Sutton C A, Conklin P L, Pruitt K D, Hanson M R
Section of Genetics and Development, Cornell University, Ithaca, New York 14853-2703.
Mol Cell Biol. 1991 Aug;11(8):4274-7. doi: 10.1128/mcb.11.8.4274-4277.1991.
Plant mitochondrial mRNAs have recently been shown to undergo editing, involving cytidine-to-uridine changes relative to the DNA sequence. We have examined the temporal relationship of editing and intron removal in coxII mRNAs in Petunia mitochondria. By using differential hybridization to probes specific for edited and unedited RNA and by sequencing of individual unspliced coxII pre-mRNA cDNAs, we found that RNA editing at any editing site can precede the splicing event. Similar results were obtained from examinations of pre-mRNA cDNAs of nad1, a gene composed of multiple exons that are both cis and trans spliced. Thus, intron removal is not required before editing can occur. The existence of editing intermediates indicates that the editing process is not strictly coincident with transcription.
最近研究表明，植物线粒体信使核糖核酸（mRNA）会发生编辑，相对于DNA序列而言，涉及胞嘧啶到尿嘧啶的变化。我们研究了矮牵牛属线粒体中细胞色素氧化酶亚基II（coxII）mRNA编辑与内含子去除的时间关系。通过使用针对编辑和未编辑RNA的特异性探针进行差异杂交，以及对单个未剪接的coxII前体mRNA cDNA进行测序，我们发现任何编辑位点的RNA编辑都可以先于剪接事件发生。对烟酰胺腺嘌呤二核苷酸脱氢酶亚基1（nad1）的前体mRNA cDNA进行检测也得到了类似结果，nad1是一个由多个外显子组成的基因，这些外显子既有顺式剪接也有反式剪接。因此，在编辑发生之前不需要去除内含子。编辑中间体的存在表明编辑过程与转录并非严格同步。
