Direct laser manipulation reveals the mechanics of cell contacts in vivo

Abstract

Significance: The shaping of tissues and organs relies on the ability of cells to adhere together and deform in a coordinated manner. It is, therefore, key to understand how cell-generated forces produce cell shape changes and how such forces transmit through a group of adhesive cells in vivo. In this context, we have developed an approach using laser manipulation to impose local forces on cell contacts in the early Drosophila embryo. Quantification of local and global shape changes using our approach can both provide direct measurements of the forces acting at cell contacts and delineate the time-dependent viscoelastic properties of the tissue. The latter provides an explicit relationship, the so-called constitutive law, between forces and deformations.