中文摘要：

[目的]构建以缺失不同功能区的猪内源性反转录病毒（PERV）5＇＇非编码区（5＇＇UTR）为启动子的萤光素酶表达载体,分析5＇＇UTR的转录调控规律.[方法]将含有不同功能域的PERV的UTR克隆至萤光素酶表达载体上,转染瞬时表达细胞Cos-7,检测萤光素酶的表达.[结果]缺失R区的5＇＇UTR显示出很强的启动子活性,U3重复区序列缺失的5＇＇UTR启动子活性显著下降.UTR显示出较之LTR强的启动子活性.缺失整个U3区的UTR比仅缺失U3重复区的UTR启动子活性强.[结论]在R区有转录因子的结合位点可引起转录活性下降;U3重复区序列表现出增强子的活性.在5＇＇UTR的下游序列中,包括引物结合区（PBS）和前导序列（Leader）可能有某些转录因子的结合位点引起转录增强,同时在U3重复区的上游和下游序列可能存在某些转录因子的结合位点可减少5＇＇UTR的转录活性.

英文摘要：

[Objective] The study analyzed the transcriptional regulation of porcine endogenous retrovirus （PERV） 5＇ untranslated region （5＇UTR）. [ Method ] A series of functional region deletion of PERV 5＇UTR were cloned, including completed 5＇UTR, 5＇UTR lacking of PBS and Leader（5＇LTR）, 5＇UTR lacking of U3 region, 5＇UTR lacking of R region, 5＇UTR devoid of the U3 repeat box. Scientists then studied the activity of UTRs from replication-competent molecular clones by performing luciferase reporter assays. [Result] The UTR has higher promoter activity than that of LTR. 5＇UTR lacking the R region showed strong promoter activity, whereas for 5＇UTR devoid of the U3 repeat box, the promoter activity was significantly decreased. 5＇UTR lacking the entire U3 displayed higher promoter activity than that of 5＇UTR only lacking the U3 repeat box. [ Conclusion ] There may have been an interaction of some factors with the R region causing suppressed activity. The U3 repeat box acted as an enhancer; where the downstream sequence of 5＇UTR （PBS and Leader） may have had transcription factors＇ binding sites regulating this positive effect. The upstream sequences of U3 may have cis-elements that reduce the transcriptional activation of 5＇UTR.