Editor's Summary
12 February 2009
Life without walls
Bacteria depend on a cell wall for protection against physical and chemical damage and osmotic lysis. But rare L-form cells, thought to lack a cell wall, have been observed in some bacterial species. They may play a role in avoiding recognition by host immune systems and antibiotics such as the penicillins that target cell wall synthesis. But L-form cells are extremely difficult to grow and manipulate, hence difficult to study. This could change with the development of a route to genetically tractable L-form cells of the common model organism, Bacillus subtilis. Early findings with this new system are the confirmation that no cell wall synthesis is needed for L-form cells to replicate, and that the normal cell division machinery is not required. Instead, L-forms use an extrusion-resolution mechanism to proliferate, forming multiple progeny in a single step. These findings could have evolutionary implications. The cell wall is found throughout the bacterial sub-kingdom, so was probably present in the last common ancestor of these ancient organisms. The novel replication process used by L-form cells could provide a window into modes of proliferation used before the advent of the cell wall.
Authors: Abstractions
doi:10.1038/7231762b
Article: Life without a wall or division machine in Bacillus subtilis
M. Leaver, P. Domínguez-Cuevas, J. M. Coxhead, R. A. Daniel & J. Errington
doi:10.1038/nature07742
Abstract | Full Text | PDF (647K) | Supplementary information
