A-C: Division in C. crescentus imaged by cryoEM
tomography (reprinted from [37]). The shallow V shape was interpreted to indicate a
constrictive mode of division. A and B are slices through a 3D tomogram, while
(C) is a projection through the whole bacterium. D: Division of
E. coli imaged by cryoEM tomography, showing a slice
through the 3D tomogram (reprinted from [39]. The white arrow points to small dots identified as FtsZ
filaments in cross-section. This cell has a sharp, V-shaped constriction,
typical of constrictive division. The periplasm of this cell is considerably
expanded, especially at lower right. E: A dividing E.
coli cell prepared by high pressure freezing, freeze substitution
(reprinted from [40]. The
division shows a V-shaped constriction and a clearly extended invagination of
the IM, forming a septum.