The role of nerve in regeneration in Aeolosoma viride ‐a new model for regeneration

Abstract

Several kinds of animal models, such as planarian, hydra, and salamander have been studied on regeneration, which is the way of animals to repair their lost tissues. Compared with highly differentiated and much complicated salamander, the body plan of planarian and hydra with no coelom and body segmentation is much simpler than that of salamander. There is a large evolutionary gap among them. Based on the well-accepted phylogenic relationship, annelids with true coelom and body segmentation have the evolutional position between them. Aeolosoma viride, an annelid living in fresh water possesses great regeneration ability: four days to regenerate its head and three days to regenerate its tail. Their cell proliferation and blastema formation near the wounded site could be observed by BrdU staining. In salamander, the blastema can¡¦t form and regeneration fails in its legs after the wounded nerve is destroyed. In planarian, the body axial was lost after the nerve was removed. In our study, an A. viride treated with AG879, the inhibitor of the nerve growth factor receptor, its regeneration was obviously delayed, but still alive. This resul suggested that nerves also govern regeneration in A. viride. In addition, A. viride reproduces asexually and is easily maintained in lab, we believe it can be a new animal model for further regeneration study.