MicroRNAs in planarian regeneration (LB14)

Abstract

Planarian, with the robust regeneration ability, has been used as a model organism for stem cell research in recent years. Regeneration in planarian is mediated by adult stem cells, called neoblasts, which can proliferate and differentiate into almost all cell types for replacing the whole body. MicroRNAs are 20‐24nt small non‐coding RNAs that are associated with Argonaut proteins and form miRNA‐induced silencing complex (miRISC) to regulate gene expression at post‐transcriptional level. Our preliminary study showed that a certain population of miRNAs are highly expressed in regenerating tissues, implicates the potential important roles of miRNAs in neoblasts during regeneration. Interestingly, depeletion of planarian Argonaute 2 (DjAgo2) results in a dramatic effect of head degeneration, suggesting that miRNAs are also required for planarian homeostasis. In this study, we further examined the roles of specific miRNAs in planarian. We developed a method to specifically block the function of miRNA. Successful inhibition of several candidate miRNAs results in a degeneration phenotype in planarian treated with miRNA inhibitors. This result proved our hypothesis that miRNAs indeed participate in self‐renewal of stem cells and the differentiation process in planarian.