Role of actomyosin network anisotropy in the generation of contractile forces during morphogenesis in C. elegans

Projet de stage : Using the techniques available in the lab, the master student will explore the role of the structural arrangement of the network on the generation of mechanical force using two approaches. First, the student will address this question during pulsed contraction, a dynamic process that drives actomyosin contractility during morphogenesis. We believe that structural anisotropy of the network plays a critical role in the ability of pulsed contractions to generate mechanical forces during embryonic development. Using single-molecule imaging, the student will track actin elongators of the formin family (CYK-1 ::GFP) as they polymerize the actin filaments to establish and quantify the structural anisotropy of the actin network. Then, to understand how the structural anisotropy of the actin meshwork favors contraction, the student will develop an optogenetic tool to recruit the formin CYK-1 locally. Proof of concept of the individual optogenetic components has already been performed in the lab. With the support of a technician, the student will create transgenic lines that bear an optogenetically controlled formin (CYK-1 ::GFP ::Cry-2), that can be recruited on demand at the cell surface. With this tool to modulate local actin assembly and structural anisotropy, the student will then address two essential questions : (1) how does structural anisotropy change the material properties of the actin, and (2) is structural anisotropy necessary/sufficient to promote local contraction of the network. The master student should have a solid background in cell biology, but should also feel comfortable working at the interface between cell biology, biochemistry and physics. Finally, he/she should have a strong drive to implement and use cutting-edge techniques blending these fields to make important contributions to cell and developmental biology.

Techniques mises en œuvre par le stagiaire : • Single-molecule Imaging • Image and data analysis (ImageJ, Matlab) • C. elegans genetics • Optogenetics