生物谷報(bào)道：在6月11日的PNAS網(wǎng)絡(luò)版上,，來(lái)自哈佛大學(xué)分子和細(xì)胞生物學(xué)系的研究人員發(fā)表的論文證實(shí)秀麗隱桿線蟲(Caenorhabditis elegans)SID-2是環(huán)境RNA干擾(RNAi)所必須的,。
在植物和線蟲（秀麗隱桿線蟲）中，一種RNAi信號(hào)能夠引發(fā)細(xì)胞中遠(yuǎn)距離位點(diǎn)的基因沉默,。而且,，在線蟲中,，環(huán)境中或其吞食的細(xì)菌中表達(dá)的dsRNA足以音符RNAi,即環(huán)境RNAi dsRNA的攝入和吞食在其他無(wú)脊椎動(dòng)物中也曾有過(guò)描述,。在哈佛的這項(xiàng)新研究中，研究人員確定并分析了SID-2（一種腸道luminal跨膜蛋白質(zhì)）是線蟲中發(fā)生環(huán)境RNAi所必須的,。當(dāng)在不發(fā)生環(huán)境RNAi的線蟲種（Caenorhabditis briggsae）中表達(dá)SID-2時(shí),，能夠使這種線蟲擁有了環(huán)境RNAi。
原始出處:
Published online before print June 11, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0611282104
Genetics
Caenorhabditis elegans SID-2 is required for environmental RNA interference
( dsRNA | transmembrane | intestine lumen )
William M. Winston *, Marie Sutherlin , Amanda J. Wright , Evan H. Feinberg , and Craig P. Hunter ¶
Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138
Edited by Iva S. Greenwald, Columbia University, New York, NY, and approved March 6, 2007 (received for review December 19, 2006)
Abstract
In plants and in the nematode Caenorhabditis elegans, an RNAi signal can trigger gene silencing in cells distant from the site where silencing is initiated. In plants, this signal is known to be a form of dsRNA, and the signal is most likely a form of dsRNA in C. elegans as well. Furthermore, in C. elegans, dsRNA present in the environment or expressed in ingested bacteria is sufficient to trigger RNAi (environmental RNAi). Ingestion and soaking delivery of dsRNA has also been described for other invertebrates. Here we report the identification and characterization of SID-2, an intestinal luminal transmembrane protein required for environmental RNAi in C. elegans. SID-2, when expressed in the environmental RNAi defective species Caenorhabditis briggsae, confers environmental RNAi.
Fig. 1. sid-2 worms are capable of spreading transgene-initiated RNAi. (A)Wild-type expression of GFP in the pharynx (ph) (myo-2::gfp) and body-wall muscle nuclei (bm) (myo-3::gfp) of an HC46 worm. (B) Expression of dsRNA (myo-2::gfp) in the pharynx causes incomplete silencing of pharynx and body-wall muscle GFP in the HC57 strain. (C)Asid-2(qt13)wormexpressing the same transgenes as HC57 is capable of spreading transgene-initiated RNAi from the pharynx to the body-wall muscle. GFP images were taken at equal exposures. Anterior is upper left. (Scale bar, 0.1 mm.)
