Neuronal expression of regulatory helix-loop-helix factor Id2 gene in mouse.
Id-like helix-loop-helix (HLH) proteins, which lack a basic DNA binding domain, have been suggested to serve as general inhibitors of differentiation. We present data that Id2 is expressed in specific cell types during neurogenesis and in the adult. At early stages of neurogenesis, Id2 is expressed in the ventricular zone of neuroepithelium. After the first neuronal populations are born, the expression of Id2 is down regulated in neuroepithelial cells and continues to be high in Purkinje cells of the cerebellum, in mitral cells of the olfactory bulb, and in layers 2, 3, and 5 of the cerebral cortex. In neuronally differentiating cell lines, the Id2 expression is up regulated (PCC7), down regulated (NG108), or unchanged (N18) during differentiation. Analyses of promoter sequences of the Id2 gene identify the region which is responsible for the down regulation of transcription during neuronal differentiation. Our data indicate that Id2 has different functions in different cell types during neurogenesis.
Neuman
T
T
Department of Anatomy and Neurobiology, Colorado State University, Fort Collins 80523.
Keen
A
A
Zuber
M X
MX
Kristjansson
G I
GI
Gruss
P
P
Nornes
H O
HO
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000196:embryology / Q000254:growth & development; D002454:Cell Differentiation; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D015536:Down-Regulation; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D017403:In Situ Hybridization; D051798:Inhibitor of Differentiation Protein 1; D051379:Mice; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009928:Organ Specificity / Q000235:genetics; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins; D015183:Restriction Mapping; D014157:Transcription Factors
D017931:DNA Primers; D004268:DNA-Binding Proteins; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D014157:Transcription Factors