Study of polymorphism in the bovine HSP70 gene promote and its association with conception rate in Holstein and Sarabi breeds

The objective of the present study was to determine single nucleotide polymorphisms (SNP) located in the promoter region of the bovine heat shock protein 70 (Hsp70) gene. And evaluate associations between Hsp70 SNP with conception rates in Holstein and Sarabi cows. Blood samples were collected from 124 cows. The Cows were Holstein (n=72) and Sarabi (n=52). Genomic DNA was extracted using modified salting-out method. The quantity and quality of extracted DNA were examined with spectrophotometery and gel electrophoresis. Specific primers were designed for PCR amplification of a 539 base segment of the bovine Hsp70 promoter. The polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method was used to scan for mutations within the amplified regions. The polymorphisms were confirmed by direct sequencing. Seven single nucleotide polymorphisms were detected; one deletion at base position 895 four transitions (G1045A, G1117A, 1134C and T1204C), and two transversions (A1125C, G1128T). And also four haplotypes were detected (CAAAGCC, DGGCTTC, CDGGCTTT, CGGAGTT). Statistical analysis showed polymorphism in the promoter region of the bovine heat shock protein 70 region significantly correlated with conception rate (P <0.0001). Interestingly in Holstein breed the haplotype (CGGAGTT) of the significant mean conception rate heavier than had haplotypes (DGGCTTC, CDGGCTTT) and in Sarabi breed the haplotypes (CGGAGTT,CAAAGCC) of the significant mean conception rate heavier than had haplotype (DGGCTTC) (P< 0.01). The result of present study verified candidate SNPs within the promoter region of the bovine Hsp70 gene may be useful in selecting cows with a greater fertility.