Establishment of framework of the cortical area is influenced by Otx1.
Subcortical projection from layer 5 neurons is the major cortical output. A transcription factor, Otx1, which is expressed in the layer 5 subcortical projection neurons in the visual cortex, was reported to be responsible for the establishment of visual area-specific layer 5 subcortical projections by inducing the sensorimotor cortex to adopt a visual cortex identity. However, we here demonstrate that the area of corticospinal neurons shifted caudo-medially in the Otx1-null mice of which cortex is 9 tenths in size compared with that of the wild-type littermates, while the whole visual cortex did not convert to the sensorimotor cortex in the absence of Otx1. This suggests that Otx1 is not crucial for the development of visual cortex identity but for the determination of the proportion of cortical areas to the whole neocortex.
Ando
Koichi
K
Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, University of Fukui, Fukui 910-1193, Japan.
Yagi
Hideshi
H
Suda
Yoko
Y
Aizawa
Shinichi
S
Sakashita
Masanori
M
Nagano
Takashi
T
Terashima
Toshio
T
Sato
Makoto
M
D000578:Amidines / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001931:Brain Mapping; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D051797:Inhibitor of Differentiation Protein 2 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009434:Neural Pathways / Q000254:growth & development / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D051857:Otx Transcription Factors / Q000172:deficiency / Q000502:physiology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000254:growth & development; D014793:Visual Cortex / Q000166:cytology* / Q000502:physiology*
D000578:Amidines; D015820:Cadherins; C504541:Cdh8 protein, mouse; C497452:Idb2 protein, mouse; D051797:Inhibitor of Differentiation Protein 2; D051857:Otx Transcription Factors; C497656:Otx1 protein, mouse; C031455:diamidino compound 253-50