Abstract
The mechanosensitive hair bundles of vertebrate hair cells exhibit a remarkable variety of shapes. For a given location in a sensory epithelium, however, the shape and polarity of a hair bundle are specified precisely. Recent findings, in particular with analogous experimental systems of actin polymerization, suggest a model of hair-bundle morphogenesis whereby different Rho guanosine triphosphatases (GTPases) regulate the initiation phase and the elongation phase of local actin-filament assembly at the hair cell's apical membrane.
