α-Catenin Mediates the Emergence of an Elastic Restoring Force Driving Pulsatile Apical Contraction

Autor: Jurado-Gómez, Jaime, Navascués, Joaquín de, Gorfinkiel, Nicole
Přispěvatelé: Ministerio de Ciencia e Innovación (España), European Commission
Rok vydání: 2014
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Póster presentado en el X Meeting Spanish Society for Developmental Biology, celebrado en Madrid del 13 al 15 de octubre de 2014.
Apical contraction is a common cell shape change that drives different morphogenetic processes in the context of embryonic development. During Dorsal Closure (DC) in Drosophila, amnioserosa (AS) cells apically contract and generate one of the major forces to close a discon6nuity in the dorsal region of the embryo. Apical contraction in these cells is pulsatile and driven by the oscillating activity of the medial actomyosin cytoskeleton. The frequency and amplitude of apical cell area fluctuations evolves in a stereotyped manner during DC as apical cell area reduces. Theoretical models of actomyosin and cell area oscillations predict the existence of an elastic restoring force whose stiffness modulates the frequency of oscillations. In this context, we have analysed the function of α-Catenin as a physical linker between the actin cytoskeleton and the apical membrane. Using genetics, quantitative live imaging and mechanical perturbation, we have analysed an α-Catenin allelic series in which the C-terminal/actin-binding region of the protein has been progressively eliminated. All the alleles tested are embryonic lethal and develop head and dorsal-open phenotypes in cuticle preparations. The quantitative analysis of the dynamics of DC shows that in these embryos the overall rate of DC is slower, and importantly, this is accompanied by a decrease in the frequency of oscillations. Cell and tissue tension does not develop as inferred from the corrugated appearance of the membranes. Finally, there is a delay in the onset of net contraction. Altogether, our results suggest that the binding of α-Catenin to the actin cytoskeleton provides a molecular basis for an elastic restoring force modulating the frequency of cell area oscillations and mediating the emergence of tissue tension.
We thank the following funding bodies for their support: Ministerio de Ciencia e Innovación (NG, BFU2011-25828 and “Ramón y Cajal” fellowship award), Marie Curie Career Integration Grant (NG, PCIG09-GA-2011- 293479).
Databáze: OpenAIRE