Conversion of blebs to microvilli: cell surface reorganisation after trypsin.

The blebbed surface morphology produced by trypsinisation of Chinese hamster ovary cells is subsequently reorganized to a microvillous topography, even in the continued presence of trypsin. Scanning and transmission electron microscope (SEM and TEM) observations of this transition showed the initial formation of a "crown' of densely clustered microvilli at one pole of the cell. At the periphery of this region the blebs coalesced to form ridges which subsequently extended over the entire cell surface. Long, and occasionally branched microvilli were generated from the ridges. Large numbers of membrane associated vesicles were also characteristic of these areas of surface reorganisation.