[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 x SH F1 (23), Poll Dorset (48) and Suffolk (24) sheep were screened in this study. 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 x SH F1 populations (PIC amp; 0.25) but an intermediate PIC in the remaining three populations (0.25 amp; PIC amp;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 amp; 0.25). However, there was no polymorphisms in SH, Tan x SH F1 and Suffolk populations.

[Variation of MSTN gene UTR in eleven sheep breeds].

PCR-RFLP was applied to analyze the polymorphism of MSTN gene UTR in 345 sheep that comprised of eleven sheep breeds, namely Texel sheep, Charolais sheep, Small-tailed Han sheep, Monggolian sheep, Ujumqin sheep, Altay Fat-rumped sheep, Hulunbeir sheep, Tashikurgan sheep, Duolang sheep, Hu sheep, and Gangba sheep. A 271 bp and a 1 003 bp long PCR products were digested with Mboand Bsato demonstrate polymorphism in the eleven sheep breeds, which were all at Hardy-Weinberg equilibrium (P>0.05). The distribution of 3 genotypes in 11 sheep breeds was significantly different (P<0.01). Digestion of the PCR products with HpyCH4 proved that 9 domestic local sheep breeds were different from Texel sheep in the SNP site that was associated with muscularity. The individual mutation base could generate the motifs for miRNA in the 3'UTR, and sequencing analysis demonstrated high frequency of mutation in the 3'UTR region.