Abstract: MicroRNAs (miRNAs), a class of small non-coding RNAs in animals, plants, fungi and viruses, regulate the gene expression at post-transcriptional level through translational repression or mRNA degradation. A large number of miRNAs have been reported in insects, but the number of miRNAs with documented functions is limited. During insect metamorphosis, let-7, miR-100, miR-125, miR-34, miR-14, miR-8, miR-281 and miR-252-3p have been demonstrated to function in juvenile hormone and/or ecdysone mediated signaling pathways and to modulate the development of wings, legs and neuronal system. In insect reproduction, bantam, miR-184 and miR-275 have been found to regulate the differentiation and maintenance of female germ line cells as well as the oogenesis. We summarized here the recent advances in the roles of miRNAs in insect metamorphosis and reproduction.

Key words: miRNA, biosynthesis, post-transcriptional regulation, insect metamorphosis, insect reproduction