Meeting Abstract

22.1  Tuesday, Jan. 4  Cell proliferation is required for regeneration in the cnidarian Nematostella vectensis PASSAMANECK, Y.J.*; MARTINDALE, M.Q.; Kewalo Marine Laboratory, Univ. Hawaii; Kewalo Marine Laboratory, Univ. Hawaii yale@hawaii.edu

Within the Cnidaria, studies of growth and regeneration have traditionally focused on the derived medusozoan Hydra. By comparison, relatively little data has been collected on the details of polyp growth and regeneration in the basally divergent Anthozoa. To understand the basis of these processes in anthozoans, we have investigated the dynamics of cell proliferation in the emerging model Nematostella vectensis. By labelling S-phase cells with the thymidine analog EdU, we have found that during normal growth, cell proliferation occurs throughout the polyp, including in the tentacles. Following bisection of the polyp, elevated levels of cell proliferation are observed in the regenerating oral field. We tested the role of cell proliferation in regeneration by incubating bisected animals with either hydroxyurea, which inhibits DNA synthesis, or nocodazole, which arrests cells in mitosis. Treatment with either compound resulted in inhibition of regeneration of the tentacles and pharynx, demonstrating that cell proliferation is required for regrowth these structures in Nematostella. These results are in contrast to findings from Hydra, where regeneration of the tentacles can occur in the absence of cell proliferation. Our results highlight the diversity of regenerative mechanisms within the Cnidaria, and the value of Nematostella as a model for outgroup comparisons with studies of regeneration in bilaterians.