Pax6 regulates regional development and neuronal migration in the cerebral cortex.
Mutations in the Pax6 gene disrupt telencephalic development, resulting in a thin cortical plate, expansion of proliferative layers, and the absence of the olfactory bulb. The primary defect in the neuronal cell population of the developing cerebral cortex was analysed by using mouse chimeras containing a mixture of wild-type and Pax6-deficient cells. The chimeric analysis shows that Pax6 influences cellular activity throughout corticogenesis. At early stages, Pax6-deficient and wildtype cells segregate into exclusive patches, indicating an inability of different cell genotypes to interact. At later stages, cells are sorted further based on telencephalic domains. Pax6-deficient cells are specifically reduced in the mediocaudal domain of the dorsal telencephalon, indicating a role in regionalization. In addition, Pax6 regulates the process of radial migration of neuronal precursors. Loss of Pax6 particularly affects movement of neuronal precursors at the subventricular zone/intermediate zone boundary at a transitional migratory phase essential for entry into the intermediate zone. We suggest that the primary role of Pax6 is the continual regulation of cell surface properties responsible for both cellular identity and radial migration, defects of which cause regional cell sorting and abnormalities of migration in chimeras.
Talamillo
Ana
A
Comparative and Developmental Genetics Section, MRC Human Genetic Unit, Western General Hospital, Edinburgh, UK.
Quinn
Jane C
JC
Collinson
J Martin
JM
Caric
Damira
D
Price
David J
DJ
West
John D
JD
Hill
Robert E
RE
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D002540:Cerebral Cortex / Q000737:chemistry / Q000166:cytology / Q000196:embryology*; D002678:Chimera; D003433:Crosses, Genetic; D005136:Eye Proteins; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D006720:Homozygote; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D009154:Mutation; D009474:Neurons / Q000166:cytology / Q000502:physiology; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D011247:Pregnancy; D016548:Prosencephalon / Q000166:cytology / Q000196:embryology; D012097:Repressor Proteins; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D019076:Transgenes
D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D014157:Transcription Factors