Blastema formation and skeletogenesis during arm regeneration of the brittle star Amphiura filiformis: cellular and molecular characterization. (360G-Wellcome-099745_Z_12_A)

The aim of this research project is to understand the initial stages of brittle star arm regeneration in terms of stem cell involvement, cell specification and the earliest activation of the skeletogenic gene regulatory network. The brittle star is a marine organism with a unique capability for regenerating whole arms post-amputation or after injury. To determine whether the regenerative blastema, a mass of proliferative cells giving rise to the entire structure, is composed of stem cells or dedifferentiating cells, molecular tools will be employed for their characterization. Stem cell markers and lineage tracing techniques will be used to identify the nature of the cells, their origins and migratory behaviour. The regenerating arm of the brittle star is contains several skeletal structures and the second aim of this project is to understand the cohort of signalling pathways involved in the early specification of the cell lineages which will develop into this adult tissue. This will be achieved by using molecular techniques and a candidate gene approach for studying the genes that have already been well-characterised in the closely-related sea urchin, , for which a complete gene regulatory network for the embryonic development of skeletogenic cells has been published.