Progenitor cells and regenerative potential in echinoderms : an in vivo and in vitro approach

Regenerative processes are very common in echinoderms. Regeneration takes place through the recruitment of progenitor cells (undifferentiated or differentiated) accumulating in the lesion region. The crucial point of the “progenitor” elements involved in regenerative processes, in terms of cell recruitment, sources and fate, and totipotentiality, pluripotentiality or unipotentiality, is a central problem, relevant for its topical interest. 1) Crinoids possess a spectacular regenerative potential utilized to replace the loss of internal and external organs. The process of arm regeneration in the feather star Antedon mediterranea, in particular, is the most extensively studied process. 2) The regular echinoid Paracentrotus lividus possess a large amount of coelomic fluid containing several cells, many of which contribute to repair (test regeneration) and are apparently quite similar to those already characterized in A. mediterranea. In order to characterize morphologically and functionally the phenotypes responsible for the regenerative processes mentioned above (1, 2), the present research is addressed to an extensive in vitro approach which represents the first attempt to culture the cells involved in echinoderm regeneration processes already described and partly characterized in vivo. We propose here an integrate and comparative analysis to identify the different cells and their involvement in processes such as migration, proliferation, differentiation and de-differentiation.