Pyramidal neurons of upper cortical layers generated by NEX-positive progenitor cells in the subventricular zone.
The generation of pyramidal neurons in the mammalian neocortex has been attributed to proliferating progenitor cells within the ventricular zone (VZ). Recently, the subventricular zone (SVZ) has been recognized as a possible source of migratory neurons in brain slice preparations, but the relevance of these observations for the developing neocortex in vivo remains to be defined. Here, we demonstrate that a subset of progenitor cells within the SVZ of the mouse neocortex can be molecularly defined by Cre recombinase expression under control of the NEX/Math2 locus, a neuronal basic helix-loop-helix gene that by itself is dispensable for cortical development. NEX-positive progenitors are generated by VZ cells, move into the SVZ, and undergo multiple asymmetrical and symmetrical cell divisions that produce a fraction of the neurons in the upper cortical layers. Our data suggest that NEX-positive progenitors within the SVZ are committed to a glutamatergic neuronal fate and have evolved to expand the number of cortical output neurons that is characteristic for the mammalian forebrain.
Wu
Sheng-Xi
SX
Department of Morphological Brain Science and Laboratory of Immunological Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Goebbels
Sandra
S
Nakamura
Kouichi
K
Nakamura
Kazuhiro
K
Kometani
Kouhei
K
Minato
Nagahiro
N
Kaneko
Takeshi
T
Nave
Klaus-Armin
KA
Tamamaki
Nobuaki
N
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis* / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology; D002478:Cells, Cultured; D002552:Cerebral Ventricles / Q000166:cytology*; D017930:Genes, Reporter; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019579:Neocortex / Q000166:cytology / Q000196:embryology*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000502:physiology; D017966:Pyramidal Cells / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology
D051792:Basic Helix-Loop-Helix Proteins; D009419:Nerve Tissue Proteins; C110701:Neurod6 protein, mouse