三疣梭子蟹微卫星标记的筛选及特征分析

微卫星序列包含有多种重复单元，在其两碱基重复的类型当中，CT／GA重复类型在功能基因组中比例较高。三疣梭子蟹是重要的养殖品种，对遗传种质的分析需要开发大量的分子标记，本文利用5’锚定引物PCT筛选三疣梭子蟹的CT／AG微卫星分子标记，测序的41个克隆子中，35条序列含有微卫星DNA序列，阳性克隆比率达到85．4％，共检测到55个微卫星位点，分布于20条序列中，其中19条序列检测到2个或2个以上微卫星位点。对所有筛选到的微卫星位点进行分类统计后表明，核心序列为（CT／AG）的有27个（50％1，27个位点为其他类型的重复。结果表明三疣梭子蟹CT／AG微卫星标记在三疣梭子蟹基因组中含量较丰富，5’锚定引物法在筛选特定标记的同时，还筛选了其他类型的微卫星标记，具有较强的筛选效率。

Isolation and Characterization Microsatellite Markers in Portunus trituberculatus

In this study, CT/AG microsatellite markers were separated using 5＇anchored primer PCT in swimming crab genomic DNA. Among the 41 sequenced colons, 35 （85.4%） sequences have microsatellites. A- part from some replications, 55 microsatellites were searched in 20 sequences. And 19 sequences have more than one microsatellite. The classifying for the repeat types of these microsatellites performed that among the 55 microsatellites, 27 microsatellites （50%） were CT/AG type and 27 were other types. The results showed that CT/AG microsatellite was abundant in P. trituberculatus; Additionally some other type microsatellites were isolated at the same time using 5＇ anchored primer. The selection efficiency was raised significantly.