Abstract

During early development and wound healing, epithelial cells (cohesive cells) that form a monolayer sheet sometimes move collectively in a definite direction in the sheet; that is, the cohesive cells move unidirectionally while maintaining the attachments with adjacent cells. This phenomenon is called collective migration of epithelial cells [1], and is considered to be an essential factor for morphological changes of multicellular organisms [2]. While the molecular mechanisms underlying this phenomenon are becoming understood, much of the mechanical mechanisms remain still unclear. In the present talk, I will provide one possible mechanism for collective migration from a theoretical point of view [3]: If the cell boundaries contract depending on their orientation (planar polarity), and spatial inhomogeneity about the cell properties, such as strength of cell adhesion, exists, then the cohesive cells collectively move in the direction perpendicular to that of spatial inhomogeneity, by repeating rearrangement of neighbor relationships. I will demonstrate this scenario by using the vertex model, and reproduce the behaviors of typical collective cell migration such as that seen in zebrafish lateral line primordium. I also provide experimental evidence for this type of movement by investigating a phenomenon in development of fly, where monolayer epithelial sheets move 360 degrees clockwise around the genital disc [4].

Refs: 1. P. Friedl and D. Gilmour, (2009) Nat. Rev. Mol. Cell Biol. 10, 445-457. 2. J. Davies, Mechanisms of Morphogenesis (Academic Press, Second Edition, 2013). 3. K. Sato, T. Hiraiwa, and T. Shibata, Phys. Rev. Lett. 115, 188102 (2015). 4. K. Sato, T. Hiraiwa, E. Maekawa, A. Isomura, T. Shibata, and E. Kuranaga, Nat. Commun. 6, 10074 (2015).