The bHLH protein NEUROGENIN 2 is a determination factor for epibranchial placode-derived sensory neurons.
neurogenin2 encodes a neural-specific basic helix-loop-helix (bHLH) transcription factor related to the Drosophila proneural factor atonal. We show here that the murine ngn2 gene is essential for development of the epibranchial placode-derived cranial sensory ganglia. An ngn2 null mutation blocks the delamination of neuronal precursors from the placodes, the first morphological sign of differentiation in these lineages. Mutant placodal cells fail to express downstream bHLH differentiation factors and the Notch ligand Delta-like 1. These data suggest that ngn2 functions like the Drosophila proneural genes in the determination of neuronal fate in distal cranial ganglia. Interestingly, the homeobox gene Phox2a is activated independently of ngn2 in epibranchial placodes, suggesting that neuronal fate and neuronal subtype identity may be specified independently in cranial sensory ganglia.
Fode
C
C
IGBMC, CNRS/INSERM/Université Louis Pasteur, Illkirch, C. U. de Strasbourg, France.
Gradwohl
G
G
Morin
X
X
Dierich
A
A
LeMeur
M
M
Goridis
C
C
Guillemot
F
F
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000235:genetics; D003391:Cranial Nerves / Q000002:abnormalities / Q000166:cytology / Q000196:embryology; D005260:Female; D017950:Ganglia, Sensory / Q000002:abnormalities / Q000166:cytology / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D018257:Helix-Loop-Helix Motifs / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology; D016296:Mutagenesis / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D009475:Neurons, Afferent / Q000737:chemistry / Q000502:physiology*; D011247:Pregnancy; D019170:Somites / Q000166:cytology; D013234:Stem Cells / Q000737:chemistry / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; C102938:Neurog2 protein, mouse; C491060:Phox2a protein, mouse