title: Role of En2 in the tectal laminar formation of chick embryos.
abstract: The chick optic tectum consists of 16 laminae. Here, we report contribution of En2 to laminar formation in chick optic tecta. En2 is specifically expressed in laminae g-j of stratum griseum et fibrosum superficiale (SGFS). Misexpression of En2 resulted in disappearance of En2-expressing cells from the superficial layers (laminae a-f of SGFS), where endogenous En2 is not expressed. Misexpression of En2 before postmitotic cells had left the ventricular layer indicated that En2-misexpressing cells stopped at the laminae of endogenous En2 expression and that they did not migrate into the superficial layers. Induction of En2 misexpression using a tetracycline-inducible system after the postmitotic cells had reached superficial layers also resulted in disappearance of En2-expressing cells from the superficial layers. Time-lapse analysis showed that En2-misexpressing cells migrated back from the superficial layers towards the middle layers, where En2 is strongly expressed endogenously. Our results suggest a potential role of En2 in regulating cell migration and positioning in the tectal laminar formation.
authors.affiliation: Department of Molecular Neurobiology, Graduate School of Life Sciences, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Omi
authors.forename: Hidekiyo
authors.initials: H
authors.lastname: Harada
authors.forename: Yuji
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Funahashi
authors.forename: Harukazu
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002465:Cell Movement / Q000235:genetics; D002642:Chick Embryo; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000502:physiology*; D009024:Morphogenesis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D009899:Optic Lobe, Nonmammalian / Q000196:embryology* / Q000378:metabolism; D012160:Retina / Q000196:embryology / Q000378:metabolism; D003336:Tectum Mesencephali / Q000196:embryology* / Q000378:metabolism; D000099266:Engrailed 2 Protein
chemical_list: D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000099266:Engrailed 2 Protein
keywords: Chick; Engrailed-2; Laminar formation; Optic tectum