Mapping spatio-temporal activation of Notch signaling during neurogenesis and gliogenesis in the developing mouse brain.
Notch1 plays various important roles including the maintenance of the stem cell state as well as the promotion of glial fates in mammalian CNS development. However, because of the very low amount of the activated form of Notch1 present in vivo, its precise activation pattern has remained unknown. In this study, we mapped the active state of this signaling pathway in situ in the developing mouse brain using a specific antibody that recognizes the processed form of the intracellular domain of Notch1 cleaved by presenilin/gamma-secretase activity. By using this antibody, active state of Notch1 came to be detectable with a higher sensitivity than using conventional antibody against Notch1. We found that activated Notch1 was mainly detected in the nuclei of a subpopulation of radial glial cells, the majority of proliferating precursor cells in the ventricular zone (VZ). However, Notch1 activation was not detected in neuronal precursor cells positive for neuronal basic helix-loop-helix proteins or in differentiating neurons in the embryonic forebrain. Interestingly, we found that Notch1 was transiently activated in the astrocytic lineage during perinatal CNS development. Taken together, the present method has enabled us to determine the timing, gradients, and boundaries of the activation of Notch signaling.
Tokunaga
Akinori
A
Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
Kohyama
Jun
J
Yoshida
Tetsu
T
Nakao
Keiko
K
Sawamoto
Kazunobu
K
Okano
Hideyuki
H
D000818:Animals; D000831:Animals, Newborn; D000918:Antibody Specificity; D051792:Basic Helix-Loop-Helix Proteins; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D041681:NIH 3T3 Cells; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface; D014157:Transcription Factors; C499317:Ascl1 protein, mouse; C491183:NEUROG2 protein, human; C102938:Neurog2 protein, mouse; C497762:Notch1 protein, mouse