一項搜索線蟲能夠增強對外源雙螺旋RNA（dsRNA）反應(yīng)的突變的研究工作,，獲得了一個令人吃驚的發(fā)現(xiàn)：一個RNA干涉基因是通過其兩個構(gòu)成部分經(jīng)一個dsRNA中間體進行的反式剪接組裝成的。
這樣所獲得的基因的產(chǎn)物是解旋酶ERI-6/7,，其功能是充當外源和內(nèi)源RNAi的一個負調(diào)控因子,。
這是后生動物中反式剪接的極少幾個例子之一,，而且還是一個RNAi因子如此被調(diào)控的第一個例子（后者也許還有重要意義）,。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
