本期《Science》两篇论文通过观测部分小鼠基因组从DNA到RNA的转录,为哺乳动物基因组的复杂性提供了详细的描述。这项研究旨在确定DNA到RNA转录的起始和终止位置,它证实也扩展了最近一些工作提出的转录过程具有高度变化性的观点。这个大的国际研究组还找到了新的编码蛋白和非编码的转录物,并发现非编码转录物比过去认为的要多。一篇相关的“观点”文章的作者写道,“小鼠基因组中令人惊讶的62%被转录”,在研究人员找到的181000个独立的RNA转录物中,约一半为非编码RNA。在制造RNA过程中,从模板DNA转录的那链被称为“有义链”,另外那链被称为“反义链”。两篇新论文中的第二篇提出,反义转录比过去的研究所估计的要常见得多。这些研究人员报告说,70%以上的测绘出的RNA转录单元,与来自DNA的相对应链的转录物有某种程度的重复。
Science Magazine and its online Knowledge Environments weave through the multilayered world of RNA in a special collection of articles published with the 2 September 2005 issue. In Science, Review and Viewpoint articles cover the relationship between RNA structure and function, the emerging "big world" of small RNAs, noncoding RNAs, and other aspects of this remarkable molecule; also in the issue are eleven new research papers touching various aspects of RNA. In addition, an accompanying pull-out poster limns the role of small RNAs in gene silencing. Science's Signal Transduction Knowledge Environment presents articles and an animation further exploring the roles of RNA in genomic complexity and regulation of gene expression. And the Science of Aging Knowledge Environment looks at how RNA interference has affected aging research in a key model system, the worm.
Poster: RNA Silencing
A downloadable PDF version of the pull-out poster (sponsored by Ambion) featured in this special issue.