Objective To isolate microsatellite markers in tree shrews ( Tupaia belangeri chinensis) , and to fill the gap of lack of specific genetic markers of tree shrews. Methods A partial genomic library was constructed in tree shrews. Thirty-six positive clones were isolated from screening about 1500 clones of the genomic library with ( CA) 15 probe labelled at the 5' end with digoxin. Sequences of these clones and 15 microsatellites were isolated which included one repeated clones and one short flank sequence. Results The other 13 primers were designed based on unique sequences flanking each motif with the software Primer3. PCR assays were performed with these primers, and all gave expected bands. Annealing temperature of these primers was between 44℃ and 52℃. So the positive cloning efficiency was 2. 4% , and the microsatellite cloning efficiency was 1%. Conclusions The microsatellite cloning efficiency of isolating microsatellite markers in tree shrews with probe labelled by digoxin is almost the same as that of probe labelled by radioisotope, yet avoided the radioactive contamination. The new polymorphic microsatellite markers we have identified and characterized will contribute to the tree shrew genetic linkage mapping, molecular evolution and marker-assisted selection.%目的 筛选中缅树鼩微卫星分子标记,逐步填补中缅树鼩特异性遗传标记的空白.方法 建立中缅树鼩基因小片段插入文库,利用5’端地高辛标记的(CA)15探针从约1500个菌落中选出36个阳性克隆.对这些克隆进行测序,发现其中15个含有重复序列,其中1个为重复克隆,1个因两端序列太短而不能设计引物.结果 用Primer3软件设计13对引物.PCR结果,13对均有条带.退火温度分布在44～52℃之间.阳性克隆率为2.4％,微卫星克隆率为1％.结论 利用地高辛标记探针筛选树鼩微卫星分子标记所得的微卫星克隆率,可达到传统放射性核素标记探针同等的效果,并可避免放射性危害.树鼩微卫星分子标记的筛选将为下一步进行基因组结构的分析、树鼩遗传连锁图谱的构建、分子进化和标记辅助选择等提供大量的微卫星标记.
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