微卫星技术在绵羊品种级进杂交育种中的应用

分析了10个微卫星基因座10个微卫星标记在7个绵羊群体（德美♂×当地羊♀级进杂交一代、级进杂交二代、级进杂交三代、德克赛尔、道赛特羊、德国美利奴羊、当地羊）205只绵羊中的遗传多态性。结果表明，这10个微卫星标记在7个绵羊群体中的等位基因数分别为12、22、26、23、14、21、29、17、24和14，由多态信息含量／有效等位基因数／杂合度可知其中AGLA269的遗传变异最大，BMS1714最小。基于Nei氏距离和共祖遗传距离，采用UPGMA方法构建了系统发生树。该发生树将德美×当地羊级进杂交一代、二代、三代和德国美利奴羊归为一类后又与当地羊聚为一大类，将德克赛尔、道赛特羊归为另一类。绵羊微卫星基因分型技术为检查品种（群体）之间的遗传关系提供了一个有用的工具。

Genetic Structure of Grading Breeding in Sheep by Microsatellite Marker Technology

The genetic polymorphisms of ten microsatellite loci and ten microsatellite markers were analyzed in 205 sheep of seven sheep populations （grading crossing F1 of Germany Merino ♂× local sheep♀ ,grading crossing Fz of Germany Merino♂× local sheep~ ,grading crossing Fs of Germany Merino ♂× local sheep ♀, Texel sheep, Dorset sheep, Germany Merino, local sheep）. The numbers of alleles for BMS574, BMS1678, BMS1248, BM304, BMS695,BMS710,BM3501,MB009,AGLA269 and BMS1714 were 12,22,26,23,14,21,29,17,24 and 14 in seven sheep populations,respectively. The results indicated the greatest genetic variation at AGLA269 locus and the lowest at BMS1714. The dendrograms was created by the method of unweighted pair group method with arithmetic mean （UPGMA） dendrograms based on Nei＇s DA distance and Nei＇s DS standard genetic distance. The grading crossing F1 of Germany Merino ♂× local sheep ♀, grading crossing F2 of Germany Merino ♂× local sheep ♀, grading crossing Fs of Germany Merino ♂× local sheep ♀ ,and Germany Merino were grouped together,then with local sheep. The Texel sheep and Dorset sheep also clustered together. Microsatellite genotyping in sheep provided a useful tool for examining the genetic relationships among varieties（populations）.