The RhoA signaling pathway is required for planarian intestinal regeneration

Although some animals are capable of regenerating organs, the mechanisms by which this is achieved are poorly understood. For most tissues and organs, the spatiotemporal dynamics of stem cell differentiation and the fate of tissue that existed prior to injury have not been characterized systematically. Planarians are able to regenerate any missing part of their body after injury, and are thus ideally suited for investigating organ regeneration. Here, we show that Rap1/RhoA/Cofilin pathway is responsible for the intestinal and neural regeneration in planarians. We found that Rap1 is enriched in planarian eyes and intestinal tissues. Both Rap1(RNAi) and RhoA(RNAi) animal commence with decreased expression of gut-specific progenitor marker. Meanwhile, knockdown of Cofilin, which co-expressed with RhoA, caused similar phenotypes with RhoA(RNAi). Moreover, we identified Rnd as a negative regulator of RhoA, the silencing of which recover the defects observed in RhoA(RNAi) animals. Therefore, our findings indicate that Rap1/RhoA/Cofilin pathway is an important regulator of the intestinal regeneration.