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Inner ear formation during the early larval development of Xenopus laevis
Author(s) -
Quick Quincy A.,
Serrano Elba E.
Publication year - 2005
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20610
Subject(s) - otic vesicle , biology , inner ear , anatomy , utricle , xenopus , saccule , vestibular system , membranous labyrinth , cochlea , lateral line , hair cell , zebrafish , neuroscience , in situ hybridization , biochemistry , gene expression , gene
The formation of the eight independent endorgan compartments (sacculus, utricle, horizontal canal, anterior canal, posterior canal, lagena, amphibian papilla, and basilar papilla) of the Xenopus laevis inner ear is illustrated as the otic vesicle develops into a complex labyrinthine structure. The morphology of transverse sections and whole‐mounts of the inner ear was assessed in seven developmental stages (28, 31, 37, 42, 45, 47, 50) using brightfield and laser scanning confocal microscopy. The presence of mechanosensory hair cells in the sensory epithelia was determined by identification of stereociliary bundles in cryosectioned tissue and whole‐mounts of the inner ear labeled with the fluorescent F‐actin probe Alexa‐488 phalloidin. Between stages 28 and 45, the otic vesicle grows in size, stereociliary bundles appear and increase in number, and the pars inferior and pars superior become visible. The initial formation of vestibular compartments with their nascent stereociliary bundles is seen by larval stage 47, and all eight vestibular and auditory compartments with their characteristic sensory fields are present by larval stage 50. Thus, in Xenopus , inner ear compartments are established between stages 45 and 50, a 2‐week period during which the ear quadruples in length in the anteroposterior dimension. The anatomical images presented here demonstrate the morphological changes that occur as the otic vesicle forms the auditory and vestibular endorgans of the inner ear. These images provide a resource for investigations of gene expression patterns in Xenopus during inner ear compartmentalization and morphogenesis. Developmental Dynamics 234:791–801, 2005. © 2005 Wiley‐Liss, Inc.