一项搜索线虫能够增强对外源双螺旋RNA（dsRNA）反应的突变的研究工作，获得了一个令人吃惊的发现：一个RNA干涉基因是通过其两个构成部分经一个dsRNA中间体进行的反式剪接组装成的。
这样所获得的基因的产物是解旋酶ERI-6/7，其功能是充当外源和内源RNAi的一个负调控因子。
这是后生动物中反式剪接的极少几个例子之一，而且还是一个RNAi因子如此被调控的第一个例子（后者也许还有重要意义）。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 455, 491-496 (25 September 2008) | doi:10.1038/nature07274
Trans-splicing in C. elegans generates the negative RNAi regulator ERI-6/7
Sylvia E. J. Fischer1,2, Maurice D. Butler1,2, Qi Pan1,3 & Gary Ruvkun1
1 Department of Molecular Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114, USA
2 These authors contributed equally to this work.
Mutations that enhance the response to double-stranded RNA (dsRNA) have revealed components of the RNA interference (RNAi) pathway or related small RNA pathways. To explore these small RNA pathways, we screened for Caenorhabditis elegans mutants displaying an enhanced response to exogenous dsRNAs. Here we describe the isolation of mutations in two adjacent, divergently transcribed open reading frames (eri-6 and eri-7) that fail to complement. eri-6 and eri-7 produce separate pre-messenger RNAs (pre-mRNAs) that are trans-spliced to form a functional mRNA, eri-6/7. Trans-splicing of eri-6/7 is mediated by a direct repeat that flanks the eri-6 gene. Adenosine to inosine editing within untranslated regions of eri-6 and eri-7 pre-mRNAs reveals a double-stranded pre-mRNA intermediate, forming in the nucleus before splicing occurs. The ERI-6/7 protein is a superfamily I helicase that both negatively regulates the exogenous RNAi pathway and functions in an endogenous RNAi pathway.
