Length regulation of mechanosensitive stereocilia depends on very slow actin dynamics and filament-severing proteins

Auditory sensory hair cells detect sounds by deflection of their actin-based stereocilia, which vary in length. By inducing expression of GFP-actin in mouse hair cells in vivo, Narayanan et al. demonstrate that stereocilia length is regulated by very slow actin turnover, which is restricted to the tips.