小尾寒羊微卫星与RAPD标记的研究

小尾寒羊是世界上具有非季节性发情和多胎特性的高繁殖率绵羊品种之一。选择4个位于绵羊6号染色体上且与FecB基因紧密连锁的微卫星标记，对小尾寒羊基因组进行PCR扩增后，采用最小二乘法估计各等位基因片段对产羔数的影响。分析结果表明，等位基因OarJIA-5、OarJIA-10、BM143-12和OarHH55-11可以作为小尾寒羊多胎位点的分子标记。从100条随机引物中筛选出18条引物，对小尾寒羊、大尾寒羊、洼地绵羊、滩羊等4个绵羊品种和鲁北山羊的基因组进行扩增，共扩增出146条带，其中94条表现出多态性，占64．60%，同时扩增出每个品种的特异性条带。采用Nei氏标准距离和NJ聚类分析对不同品种的遗传关系进行分析，结果表明，4个绵羊品种亲缘关系很近，提示它们可能起源于共同的原始祖先。

Studies on Microsatellite and RAPD Markers in Little-tailed Han Sheep

As a prolificacy sheep,Little tailed Han Sheep is characteristic of non seasonal estrus and high fecundity.Four microsatellite markers linked to FecB locus on 6 chromosome in ovine were analyzed for 108 animals by PCR and denaturing polyacrylamide gel electrophoresis.The results with least square analysis showed that alleles OarJ1A 5 (116 bp), OarJ1A 10 (126 bp), BM143 12 (116 bp), OarHH55 11 (141 bp) may produce significant effect( P <0 05) on litter size.The mean litter size of ewes carrying the above four alleles were 3 23,3 25,3 22 and 3 04 respectively.Eighteen high polymorphic RAPD primers selected from 100 random primers were used for analyzing genetic relationships among Little tailed Han Sheep,Wadi Sheep,Large tailed Han Sheep,Tan Sheep and Lubei Goat.The number of total amplified fragments was 146.Among all the alleles,96 showed polymorphisms.The NJ topology tree based on Nei' standard distance indicated that the genetic relationship was closer between Little tailed Han Sheep and Large tailed Han Sheep than that between the former and the other two sheep breeds.