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nature上一篇文章：qiRNA a new type of small interfering RNA【已搜索无重复】
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nature上一篇文章：qiRNA is a new type of small interfering RNA induced by DNA damage，前几天刚在论坛上看见关于PiRNA的一个帖子，今天看nature发现又一个新的小干扰RNA，与大家分享了~~把那篇关于PIRNA的也附上 http://www.namipan.com/d/04a7994 ... be2debd5ab2d79c0900 http://www.namipan.com/d/40173cd ... 099d3afb1f037d30600 呵呵 下载后不忘回个帖 给个评价哦 |
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2楼2009-05-22 15:34:19
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7楼2009-05-23 23:07:51
★★★ 三星级,支持鼓励
| qiRNA is a new type of small interfering RNA induced by DNA damage，这篇文章下载不了啊，能发到我邮箱吗？谢谢了！0209cy@163.com |
9楼2009-12-13 19:01:51
10楼2009-12-29 11:57:09
★ 一星级,一般
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my Paper trace: qiRNA is a new type of small interfering RNA induced by DNA damage //On the basis of our results, we propose that the production of qiRNAs is another mechanism that contributes to DNA damage checkpoints by inhibiting protein synthesis. Results obtained from higher eukaryotic organisms also indicate the importance of rDNA-derived small RNAs. // //In mouse embryonic stem cells, rRNA-specific small RNAs associated with a small RNA binding protein18. // //In Arabidopsis, RNAi components are found in the nucleolus and rDNA-specific small RNAs contribute to heterochromatin formation19. // //The Drosophila dicer-2 mutant exhibited disorganized nucleoli and rDNA, suggesting a role for the RNAi pathway in maintaining genome stability in the rDNA region20. // //Like qiRNA, some of the small RNAs from higher eukaryotes are also enriched in repetitive regions of the genome1. // //Our study raises the possibility that spontaneous DNA damage produced during recombination or transposon transposition could be a trigger to induce the production of small RNAs. // 1. Ghildiyal, M. & Zamore, P. D. Small silencing RNAs: an expanding universe. Nature Rev. Genet. 10, 94–108 (2009) 2. Calabrese, J. M. & Sharp, P. A. Characterization of the short RNAs bound by the P19 suppressor of RNA silencing in mouse embryonic stem cells. RNA 12, 2092–2102 (2006) 3. Pontes, O. et al. The Arabidopsis chromatin-modifying nuclear siRNA pathway involves a nucleolar RNA processing center. Cell 126, 79–92 (2006) 4. Peng, J. C. & Karpen, G. H. H3K9 methylation and RNA interference regulate nucleolar organization and repeated DNA stability. Nature Cell Biol. 9, 25–35 (2007) Characterization of the short RNAs bound by the P19 suppressor of RNA silencing in mouse embryonic stem cells //This large average difference in GC content was observed for both known ncRNAs and novel RNAs, indicating an overall preference of P19 for GC-rich RNA (Table 1).// //Unknown function of P19 bound short rRNAs Studies from S. pombe and Arabidopsis have implicated short rRNAs in the formation of heterochromatin at rDNA repeats, setting a precedent for short rRNA functionality (Xie et al. 2004; Cam et al. 2005). One common feature of these short rRNAs involved in chromatin silencing is that they are both sense and anti-sense to the full-length, transcribed rRNA, supporting the idea that they are generated from processing of a longer dsRNA precursor (Xie et al. 2004; Cam et al. 2005). In contrast, all but one of the short rRNAs cloned in this study were in the sense orientation relative to transcription of the mature rRNAs, suggesting that they arose either by breakdown or processing of mature rRNA sequence. However, this observation does not exclude a possible role for short rRNAs in the chromatin silencing of ES cell rDNA repeats. Recently, ncRNAs mapping directly upstream of the rDNA transcriptional start site have been shown to direct the nucleolar remodeling complex (NoRC) to transcriptionally silence rDNA repeats in mouse 3T3 cells (Mayer et al. 2006). No short RNAs cloned in this study map to this region of the rDNA repeat, consistent with the authors’ observation that the NoRC-associated RNAs are 150–300 nt long. P19V5 immunoprecipitates short RNAs from Dicer null ES cells as efficiently as from Dicer-containing cells, shown by 3'-end labeling of immunoprecipitated RNA (Fig. 4A). Similarly, short RNA Northern blots probing P19 immunoprecipitates for enriched short rRNA #3 show the same enrichment in the presence and absence of Dicer. Together, these results indicate that enriched rRNAs are generated independently of Dicer and are not by-products of P19 expression or transfection. We show that they exist in the absence of Dicer and do not function in endogenous PTGS, suggesting that they are not in the canonical RNAi pathway. In other organisms, short rRNAs have been implicated in the chromatin silencing of rDNA repeats (Xie et al. 2004; Cam et al. 2005); Nature 453, 534-538 (22 May 2008) Pseudogene-derived small interfering RNAs regulate gene expression in mouse oocytes //Abstract: Pseudogenes populate the mammalian genome as remnants of artefactual incorporation of coding messenger RNAs into transposon pathways1. Here we show that a subset of pseudogenes generates endogenous small interfering RNAs (endo-siRNAs) in mouse oocytes. These endo-siRNAs are often processed from double-stranded RNAs formed by hybridization of spliced transcripts from protein-coding genes to antisense transcripts from homologous pseudogenes. An inverted repeat pseudogene can also generate abundant small RNAs directly. A second class of endo-siRNAs may enforce repression of mobile genetic elements, acting together with Piwi-interacting RNAs. Loss of Dicer, a protein integral to small RNA production, increases expression of endo-siRNA targets, demonstrating their regulatory activity. Our findings indicate a function for pseudogenes in regulating gene expression by means of the RNA interference pathway and may, in part, explain the evolutionary pressure to conserve argonaute-mediated catalysis in mammals.// //These observations indicate that pseudogenes might not be purely dead relics of past genes but could be resurrected for new biochemical activities. Indeed, functioning pseudogenes have been reported previously. For instance, in snails, a pseudogene is involved in translational control of the gene that codes for nitric oxide synthase10. And transcripts of the mouse pseudogene makorin1-p1 have been proposed to inhibit degradation of their parent gene's mRNA, effectively enhancing its expression11, although this observation has been debated. Nevertheless, a clear mechanism for the functioning of pseudogenes has been lacking. The six studies — four in flies1, 2, 3, 4 and two in mice5, 6 — provide such a direct pathway, showing that pseudogene transcripts can act as natural siRNAs.// |
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剪纸艺术8楼
2009-12-13 14:48
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sdgxxty12楼
2009-12-29 14:57
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yinhuan13楼
2009-12-29 15:13
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谢谢分享
limengfei14楼
2010-01-22 17:10
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