The lack of Emx2 causes impairment of Reelin signaling and defects of neuronal migration in the developing cerebral cortex.
Neocorticogenesis in mice homozygous for an Emx2 null allele is the topic of this article. The development of both main components of neocortex, primordial plexiform layer derivatives and cortical plate, was analyzed, paying special attention to radial migration of neurons forming the cortical plate. The products of the Reelin gene, normally playing a key role in orchestrating radial migration of these neurons, display normal distribution at the beginning of the cortical neuronogenesis but are absent in the neocortical marginal zone of the mutant mice at the time when the cortical plate is laid down. As a consequence, the development of radial glia is impaired, and neurons making up the cortical plate display abnormal migration patterns. In addition, restricted defects along the rostrocaudal and the mediolateral axes are present in the subplate, suggesting an Emx2-specific role in priming the proper development of this layer.
Mallamaci
A
A
Department of Biological and Technological Research (DIBIT), Istituto Scientifico H. San Raffaele, 20132 Milano, Italy. mallamaci.antonio@hsr.it
Mercurio
S
S
Muzio
L
L
Cecchi
C
C
Pardini
C L
CL
Gruss
P
P
Boncinelli
E
E
D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D002540:Cerebral Cortex / Q000196:embryology*; D004622:Embryo, Mammalian / Q000166:cytology; D005314:Embryonic and Fetal Development / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout / Q000235:genetics; D009154:Mutation / Q000502:physiology; D009419:Nerve Tissue Proteins; D009457:Neuroglia / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D000091042:Reelin Protein; D012697:Serine Endopeptidases; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors; D000099260:Empty Spiracles Homeobox Proteins
D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; D012697:Serine Endopeptidases; D014157:Transcription Factors; D000099260:Empty Spiracles Homeobox Proteins; C000717128:Reln protein, mouse