PINCH HITTING: When a walled Bacillus subtilis cell divides, complicated cellular machinery segregates its contents and builds a new peptidoglycan wall across its center (1) before the bacterium splits into two daughter cells (2). L-form bacteria, which don’t have cell walls, dispense with the normal replication methods, at least in some cases. Instead, L-forms produce extra cell membrane and extra chromosomes and become large and irregularly shaped (3). Biomechanical forces cause smaller cells to break off through blebbing (4) or tubulation (5).LUCY READING-IKKANDA
The paper
R. Mercier et al., “Excess membrane synthesis drives a primitive mode of cell proliferation,” Cell, 152:997-1007, 2013.
Bacterial cells usually divide in an orderly fashion, building new cell walls across their centers before they separate. But recent research suggests that cell division for bacterial L-forms, which lack a cell wall, is a haphazard affair—possibly more reminiscent of primitive cell replication than of modern-day bacterial reproduction.
Many bacterial species, ranging from the harmless soil bacterium Bacillus subtilis to the pathogenic Listeria monocytogenes, have L-forms. They are pared-down versions of ordinary cells of their species, containing nearly the same genes but lacking the exterior peptidoglycan coating that is a defining bacterial trait.
Jeff Errington, a cell and molecular biologist at Newcastle University in the U.K., ...
