Title: Cell motility and cell shape as a playground for physics

Abstract: Cells crawl and reorganize in the body to perform their functions, ranging from white blood cells finding bacteria to skin cells closing over a wound. These behaviors provide huge opportunities for physicists, not only because eukaryotic cells are actively-driven soft materials but also because cells must cope with a  noisy, fluctuating environment. I will discuss a few examples of how my group has explored these topics across scales from nanometers to millimeters. First, I will discuss how single septin molecules (tens of nm in size) can potentially discriminate between membranes with different curvatures at the micron scale – like an ant measuring the radius of a basketball. Second, I will talk about how interacting proteins can cooperate to sense the shape of a cell. Finally, I will show how cell shape can then play a role in a tissue of thousands of cells, where anisotropic cells become aligned in patterns akin to a nematic liquid crystal. Topological defects in this liquid crystalline order then can drive changes in cell behavior, like increases in density. These increases in density can occur if cell shape regulates cell division – and we present results from experimental collaborators suggesting division is driving these density increases.

Host: Mary Elting