紫茎泽兰叶绿体基因RNA编辑位点的鉴定及分析
Identification and Analysis of RNA Editing Sites in the Chloroplast Transcripts of Ageratina adenophora

RNA编辑是陆生植物叶绿体转录后基因表达调控的一种重要方式。本试验以紫茎泽兰为材料，利用生物信息学预测结合分子克隆及测序方法对其叶绿体的RNA编辑位点进行预测和分析。结果共预测到分布于19个基因的42个编辑位点，所有位点均为C到U的转换。编辑位点的发生位置分析发现，8个位于密码子第1位，34个位于密码子第2位，而密码子第3位未发现RNA编辑事件。同时，利用RT-PCR方法对其中4个基因的编辑位点进行验证，鉴定发现10个真实发生的编辑位点。进一步分析这10个位点发生编辑后对其编码蛋白质跨膜结构域和二级结构的影响，结果表明， ndhB-467的编辑会引起蛋白质跨膜结构的增加， ndhB-149的编辑会引起蛋白质二级结构的改变。
RNA editing is an important approach to regulate the gene expression at post-transcriptional levels in chloroplast transcript in terrestrial plants. This paper predicted and analyzed the RNA editing sites in the cp genome of A.adenophora using the Prep-Cp and CURE tools with molecular cloning and sequencing methods. Forty-two editing sites were identified and distributed in 19 protein-coding genes, of which all were C to U conversion. Among them, 8 RNA editing sites occurred in the first position of codons, and the rest 34 sites occurred in the second position of codons. No RNA editing sites were detected in the third position of codon. Four genes and ten editing sites actual existed. Finally, the second structures and the transmembrane domains of these proteins were also analyzed using bioinformatics methods to identify the effect of the editing. Results indicated that ndhB-467 editing can cause an increase in transmembrane protein domains while editing in ndhB-149 will change the secondary structure.