Progress on the research of microRNAs and its function in humans and animals

MicroRNAs,a class of noncoding RNA of approximately 22 nucleotides,can regulate gene expression by bind-ing to the regin of 3′ UTR of the target mRNAs. To date,it has been demonstrated for organism that miRNAs play an im-portant role in growth,development,and occurrence of disease. This paper introduces the character and the active mecha-nism of miRNAs,and the newest progress in the research on the function of microRNA,the identification of microRNA gene and the prediction of target gene also are summarized here.