Rose Alan B, Elfersi Tali, Parra Genis, Korf Ian
Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
Plant Cell. 2008 Mar;20(3):543-51. doi: 10.1105/tpc.107.057190. Epub 2008 Mar 4.
Introns that elevate mRNA accumulation have been found in a wide range of eukaryotes. However, not all introns affect gene expression, and direct testing is currently the only way to identify stimulatory introns. Our genome-wide analysis in Arabidopsis thaliana revealed that promoter-proximal introns as a group are compositionally distinct from distal introns and that the degree to which an individual intron matches the promoter-proximal intron profile is a strong predictor of its ability to increase expression. We found that the sequences responsible for elevating expression are dispersed throughout an enhancing intron, as is a candidate motif that is overrepresented in first introns and whose occurrence in tested introns is proportional to its effect on expression. The signals responsible for intron-mediated enhancement are apparently conserved between Arabidopsis and rice (Oryza sativa) despite the large evolutionary distance separating these plants.
在多种真核生物中都发现了能提高信使核糖核酸（mRNA）积累量的内含子。然而，并非所有内含子都会影响基因表达，目前直接检测是识别具有刺激作用内含子的唯一方法。我们对拟南芥进行的全基因组分析表明，近端启动子内含子作为一个整体，在组成上与远端内含子不同，而且单个内含子与近端启动子内含子特征的匹配程度是其增加表达能力的有力预测指标。我们发现，负责提高表达的序列分散在一个增强型内含子中，在首个内含子中过度富集的一个候选基序也是如此，其在测试内含子中的出现频率与其对表达的影响成正比。尽管拟南芥和水稻（Oryza sativa）在进化上距离遥远，但负责内含子介导增强作用的信号在这两种植物之间显然是保守的。
