The deaf mouse mutant whirler suggests a role for whirlin in actin filament dynamics and stereocilia development
| Autor: | Mette M. Mogensen, Agnieszka K. Rzadzinska, Karen P. Steel |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
inner ear
hair cells cochlea macromolecular substances Biology Deafness Article Protein filament 03 medical and health sciences Mice 0302 clinical medicine Structural Biology medicine otorhinolaryngologic diseases Animals Cilia Cochlea stereocilia 030304 developmental biology 0303 health sciences Stereocilium whirlin Hair Cells Auditory Inner Mechanosensation Stereocilia Homozygote Membrane Proteins Proteins Cell Biology Actin cytoskeleton Mice Mutant Strains Cell biology Actin Cytoskeleton Hair Cells Auditory Outer medicine.anatomical_structure Organ of Corti Ear Inner actin filaments Mutation Microscopy Electron Scanning Intercellular Signaling Peptides and Proteins Hair cell sense organs organ of Corti 030217 neurology & neurosurgery |
| Zdroj: | Cell Motility and the Cytoskeleton |
| ISSN: | 1097-0169 0886-1544 |
| Popis: | Stereocilia, finger-like projections forming the hair bundle on the apical surface of sensory hair cells in the cochlea, are responsible for mechanosensation and ultimately the perception of sound. The actin cytoskeleton of the stereocilia contains hundreds of tightly cross-linked parallel actin filaments in a paracrystalline array and it is vital for their function. Although several genes have been identified and associated with stereocilia development, the molecular mechanisms responsible for stereocilia growth, maintenance and organisation of the hair bundle have not been fully resolved. Here we provide further characterisation of the stereocilia of the whirler mouse mutant. We found that a lack of whirlin protein in whirler mutants results in short stereocilia with larger diameters without a corresponding increase in the number of actin filaments in inner hair cells. However, a decrease in the actin filament packing density was evident in the whirler mutant. The electron-density at the tip of each stereocilium was markedly patchy and irregular in the whirler mutants compared with a uniform band in controls. The outer hair cell stereocilia of the whirler homozygote also showed an increase in diameter and variable heights within bundles. The number of outer hair cell stereocilia was significantly reduced and the centre-to-centre spacing between the stereocilia was greater than in the wildtype. Our findings suggest that whirlin plays an important role in actin filament packing and dynamics during postnatal stereocilium elongation. |
| Databáze: | OpenAIRE |
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