Staggered cell-intrinsic timing of ath5 expression underlies the wave of ganglion cell neurogenesis in the zebrafish retina. Development 2005 Jun;132(11):2573-85
Date
04/29/2005Pubmed ID
15857917DOI
10.1242/dev.01831Scopus ID
2-s2.0-21244503529 (requires institutional sign-in at Scopus site) 101 CitationsAbstract
In the developing nervous system, progenitor cells must decide when to withdraw from the cell cycle and commence differentiation. There is considerable debate whether cell-extrinsic or cell-intrinsic factors are most important for triggering this switch. In the vertebrate retina, initiation of neurogenesis has recently been explained by a 'sequential-induction' model--signals from newly differentiated neurons are thought to trigger neurogenesis in adjacent progenitors, creating a wave of neurogenesis that spreads across the retina in a stereotypical manner. We show here, however, that the wave of neurogenesis in the zebrafish retina can emerge through the independent action of progenitor cells--progenitors in different parts of the retina appear pre-specified to initiate neurogenesis at different times. We provide evidence that midline Sonic hedgehog signals, acting before the onset of neurogenesis, are part of the mechanism that sets the neurogenic timer in these cells. Our results highlight the importance of intrinsic factors for triggering neurogenesis, but they also suggest that early signals can modulate these intrinsic factors to influence the timing of neurogenesis many cell cycles later, thereby potentially coordinating axial patterning with control of neuron number and cell fate.
Author List
Kay JN, Link BA, Baier HAuthor
Brian A. Link PhD Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCell Differentiation
Chimera
DNA Primers
DNA-Binding Proteins
Ganglia, Sensory
Gene Expression Regulation, Developmental
Growth Substances
Hedgehog Proteins
Lasers
Micromanipulation
Retinal Ganglion Cells
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Stem Cells
Time Factors
Trans-Activators
Veratrum Alkaloids
Zebrafish
Zebrafish Proteins