ZFIN ID: ZDB-PUB-121205-2
Cell lineage analysis reveals three different progenitor pools for neurosensory elements in the otic vesicle
Sapède, D., Dyballa, S., and Pujades, C.
Date: 2012
Source: The Journal of neuroscience : the official journal of the Society for Neuroscience   32(46): 16424-16434 (Journal)
Registered Authors: Pujades, Cristina
Keywords: none
MeSH Terms:
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors/genetics
  • Blotting, Western
  • Cell Count
  • Cell Lineage/physiology*
  • Ear, Inner/physiology*
  • Epithelium/physiology
  • Gene Expression Regulation/drug effects
  • Hair Cells, Auditory/physiology
  • Image Processing, Computer-Assisted
  • In Situ Hybridization
  • Nerve Tissue Proteins/genetics
  • Neural Stem Cells/physiology*
  • Oligonucleotides, Antisense/pharmacology
  • Sensory Receptor Cells/physiology*
  • Stem Cells/physiology
  • Zebrafish/physiology*
  • Zebrafish Proteins/genetics
PubMed: 23152625 Full text @ J. Neurosci.

In the inner ear, sensory versus neuronal specification is achieved through few well-defined bHLH transcription factors. However, the molecular mechanisms regulating the generation of the appropriate cell type in the correct place and at the correct time are not completely understood yet. Various studies have shown that hair cell- and neuron-specifying genes partially overlap in the otic territory, suggesting that mutual interactions among these bHLH factors could direct the generation of the two cell types from a common neurosensory progenitor. Although there is little evidence for a clonal relationship between macular hair cells and sensory neurons, the existence of a single progenitor able to give both sensory and neuronal cell types remains an open question. Here, we identified a population of common neurosensory progenitors in the zebrafish inner ear and studied the proneural requirement for cell fate decision within this population. Expression analysis reveals that proneural genes for hair cells and neurons overlap within the posteromedial otic epithelium. Combined results from single-cell lineage and functional studies on neurog1 and neuroD1 further demonstrate the following: (1) in the anterior region of the ear, neuronal and sensory lineages have already segregated at the onset of proneural gene expression and are committed to a given fate very early; (2) in contrast, the posteromedial part of the ear harbors a population of common progenitors giving both neurons and hair cells until late stages; and finally (3) neuroD1 is required within this pool of bipotent progenitors to generate the hair cell fate.