G>A of VEGF-A gene in cattle breeds from both high and low altitude environments. Thus, the result of the present study indicated that both these loci of VEGF-A gene are not associated with high altitude adaptation trait of cattle population from Leh and Ladakh region of India.
Keywords: VEGF-A, PCR-RFLP, SNP, High altitude adaptation, Indian native cattle, Yak