RNA as a target of double-stranded RNA-mediated genetic interference in Caenorhabditis elegans
RNA as a target of double-stranded RNA-mediated genetic interference in Caenorhabditis elegans
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DOI：
10.1073/pnas.95.26.15502
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发表时间：
1998-12-22
影响因子：
11.1
通讯作者：
Fire, A
中科院分区：
文献类型：
--
作者：
Montgomery, MK;Xu, SQ;Fire, A
外源性双链RNA（dsRNA）导入秀丽隐杆线虫（Caelophabditis elegans）后，可特异性地、有效地干扰含有同源序列的基因的活性。首先，我们检查了dsRNA介导的干扰后的主要DNA序列，没有发现改变的证据。第二，我们发现，dsRNA介导的干扰上游基因的极性操纵子的下游基因的活性没有影响，这一发现反对的转录的启动或延长的影响。第三，我们通过原位杂交观察到，dsRNA介导的干扰产生了大量的，但不完全的，减少在细胞核中的新生转录本的积累，而转录本的细胞质积累几乎被消除。这些结果表明，内源性mRNA是干扰的靶标，并表明在翻译发生之前降解靶向RNA的机制。该机制不依赖于C.负责锁定和摧毁异常信息的优雅生物。我们提出了一个模型，dsRNA如何可能在催化机制中发挥作用，以靶向同源mRNA降解。
Introduction of exogenous double-stranded RNA (dsRNA) into Caenorhabditis elegans has been shown to specifically and potently disrupt the activity of genes containing homologous sequences, In this study we present evidence that the primary interference effects of dsRNA are posttranscriptional. First, we examined the primary DNA sequence after dsRNA-mediated interference and found no evidence for alterations. Second, we found that dsRNA-mediated interference with the upstream gene in a polar operon had no effect on the activity of the downstream gene; this finding argues against an effect on initiation or elongation of transcription. Third, we observed by in situ hybridization that dsRNA-mediated interference produced a substantial, although not complete, reduction in accumulation of nascent transcripts in the nucleus, while cytoplasmic accumulation of transcripts was virtually eliminated. These results indicate that the endogenous mRNA is the target for interference and suggest a mechanism that degrades the targeted RNA before translation can occur. This mechanism is not dependent on the SMG system, an mRNA surveillance system in C. elegans responsible for targeting and destroying aberrant messages. We suggest a model of how dsRNA might function in a catalytic mechanism to target homologous mRNAs for degradation.