Asymmetric chromosome segregation and cell division in DNA damage-induced bacterial filaments

Abstract

Faithful propagation of life requires coordination of DNA replication and segregation with cell growth and division. In bacteria, this results in cell size homeostasis and periodicity in replication and division. The situation is perturbed under stress such as DNA damage, which induces filamentation as cell cycle progression is blocked to allow for repair. Mechanisms that release this morphological state for re-entry into wild type growth are unclear. Here we show that damage recovery is mediated via asymmetric division of Escherichia coli filaments, producing short daughter cells with wild type size and growth dynamics. Division restoration at this polar site is governed by coordinated action of divisome positioning by the Min system and modulation of division licensing by the terminus region of the chromosome, with MatP playing a central role in this process. Collectively, our study highlights a key role for concurrency between chromosome (and specifically terminus) segregation and cell division in daughter cell size maintenance during filamentous divisions and suggests a central function for asymmetric division in mediating cellular recovery from a stressed state.