Berlin 2018 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 27: Cell Mechanics II
BP 27.3: Vortrag
Donnerstag, 15. März 2018, 10:15–10:30, H 1028
Mechanical strain sensing in rod-shaped Escherichia coli — •Lars Renner1, Felix Wong2, Gizem Özbaykal3, Sven van Teeffelen3, and Ariel Amir2 — 1Leibniz Institute of Polymer Research Dresden — 2Harvard University, Cambridge, USA — 3Institut Pasteur, Paris, France
Why bacteria have evolved and maintained their specific shapes is a central question in bacterial cell biology. Bacteria are remarkably successful in achieving a precise shape and tightly coordinating cellular processes such as DNA replication, protein production and cell division, yet the underlying biophysical cues and the evolutionary advantage for one shape over another are largely unknown. We are setting out to understand how rod-shaped bacteria maintain their shape when subjected to mechanical deformation. In particular, we explore how mechanical force changes the bacteria morphology and consequently affects the bacterial shape after the mechanical force is released. We combine microfabrication tools and mathematical models to analyse cell shape recovery of E. coli with intentionally modified cell morphology under mechanical stress. When confined, cells are readily adapting to the new morphology. When released, bacterial cells recover their straight, rod-shaped morphologies. We find a straightening rate that is approximately twice the growth rate. By developing a theory of residual stresses, we identify mechanical stress-based nucleation of new growth sites to explain the enhanced straightening rate. Our results indicate a stress-based mechanism for shape regulation in rod-shape bacteria.