遗传 ›› 2016, Vol. 38 ›› Issue (8): 724-735.doi: 10.16288/j.yczz.16-082

• 研究报告 • 上一篇    下一篇

鸡miR-17-92基因簇上游调控区功能分析

程敏1, 2, 3, 张文建1, 2, 3, 邢天宇1, 2, 3, 闫晓红1, 2, 3, 李玉茂1, 2, 3, 李辉1, 2, 3, 王宁1, 2, 3   

  1. 1. 农业部鸡遗传育种重点实验室,哈尔滨 150030;
    2. 黑龙江省普通高等学校动物遗传育种与繁殖重点实验室,哈尔滨 150030;
    3. 东北农业大学动物科学技术学院,哈尔滨 150030
  • 收稿日期:2016-03-08 修回日期:2016-04-11 出版日期:2016-08-20 发布日期:2016-05-23
  • 通讯作者: 王宁,博士,教授,博士生导师,研究方向:动物遗传育种。E-mail: wangning@neau.edu.cn E-mail:chengminneau@163.com
  • 作者简介:程敏,硕士研究生,专业方向:动物遗传育种。E-mail: chengminneau@163.com
  • 基金资助:
    国家自然科学基金项目(编号:31372299)和农业部产业体系项目(编号:CARS-42)资助

Functional analysis of the upstream regulatory region of chicken miR-17-92 cluster

Min Cheng1, 2, 3, Wenjian Zhang1, 2, 3, Tianyu Xing1, 2, 3, Xiaohong Yan1, 2, 3, Yumao Li1, 2, 3, Hui Li1, 2, 3, Ning Wang1, 2, 3   

  1. 1. Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture, Harbin 150030, China;
    2. Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, China;
    3. College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
  • Received:2016-03-08 Revised:2016-04-11 Online:2016-08-20 Published:2016-05-23
  • Supported by:
    Supported by the National Natural Science Foundation of China (No; 31372299) and the China Agriculture Research System (No; CARS-42)

摘要: miR-17-92基因簇(miR-17-92 cluster)在细胞增殖、分化、凋亡、动物发育以及肿瘤发生等过程中发挥重要作用。目前,人和小鼠等哺乳动物miR-17-92基因簇的转录调控已有深入研究,但该基因簇在鸡等鸟类中的转录调控研究还未见报道,主要原因在于鸟类miR-17-92基因簇上游的基因组序列都存在一个gap,且该基因簇启动子的位置和序列也还不清楚。为此,本研究采用染色体步移的方法获得鸡miR-17-92基因簇上游gap区序列,并采用生物信息学分析和报告基因及截短突变技术开展该gap区的功能分析。染色体步移分析发现,鸡miR-17-92基因簇上游gap区全长1704 bp,GC含量达80.11%。生物信息学分析显示,鸡miR-17-92基因簇上游gap区内1段200 bp的序列与人、牛、小鼠等9种动物miR-17-92基因簇上游序列保守性较高,且该区域为人和小鼠等哺乳动物miR-17-92基因簇宿主基因的核心启动子区。将克隆的gap区序列插入pGL3 basic荧光素酶报告基因载体,构建成启动子荧光素酶报告基因载体pGL3-cMIR17HG(-4228/-2506)。荧光素酶报告基因活性分析表明,pGL3-cMIR17HG(-4228/-2506)报告基因的活性是pGL3 basic空载体活性的417倍,证明所克隆的gap区片段是鸡miR-17-92基因簇宿主基因的启动子。为进一步分析该启动子的结构和功能,构建gap区片段的5°端缺失突变(缺失448 bp)和3°端缺失突变(缺失894 bp)的荧光素酶报告基因载体。与pGL3-cMIR17HG(-4228/-2506)相比,5°端和3°端缺失突变分别使启动子报告基因活性降低19.82%和60.14%。这些数据提示,鸡miR-17-92基因簇宿主基因启动子的重要调控区位于-3400/-2506。本研究结果为进一步开展鸡miR-17-92基因簇的转录调控奠定了基础。

关键词: 鸡, miR-17-92基因簇, 启动子, 转录调控

Abstract: miR-17-92 cluster plays important roles in cell proliferation, differentiation, apoptosis, animal development and tumorigenesis. The transcriptional regulation of miR-17-92 cluster has been extensively studied in mammals, but not in birds. To date, avian miR-17-92 cluster genomic structure has not been fully determined. The promoter location and sequence of miR-17-92 cluster have not been determined, due to the existence of a genomic gap sequence upstream of miR-17-92 cluster in all the birds whose genomes have been sequenced. In this study, genome walking was used to close the genomic gap upstream of chicken miR-17-92 cluster. In addition, bioinformatics analysis, reporter gene assay and truncation mutagenesis were used to investigate functional role of the genomic gap sequence. Genome walking analysis showed that the gap region was 1704 bp long, and its GC content was 80.11%. Bioinformatics analysis showed that in the gap region, there was a 200 bp conserved sequence among the tested 10 species (Gallus gallus, Homo sapiens, Pan troglodytes, Bos taurus, Sus scrofa, Rattus norvegicus, Mus musculus, Possum, Danio rerio, Rana nigromaculata), which is core promoter region of mammalian miR-17-92 host gene (MIR17HG). Promoter luciferase reporter gene vector of the gap region was constructed and reporter assay was performed. The result showed that the promoter activity of pGL3-cMIR17HG (-4228/-2506) was 417 times than that of negative control (empty pGL3 basic vector), suggesting that chicken miR-17-92 cluster promoter exists in the gap region. To further gain insight into the promoter structure, two different truncations for the cloned gap sequence were generated by PCR. One had a truncation of 448 bp at the 5′-end and the other had a truncation of 894 bp at the 3′-end. Further reporter analysis showed that compared with the promoter activity of pGL3-cMIR17HG (-4228/-2506), the reporter activities of the 5′-end truncation and the 3′-end truncation were reduced by 19.82% and 60.14%, respectively. These data demonstrated that the important promoter region of chicken miR-17-92 cluster is located in the -3400/-2506 bp region. Our results lay the foundation for revealing the transcriptional regulatory mechanisms of chicken miR-17-92 cluster.

Key words: chicken, miR-17-92 cluster, promoter, transcriptional regulation