PUBLICATION

A mutation in zebrafish affecting a localized cellular function required for normal ear development

Authors
Riley, B.B. and Grunwald, D.J.
ID
ZDB-PUB-961219-4
Date
1996
Source
Developmental Biology   179(2): 427-435 (Journal)
Registered Authors
Grunwald, David, Riley, Bruce
Keywords
none
MeSH Terms
  • Animals
  • Ear/embryology*
  • Gene Expression Regulation, Developmental*
  • Mutation
  • Zebrafish/embryology*
PubMed
8903357 Full text @ Dev. Biol.
Abstract
Zebrafish holds great potential as a model system for studying inner ear development because genetic techniques are highly efficient and inner ear development is a conspicuous and manipulable feature of zebrafish embryogenesis. Here we describe analysis of a semilethal dominant mutation, termed monolith (mnl), that specifically perturbs formation of the anterior (utricular) otolith in the developing ear. Other than the utricular otolith deficiency, all structures in the ear appear morphologically normal in mutant embryos, including posterior otoliths and all sensory epithelia. Expression patterns of several ear marker genes (msxC, msxD, and dlx3) also appear normal in the mutant. To identify the cell type(s) affected by the mnl mutation, chimeras were generated by transplanting dye-labeled +/+ cells into unlabeled mnl/mnl host embryos. Roughly half of such chimeras formed utricular otoliths normally, indicating that the transplanted wild-type cells rescued their mutant hosts. Detailed analysis of +/+ cell fates revealed that virtually all chimeras in which +/+ cells formed support cells in the utricular sensory epithelium were rescued. In contrast, wild-type cells forming other cell types (such as hair cells) or colonizing other regions of the host were not sufficient to facilitate rescue. These data indicate that support cells are required for normal otolith formation, providing the first experimentally established role for support cells in vertebrate sensory epithelia. The data also provide the first clear indication that otolith formation is controlled independently in different regions of the ear by localized cellular functions.
Genes / Markers
Figures
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Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes