Study on single nucleotide polymorphisms of H-FABP gene in sheep.

PCR-SSCP and DNA sequencing approaches were applied to assess the single nucleotide polymorphisms(SNPs) and analyze the genetic polymorphisms at partial exon 2 and intron 2 of H-FABP(Heart fatty acid-binding protein)gene,and five sheep populations that comprised of Small-Tailed Han sheep(SH,48),Ningxia Tan sheep(Tan,121),Tan × SH F1(23),Poll Dorset(48) and Suffolk(24) sheep were screened in this stuty.The result showed:(1)four SNPs at 981(G/A),1014(A/C) 1019(T/C) and 1058(-/G) and nine genotypes(AA,BB,CC,AB,AC,BC,AD,CD and BD) were detected using primer 2,the AA was the predominant genotype.A chi-square analysis suggested that the allele frequencies and genotype frequencies of H-FABP were in Hardy-Weinberg equilibrium except the Tan and Suffolk populations.Statistical analysis revealed a low polymorphism information content(PIC) in the Suffolk and Tan × SH F1 populations(PIC 0.25) but an intermediate PIC in the remaining three populations(0.25 PIC 0.50).It meant that the fragment of H-FABP had polymorphisms,which could be used as a candidate gene associated gene with phenotypic traits like intramuscular fat content in different sheep populations.(2)Three genotypes(HH,Hh and hh) determined by a SNP at 2407(T-C) were detected using primer 4.The genotype frequencies were in the order of HHHhhh.A chi-square analysis suggested that the allele frequencies and genotype frequencies of H-FABP were in Hardy-Weinberg equilibrium in the Tan and Poll Dorset populations,and the PIC values were low(PIC 0.25).However,there was no polymorphisms in SH,Tan × SH F1 and Suffolk populations.