哺乳動(dòng)物基因組被轉(zhuǎn)錄而產(chǎn)生無(wú)數(shù)大型非編碼RNA,，但它們的功能不清楚，主要是因?yàn)檫@些轉(zhuǎn)錄體很少或沒(méi)有演化保守性的證據(jù),。
現(xiàn)在,，一種對(duì)這些神秘分子進(jìn)行定性的新方法推動(dòng)了這一領(lǐng)域的發(fā)展。該方法不是以RNA分子本身為目標(biāo),，相反,，它們的存在表現(xiàn)為四種小鼠細(xì)胞類型的DNA中的染色質(zhì)修飾或表觀基因組標(biāo)記。用該方法進(jìn)行的搜索工作產(chǎn)生了超過(guò)1000個(gè)多外顯子轉(zhuǎn)錄單元,，它們與已知的蛋白編碼位點(diǎn)不重疊,，具有高度保守性。
這些“大型干涉性非編碼RNA”（lincRNAs）中的每一個(gè),，都可能有從胚胎干細(xì)胞多能性到細(xì)胞增殖在內(nèi)的一定功能,。特定lincRNAs是由在包括p53、NFKB、Sox2,、Oct4和Nanog在內(nèi)的過(guò)程中起關(guān)鍵作用的轉(zhuǎn)錄因子調(diào)控的,，而且這些lincRNAs中大多數(shù)在不同哺乳動(dòng)物中都保留了下來(lái)。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 458, 223-227 (12 March 2009) | doi:10.1038/nature07672
Chromatin signature reveals over a thousand highly conserved large non-coding RNAs in mammals
Mitchell Guttman1,2, Ido Amit1, Manuel Garber1, Courtney French1, Michael F. Lin1, David Feldser3, Maite Huarte1,6, Or Zuk1, Bryce W. Carey2,8, John P. Cassady2,8, Moran N. Cabili7, Rudolf Jaenisch2,8, Tarjei S. Mikkelsen1,4, Tyler Jacks2,3, Nir Hacohen1,9, Bradley E. Bernstein1,10,11, Manolis Kellis1,5, Aviv Regev1,2, John L. Rinn1,6,11,12 & Eric S. Lander1,2,7,8,12
1 Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA
2 Department of Biology,
3 The Koch Institute for Integrative Cancer Research,
4 Division of Health Sciences and Technology, and,
5 Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
6 Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
7 Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02114, USA
8 Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
9 Center for Immunology and Inflammatory Diseases,
10 Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
11 Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
12 These authors contributed equally to this work.
Correspondence to: John L. Rinn1,6,11,12 Correspondence and requests for materials should be addressed to J.L.R
There is growing recognition that mammalian cells produce many thousands of large intergenic transcripts1, 2, 3, 4. However, the functional significance of these transcripts has been particularly controversial. Although there are some well-characterized examples, most (>95%) show little evidence of evolutionary conservation and have been suggested to represent transcriptional noise5, 6. Here we report a new approach to identifying large non-coding RNAs using chromatin-state maps to discover discrete transcriptional units intervening known protein-coding loci. Our approach identified 1,600 large multi-exonic RNAs across four mouse cell types. In sharp contrast to previous collections, these large intervening non-coding RNAs (lincRNAs) show strong purifying selection in their genomic loci, exonic sequences and promoter regions, with greater than 95% showing clear evolutionary conservation. We also developed a functional genomics approach that assigns putative functions to each lincRNA, demonstrating a diverse range of roles for lincRNAs in processes from embryonic stem cell pluripotency to cell proliferation. We obtained independent functional validation for the predictions for over 100 lincRNAs, using cell-based assays. In particular, we demonstrate that specific lincRNAs are transcriptionally regulated by key transcription factors in these processes such as p53, NFB, Sox2, Oct4 (also known as Pou5f1) and Nanog. Together, these results define a unique collection of functional lincRNAs that are highly conserved and implicated in diverse biological processes.
