The dynein regulatory complex is required for ciliary motility and otolith biogenesis in the inner ear.
In teleosts, proper balance and hearing depend on mechanical sensors in the inner ear. These sensors include actin-based microvilli and microtubule-based cilia that extend from the surface of sensory hair cells and attach to biomineralized 'ear stones' (or otoliths). Otolith number, size and placement are under strict developmental control, but the mechanisms that ensure otolith assembly atop specific cells of the sensory epithelium are unclear. Here we demonstrate that cilia motility is required for normal otolith assembly and localization. Using in vivo video microscopy, we show that motile tether cilia at opposite poles of the otic vesicle create fluid vortices that attract otolith precursor particles, thereby biasing an otherwise random distribution to direct localized otolith seeding on tether cilia. Independent knockdown of subunits for the dynein regulatory complex and outer-arm dynein disrupt cilia motility, leading to defective otolith biogenesis. These results demonstrate a requirement for the dynein regulatory complex in vertebrates and show that cilia-driven flow is a key epigenetic factor in controlling otolith biomineralization.
Colantonio
Jessica R
JR
Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA.
Vermot
Julien
J
Wu
David
D
Langenbacher
Adam D
AD
Fraser
Scott
S
Chen
Jau-Nian
JN
Hill
Kent L
KL
D000595:Amino Acid Sequence; D000818:Animals; D002923:Cilia / Q000378:metabolism / Q000502:physiology*; D004398:Dyneins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D044127:Epigenesis, Genetic; D006801:Humans; D018715:Microscopy, Video; D008868:Microtubule Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009068:Movement; D046912:Multiprotein Complexes / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D010037:Otolithic Membrane / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
D008868:Microtubule Proteins; D046912:Multiprotein Complexes; D029961:Zebrafish Proteins; C534631:gas8 protein, zebrafish; D004398:Dyneins