中文摘要：

MicroRNA（miRNA）是一种长度约为22个碱基的非编码单链小分子RNA。作为一类重要的转录后基因表达调控因子,miRNA参与了广泛的生物学过程,如发育时程调控、细胞分化、凋亡、肿瘤以及病毒抵抗等。然而,除了在个体发生过程中的重要功能外,越来越多的研究表明,miRNA在系统发生中也扮演着关键的角色。基因表达模式的不同被广泛地认为是物种内和物种间表型差异的根源,动物物种间miRNA的保守性和多样性研究提示miRNA对物种间表型差异以及动物进化起着重要的作用。文章介绍了miRNA产生过程和作用机制,重点探讨了miRNA在动物进化过程中的作用,从miRNA的进化速度、miRNA表达的时空特异性、miRNA作用靶位点变异以及miRNA基因的扩增与丢失4个方面论述miRNA介导的基因调控网络对多细胞动物发育复杂性进化的影响,推测miRNA在多细胞动物进化过程中驱动了复杂性的增加。

英文摘要：

MicroRNAs （miRNAs） are a novel class of ～22 nt non-coding small RNAs. As crucial post-transcriptional regulators, miRNAs are involved in comprehensive biological processes such as developmental timing, cell proliferation and differentiation, oncogenesis and viral defenses. In addition to the roles in ontogenic physiology, researches on the area of miRNA phylogenetic conservation and diversity suggested that miRNAs play important roles in animal evolution through driving phenotypic variations in development. It has been postulated that miRNAs have enormous impacts on phenotypic variation and developmental complexity. Here we reviewed recent advances in the studies on the roles of miRNA in animal evolution, from aspects of the rate of miRNA evolution, the spatio-temporal expression pattern, the variation of tar-get sites, and miRNA gene dynamics. We gave evidence to support the hypothesis that innovations in miRNA-mediated regulations drive the increase of metazoan complexity.