氡染毒小鼠外周血细胞差异表达基因的筛选与鉴定

目的 在建立氡染毒小鼠模型的基础上,筛选和鉴定氡染毒小鼠外周血细胞差异表达基因。方法 采用HD-3型多功能氡室对BALB/c小鼠动态吸入染毒,建立实验动物模型。按照小鼠吸入氡及其子体的累积剂量分为实验组(累积剂量105 WLM)和对照组(室内本底浓度,1 WLM)。采用RNA转录物5'末端启动机制技术(SMART)和抑制性消减杂交技术(SSH)构建正、反向消减cDNA文库,选取含有插入cDNA片段的克隆进行反向Northern杂交筛选上调或下调的阳性克隆。克隆的测序结果进行同源性检索和生物信息学分析。结果 在成功构建了消减cDNA文库基础上,挑取白斑390个,获得312个含有插入片段的单克隆,进行反向Northern杂交,分析基因的上调或下调水平。选取差异表达克隆41个进行测序及生物信息学分析,最终获得10条已知功能或有注释的差异基因片段和3条未知的表达序列标签(EST)。筛选出的差异表达基因涉及氧化损伤、细胞增殖和肿瘤发生等多方面的功能。结论 氡染毒可引起一系列基因表达的上调或下调,利用SSH技术可以筛选到氡染毒的差异表达基因,为探讨氡损伤机制提供参考。

Construction and identification of differential expression genes of peripheral blood cells in radon-exposed mice

Objective To screen and identify the differential expression genes on peripheral blood cells of mice based on the experimental animal model of radon exposure.Methods BALB/c mice were exposed in a type HD-3 multifunctional radon-room, with the accumulative doses of radon-exposure group at 105 WLM and control group at 1 WLM. Total RNA was extracted from peripheral blood cells and the methods of SMART for dscDNA synthesis and SSH for gene screening was applied. With the construction of the cDNA library enriched with differentially expressed genes,the pMD 18-T plasmid containing LacZ operator at the multiple cloning site was used to allow a blue_white screening. The TA clones were amplified by nested PCR and the reverse Northern blot was used to identify up and down regulation of the clones. The differently expressed cDNA was then sequenced and analyzed.Results The subtracted cDNA libraries were successfully constructed. A total of 390 recombinant white colonies were randomly selected. Among the 312 cDNA monoclones selected from both forward- and reverse-subtracted libraries,41 clones were chosen to sequence for their differential expressions based on reverse Northern blot. Among the 41 sequenced clones,10 clones with known function/annotation and 3 new ESTs with the GenBank accession numbers were obtained. Most of the known function/annotation genes were revealed to be related with cell proliferation,metabolism,cellular apoptosis and carcinogenesis.Conclusion The animal model of radon exposure was established and the cDNA library of peripheral blood cells was successfully constructed. Radon exposure could up- and down-regulate a series of genes. Differentially expressed genes could be identified by using SSH technique and the results may help exploring mechanisms of random exposure.