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我们以往的研究证明水稻受病原菌诱导的Rim2/Hipa 因子是水稻基因组所特有的 DNA 转座子超级家族。本实验通过对病原菌诱导的 cDNA文库的筛选和对 EST 数据库的搜索,发现在众多的 Rim2 拷贝中,只有 Rim2-42 因子被表达,其为一个TNP2类转座酶的假基因,其编码区为终止子所打断。序列分析结果表明Rim2转录本被选择性剪接和加尾,而且在两个水稻亚种中的剪接方式有差异,共形成 7 种不同转录本结构,包括一个未知功能的Rim2-XET嵌合转录本,该嵌合转录本为转录通读(read-through)所形成,而 XET 基因是可以被逆境所诱导的。这些结果说明Rim2因子家族可能已失去转座的活性。结果也初步表明Rim2-42 因子插入到了一个 XET 基因启动子的下游,该启动子带动了 Rim2 因子的诱导表达。
Our previous studies demonstrated that Rim2 / Hipa, a rice-induced pathogen, is a rice transposon superfamily that is unique to the rice genome. In this experiment, screening of pathogen-induced cDNA library and search of EST database showed that among many Rim2 copies, only Rim2-42 was expressed, which is a pseudotyped gene of TNP2 transposase with a coding region of Terminator interrupted. Sequence analysis showed that the Rim2 transcripts were selectively spliced and tailed, and there were differences in splicing patterns in two rice subspecies, forming seven different transcript structures, including an unknown function Rim2-XET chimeric transcript , The chimeric transcript is formed by read-through and the XET gene can be induced by stress. These results indicate that the Rim2 factor family may have lost transposition activity. The results also showed that the Rim2-42 gene was inserted downstream of the promoter of XET gene, which led to the inducible expression of Rim2.