绵羊心脏脂肪酸结合蛋白基因单核苷酸多态性分析

试验旨在探讨心脏脂肪酸结合蛋白（heart fatty acid-binding protein，H-FABP）基因在绵羊中的遗传多态性，并寻找可用于辅助选择的分子标记。本研究以滩羊（250只）及滩羊×湖羊杂交F1代（174只）为试验动物，利用SNaPshot分型技术对H-FABP基因（GenBank登录号：AY157617）的多态位点进行单核苷酸多态性（SNP）分析，统计基因频率和基因型频率，进行Hardy-Weinberg平衡性检测，计算期望杂合度（He）、多态信息含量（PIC）和有效等位基因数（Ne）等遗传多态指标，分析候选基因不同基因型与体重、体长、体高、胸围、胸深、胸宽和管围等生长性状的关联性。结果显示：①检测到9个多态位点：939A/G]、980G/A]、1018T/C]、2878C/T]、2956C/T]、3017G/A]、3341G/C]、3394T/A]、1056-/G]，其中有6处转换、2处颠换、1处单碱基插入。②939A/G]、980G/A]、2956C/T]、3341G/C]、3394T/A]和1018T/C]的He为0.3200~0.4666，PIC为0.2688~0.3577；2878C/T]、3017G/A]位点的He为0.0283~0.1272，PIC为0.0279~0.1191，为低度多态；1056-/G]位点的He在滩羊、滩羊×湖羊杂交F1代群体中分别为0.0120和0，PIC在滩羊、滩羊×湖羊杂交F1代群体中分别为0.0119和0；9个多态位点在滩羊、滩羊×湖羊杂交F1代群体中均符合Hardy-Weinberg平衡定律。③5个多态位点：939A/G]、980G/A]、2956C/T]、3341G/C]、3394T/A]处于紧密连锁（D'>0.99），将H-FABP基因分为3个单倍型：AA、AB和BB。④在41只滩羊×湖羊杂交F1代羊中，BB单倍型在各生产性状上具有最大值，但各单倍型间差异不显著（P>0.05）。结果表明，绵羊H-FABP基因具有丰富的遗传多态性，939A/G]、980G/A]、2956C/T]、3341G/C]、3394T/A]5个位点紧密连锁，BB单倍型可能是与绵羊生产性状相关的优势单倍型。

Analysis of Single Nucleotide Polymorphism of Sheep H-FABP Gene

This experiment was aimed to study the genetic polymorphism of heart fatty acid binding protein (H-FABP) gene in sheep, and find the molecular marker-assisted selection. Tan sheep (250) and Tan×Hu hybrid F1 generation (174) were used as the experimental animals to detect single nucleotide polymorphism (SNP) of H-FABP gene (GenBank accession No.:AY157617) using SNaPshot technology. Gene frequency and genotype frequency statistics, Hardy-Weinberg equilibrium (HWE), expected heterozygosity (He), polymorphism information content (PIC) and effective number of alleles (Ne) were calculated. The correlation among the gene in different genotypes and body weight, body length, body height, chest circumference, chest depth, chest width and cannon circumference traits was analyzed. The results showed that 9 polymorphic loci were detected:939A/G], 980G/A], 1018T/C], 2878C/T], 2956C/T], 3017G/A], 3341G/C], 3394T/A] and 1056-/G], including 6 transitions, 2 transversions and 1 single-base insertion. The He at 939A/G], 980G/A], 2956C/T], 3341G/C], 3394T/A] and 1018T/C] was 0.3200 to 0.4666, PIC ranged from 0.2688 to 0.3577; The He at 2878C/T] and 3017G/A] was 0.0283 to 0.1272, PIC ranged from 0.0279 to 0.1191 for low polymorphism; The He at 1056-/G] in Tan sheep was 0.0120,whereas that of Tan×Hu hybrid F1 generation was 0, PIC in Tan sheep was 0.0119, whereas that of Tan×Hu hybrid F1 generation was 0.9 polymorphic loci in Tan sheep and Tan×Hu hybrid F1 generation followed Hardy-Weinberg equilibrium. 5 polymorphic loci of 939A/G], 980G/A], 2956C/T], 3341G/C] and 3394T/A] were tightly linked (D'>0.99), and H-FABP gene was divided into 3 haplotypes:AA,AB and BB. BB haplotype had the maximum value in each production traits in 41 Tan×Hu hybrid F1 generation, but the difference was not significant (P>0.05). H-FABP gene in sheep had abundant genetic polymorphism,5 polymorphic loci of 939A/G], 980G/A], 2956C/T], 3341G/C] and 3394T/A] tightly linked,BB haplotype might be the dominant haplotype associated with production traits in sheep.