CONICET | Buscador de Institutos y Recursos Humanos

An epithelial-like structure has been reported to participate in the formation of stalk tube, during multicellular development in the Amoebozoan Dictyostelium discoideum.This epithelial structure forms a collar and along its luminal space prestalk cells migrates to build up a stalk tube and concomitantly lift a mass of prespores. It constitutes at the same time an instance of epithelia morphogenesis coupled to cell differentiation and collective cell migration in a non-metazoan organism. Here we present preliminary analysis of the dynamics of this epithelial-like structure. On the one hand we have followed the collective cell migration of prestalk cells in the tip, identifying the areas where epithelial-to-mesenchymal transitions occur. We have also been able to detect apical-basal intercalations in the Dictyostelium epithelial-like structure; these apical-basal intercalations have been reported to be needed to accommodate tension and forces in curved epithelia in metazoan. Finally, we have started to assess the putative role of small GTPases in the regulation of this process. Preliminary results show that null mutants of racJ and racL are defective in spores elevation and tube formation suggesting a conserved role in the mechanisms of regulation of epithelial tubes morphogenesis.