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miRNAs触发广泛的表观遗传激活的siRNAs来自Arabidopsis中的转位子
Kate M Creasey1, Jixian Zhai2, Filipe Borges1
1Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA.
Nature
|March 28, 2014
概括
植物利用微RNAs (miRNAs) 通过表观遗传激活的小干扰RNAs (easiRNAs) 沉默转位子. 这种miRNA指导的easiRNA途径准了重新激活的转体子,揭示了潜在的基因组防御机制.
科学领域:
- 植物分子生物学 植物分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 这是一种RNA干扰.
背景情况:
- 在植物中,转录后基因沉默 (PTGS) 涉及DCL1-依赖的微RNA (miRNA) 和二次小干扰RNA (siRNA).
- 转录基因沉默 (TGS) 的转体子依赖于24核酸异染色siRNAs (het-siRNAs).
- 表观遗传激活的siRNAs (easiRNAs) 在特定的突变物和植物组织中很丰富,准转子子转录.
研究的目的:
- 为了研究Arabidopsis thaliana中easiRNAs的生物发生和功能.
- 为了阐明miRNA指导的easiRNA生产和转子子沉默之间的关系.
- 了解easiRNAs在基因组防御和转子子调节中的作用.
主要方法:
- 在Arabidopsis thaliana突变体 (ddm1, met1) 中对easiRNA生成的分析.
- 使用小RNA测序来识别和量化easiRNAs和het-siRNAs.
- 研究关键RNA沉默通路组件 (RDR6,DCL4,DCL1) 在easiRNA生物发生中的作用.
主要成果:
- 成千上万的转子子转录被50多个miRNA准,由RDR6进行分裂和处理,产生easiRNAs.
- 在ddm1背景下RDR6,DCL4或DCL1的损失会消除easiRNAs并导致严重的不孕症.
- 在这些突变中,24-核酸-siRNAs被部分恢复,这表明PTGS和TGS之间存在敌对关系.
结论:
- miRNA指导的easiRNA生物发生是一种潜伏的机制,针对表观遗传上重新激活的转位子,特别是在生殖系重编程期间.
- 这条途径代表了转子子控制的古老识别机制,可能被转子子和宿主保留.
- 这些发现强调了PTGS和TGS在保持基因组稳定性方面的关键相互作用.
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