title: Periventricular notch activation and asymmetric Ngn2 and Tbr2 expression in pair-generated neocortical daughter cells.
abstract: To understand the cellular and molecular mechanisms regulating cytogenesis within the neocortical ventricular zone, we examined at high resolution the spatiotemporal expression patterns of Ngn2 and Tbr2. Individually DiI-labeled daughter cells were tracked from their birth in slice cultures and immunostained for Ngn2 and Tbr2. Both proteins were initially absent from daughter cells during the first 2 h. Ngn2 expression was then initiated asymmetrically in one of the daughter cells, with a bias towards the apical cell, followed by a similar pattern of expression for Tbr2, which we found to be a direct target of Ngn2. How this asymmetric Ngn2 expression is achieved is unclear, but gamma-secretase inhibition at the birth of daughter cells resulted in premature Ngn2 expression, suggesting that Notch signaling in nascent daughter cells suppresses a Ngn2-Tbr2 cascade. Many of the nascent cells exhibited pin-like morphology with a short ventricular process, suggesting periventricular presentation of Notch ligands to these cells.
authors.affiliation: Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi 466-8550, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Ochiai
authors.forename: Sayaka
authors.initials: S
authors.lastname: Nakatani
authors.forename: Taishi
authors.initials: T
authors.lastname: Takahara
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kainuma
authors.forename: Makoto
authors.initials: M
authors.lastname: Masaoka
authors.forename: Sayaka
authors.initials: S
authors.lastname: Minobe
authors.forename: Masakazu
authors.initials: M
authors.lastname: Namihira
authors.forename: Kinichi
authors.initials: K
authors.lastname: Nakashima
authors.forename: Akira
authors.initials: A
authors.lastname: Sakakibara
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ogawa
authors.forename: Takaki
authors.initials: T
authors.lastname: Miyata
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D001570:Benzodiazepinones / Q000494:pharmacology; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D019579:Neocortex / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis / Q000502:physiology*; D011401:Promoter Regions, Genetic; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D001570:Benzodiazepinones; D050760:Cyclin-Dependent Kinase Inhibitor p27; D009419:Nerve Tissue Proteins; D051880:Receptors, Notch; D020825:T-Box Domain Proteins; C529132:2-(((3,5-difluorophenyl)acetyl)amino)-N-(1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-3-yl)propanamide; C491198:Eomes protein, mouse; C102938:Neurog2 protein, mouse