Pontes Olga, Pikaard Craig S
Biology Department, Washington University, 1 Brookings Drive, St. Louis, MO 63130, USA.
Curr Opin Genet Dev. 2008 Apr;18(2):197-203. doi: 10.1016/j.gde.2008.01.008. Epub 2008 Mar 11.
In diverse eukaryotes, micro-RNAs (miRNAs) and small interfering RNAs (siRNAs) regulate important processes that include mRNA inactivation, viral defense, chromatin modification, and transposon silencing. Recently, nucleolus-associated Cajal bodies in plants have been implicated as sites of siRNA and miRNA biogenesis, whereas in animals siRNA and miRNA dicing occurs in the cytoplasm. The plant nucleolus also contains proteins of the nonsense-mediated mRNA decay pathway that in animals are found associated with cytoplasmic processing bodies (P-bodies). P-bodies also function in the degradation of mRNAs subjected to miRNA and siRNA targeting. Collectively, these observations suggest interesting variations in the way siRNAs and miRNAs can accomplish their similar functions in plants and animals.
在多种真核生物中，微小RNA（miRNA）和小干扰RNA（siRNA）调控着包括mRNA失活、病毒防御、染色质修饰和转座子沉默在内的重要过程。最近，植物中与核仁相关的卡哈尔体被认为是siRNA和miRNA生物合成的场所，而在动物中，siRNA和miRNA的切割发生在细胞质中。植物核仁还含有无义介导的mRNA降解途径的蛋白质，而在动物中，这些蛋白质与细胞质加工小体（P小体）相关。P小体也在受miRNA和siRNA靶向的mRNA降解中发挥作用。总的来说，这些观察结果表明，siRNA和miRNA在植物和动物中实现其相似功能的方式存在有趣的差异。
