But most scientists thought bacteria got their shapes from tough outer cell walls. In the latest issue of the journal Cell, researchers from Oxford, England, show that the rod-shaped Bacillus subtilis has a skeleton. A protein called MreB forms structures that run perpendicular to the long axis of the cell, apparently controlling cell width. A separate protein, Mbl, seems to maintain the germ's long, rod-like shape. The finding that bacteria can have internal skeletons may help doctors combat disease.
Many microbes change shape when they become infectious.
When splitting firewood, some logs come apart easily, with a single blow from a sharp ax. Others can be much more stubborn, requiring that a wedge or two be driven into the wood before it finally splits. Amoebas can be like firewood, too. Sometimes, however, the furrow stops developing and the reproductive process stops. Researchers at the Weizmann Institute of Science in Israel have discovered that in some cases, a struggling amoeba gets help.