摘 要：摘 要：microRNAs (miRNAs)是生物体内源长度约为20－23个核苷酸的非编码小RNA，通过与靶mRNA的互补配对而在转录后水平上对基因的表达进行负调控，导致mRNA的降解或翻译抑制。到目前为止，已报道有几千种miRNA存在于动物、植物、真菌等多细胞真核生物中，进化上高度保守。在植物和动物中，miRNA虽然都是通过与其靶基因的相互作用来调节基因表达，进而调控生物体的生长发育，但miRNA执行这种调控作用的机理却不尽相同。同时miRNA在动植物体内的形成过程也存在很多的不同之处。本文综述了动植物miRNA的生物合成、作用机理、生物功能等方面的研究进展。
关键词：植物；动物；miRNA；转录后基因沉默
Abstract: Abstract: MicroRNAs (miRNAs) are a class of endogenous noncoding single-stranded RNA with about 22-23 nucleotides length. MicroRNA function as sequence-specific negative regulators in post-transcriptional gene silencing by base pairing with target mRNAs, which leads to mRNA cleavage or translational repression. Several thousands of miRNAs have been reported by far in multicellular eukaryotes as diverse as animals，plants and fungi，which are conserved during evolution. Although miRNAs regulate gene expression by the interaction with their targeted mRNAs and then regulate the growth and development of plants and animals，the mechanism is very different in plants and animals. Meantime，there are also many differences in the biogenesis of miRNAs in plants and animals. This review highlights recent findings on the differences of the miRNA biogenesis，molecular mechanism and biological functions in plants and animals.
Key words: plant；animal；miRNA；post-transcriptional gene silencing
