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RNA干涉与基因沉默 总被引:28,自引:6,他引:28
双链RNA介导的遗传干涉的机制是1998年发现的,它通过双链RNA的介导特异性地降解相应序列的mRNA,从而导致转录后水平的基因沉默,到目前为止的真菌,拟南芥,线虫,锥虫,水螅,涡虫,果蝇,斑马鱼,小鼠等真核生物中都发现存在这一基因沉默机制,目前的研究表明,RNA干涉与植物中的共抑制(Cosuppression),真菌中的基因压制(quelling)很可能具有共同的基本分子机制,这也说明,很可能在进化的很早期阶段,生物就获得了这种机制,RNA干涉对于抵抗病毒入侵,抑制转座子活动等具有重要作用,对于生物体的发育和基因调控可能也有重要作用。 相似文献
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RNA干涉的研究进展 总被引:34,自引:0,他引:34
生物体内导入双链RNA后会引起体内同源基因特异性的沉默,这种现象称为RNA干涉,本主要介绍RNA干涉的研究历史,作用机制和应用等方面的情况。 相似文献
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RNA干扰抗病毒研究进展 总被引:4,自引:1,他引:3
RNA干扰(RNA Interfering,RNAi),又称RNA干涉,是一种由双链RNA介导的、转录后mRNA水平关闭相应基因表达的序列特异性基因沉默机制,它也是体内基因组抵御外在感染和内部转座的一种保护机制,广泛存在于各种生物,如植物、真菌、昆虫、后生动物和哺乳动物,包括人类。 相似文献
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RNA干涉分子机制研究进展 总被引:13,自引:0,他引:13
RNA干涉(RNA interference,RNAi)是生物体内的一种通过双链RNA(dsRNA)来抵抗病毒入侵和抑制转座子活动的自然机制.双链RNA与同源mRNA互补结合而使特定基因失活,这一过程已经在包括拟南芥、线虫和真菌等多种模式生物中得到揭示.近来研究表明,21~25 nt的小干涉RNA(small interference RNA, siRNA)可介导哺乳动物细胞特异性基因沉默.RNAi具有高效性和高度特异性,可能成为关闭基因的新技术而在基因功能研究和疾病基因治疗中发挥重要作用. 相似文献
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COS-7细胞中小发卡RNA介导的RNA干涉 总被引:3,自引:0,他引:3
利用U6启动子转录小发卡RNA介导的RNA干涉是最近发展起来的在哺乳动物细胞中特异性抑制指定基因表达的新技术,已有实验证明它在小鼠畸胎瘤P19等细胞系中具有强烈的抑制基因表达的作用。本文对COS-7细胞系中U6启动子转录GFP基因的小发卡RNA介导的RNA干涉现象进行了研究,结果表明:U6启动子转录的小发卡RNA具有RNA干涉作用,即可以在COS-7细胞中特异性地抑制含有对应序列的基因GFP的表达,这一结果为今后在COS-7细胞系中利用RNA干涉技术研究目的基因的功能奠定了基础。 相似文献
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基因捕捉及其在植物基因分离和功能基因组学上的应用 总被引:3,自引:0,他引:3
基因捕捉是一种报告基因的随机整合技术。基因捕捉系统已成为分离基因、鉴定基因功能的重要手段。基因捕捉(gene traps)包括增强子捕捉(enhancer trap)、启动子捕捉(promoter trap)和基因捕捉(gene trap),通称为基因捕捉(gcne traps)。在增强子捕捉中,报告基因与一个基本启动子融合,这个启动子不能使报告基因表达,但可被临近的增强子激活。在启动子捕捉和基因捕捉中,报告基因的启动子被去除,融合基因只有以正确的方向插入到转录单元内才能表达。对基因捕捉系统的结构特征、构建方法、应用范围、研究现状和应用前景等作了系统论述,并对有关问题进行了讨论。 相似文献
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Gene set analysis allows the inclusion of knowledge from established gene sets, such as gene pathways, and potentially improves the power of detecting differentially expressed genes. However, conventional methods of gene set analysis focus on gene marginal effects in a gene set, and ignore gene interactions which may contribute to complex human diseases. In this study, we propose a method of gene interaction enrichment analysis, which incorporates knowledge of predefined gene sets (e.g. gene pathways) to identify enriched gene interaction effects on a phenotype of interest. In our proposed method, we also discuss the reduction of irrelevant genes and the extraction of a core set of gene interactions for an identified gene set, which contribute to the statistical variation of a phenotype of interest. The utility of our method is demonstrated through analyses on two publicly available microarray datasets. The results show that our method can identify gene sets that show strong gene interaction enrichments. The enriched gene interactions identified by our method may provide clues to new gene regulation mechanisms related to the studied phenotypes. In summary, our method offers a powerful tool for researchers to exhaustively examine the large numbers of gene interactions associated with complex human diseases, and can be a useful complement to classical gene set analyses which only considers single genes in a gene set. 相似文献
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Dietrich MR 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》2000,323(12):1139-1146
During the early 20th century the diverse practices of genetics were unified by the concept of the gene. This classical gene was simultaneously a unit of structure, function, mutation, and recombination. Starting in the 1940s, however, the classical gene began to fragment. Today when we speak of a gene for some malady, a regulatory gene, a structural gene, or a gene frequency, it is entirely possible that we are deploying different gene concepts even though we are using the same term. The problem of the gene addresses the fragmentation of the classical gene concept by asking to what extent a comprehensive and unifying gene concept is possible or desirable. Fully comprehensive gene concepts seem untenable today, but, within different disciplinary domains, unifying, but non-comprehensive, gene concepts can be epistemically worthwhile. The problem of the gene persists, however, not because of its epistemic value, but because of its political value. Using both the arguments for newly proposed gene concepts and the historical dispute over the classical gene, I argue that the desirability of gene concepts rests in part on the political ramifications of their deployment and contestation. 相似文献
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The balhimycin biosynthetic gene cluster of the glycopeptide producer Amycolatopsis balhimycina includes a gene (orf1) with unknown function. orf1 shows high similarity to the mbtH gene from Mycobacterium tuberculosis. In almost all nonribosomal peptide synthetase (NRPS) biosynthetic gene clusters, we could identify a small mbtH-like gene whose function in peptide biosynthesis is not known. The mbtH-like gene is always colocalized with the NRPS genes; however, it does not have a specific position in the gene cluster. In all glycopeptide biosynthetic gene clusters the orf1-like gene is always located downstream of the gene encoding the last module of the NRPS. We inactivated the orf1 gene in A. balhimycina by generating a deletion mutant. The balhimycin production is not affected in the orf1-deletion mutant and is indistinguishable from that of the wild type. For the first time, we show that the inactivation of an mbtH-like gene does not impair the biosynthesis of a nonribosomal peptide. 相似文献
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渐狭叶烟草(Nicotiana attenuata)是烟草属植物中研究植物与昆虫、植物与病原菌互作的模式植物。本研究以八氢番茄红素脱氢酶基因(PDS)为靶标基因,建立一套以pHSE401为基因编辑载体,以潮霉素为抗性筛选标记的渐狭叶烟草高效基因编辑体系。利用该体系,获得PDS基因约80%的基因编辑效率,远远超过目前在渐狭叶烟草中报道的约30%的基因编辑效率。进一步使用WRKY70基因为靶标,对该体系对进行编辑效率验证,经测序发现WRKY70基因编辑材料中的基因编辑效率为83%,其中发生大片段缺失突变的频率为50%。因此,本研究成功建立了渐狭叶烟草高效基因编辑体系,为以后渐狭叶烟草的基因功能研究奠定基础。 相似文献
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ROBERT F. ALINE JR. PETER J. MYLER ELKE GOBRIGHT KENNETH D. STUART 《The Journal of eukaryotic microbiology》1994,41(1):71-78
Intrachromosomal variant surface glycoprotein (VSG) genes in Trypanosoma brucei are expressed by a mechanism involving gene conversion. The 3'boundary of gene conversion is usually within the last 130 bp of the VSG gene, a region of partially conserved sequences. We report here the loss of the predominant telomeric A VSG gene in the cloned variant antigenic type (VAT) 5A3 , leaving only an intrachromosomal A VSG gene (the A-B gene). The nucleotide sequence of the A-B VSG gene reveals that it lacks the normal VSG 3' sequence. Surprisingly, we find cells expressing this A-B VSG gene in relapse populations arising from VAT 5A3 . Since the A VSG mRNAs from these cells have a normal 3' sequence, the incomplete A-B VSG gene must be expressed via a partial gene conversion that supplies the functional 3'end. Although the A-B VSG gene is no longer predominant like the telomeric A VSG gene, it is still expressed more frequently than other intrachromosomal VSG genes, suggesting that factors other than a telomeric location determine whether a VSG gene is expressed early in a serodeme. 相似文献
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利用套叠PCR技术进行基因突变和拼接 总被引:11,自引:4,他引:11
利用套叠PCR技术(又称重叠区扩增基因拼接法)对hGM-CSF基因内第28位氨基酸处的糖基化位点进行突变和进行人促性腺激素基因,腺苷酸激酶短肽与胰岛素样生长因子-基因三者之间的拼接,结果表明采用该技术能在体外实行有效的基因重组和定点突变,其成功率为100%,这一技术不需要内切酶消化和连接酶处理,技术操作员简单易行,在基因拼接,基因内部突变方面具有良好的应用价值。 相似文献