title: Crossregulation between En-2 and Wnt-1 in chick tectal development.
abstract: En-1, En-2 and Wnt-1 are proposed to be essential signals for the development of the optic tectum in chick embryos. Drosophila engrailed and wingless, homologs of En (En-1 and En-2) and Wnt-1, respectively, have been shown to crossregulate each other. In the present paper, it is reported that crossregulation between En-2 and Wnt-1 is preserved in the development of the chick optic tectum. When En-2 is overexpressed by the replication competent retroviral vector, Wnt-1 is expressed ectopically at the dorsal midline of the diencephalon. When Wnt-1 is introduced extrinsically either by ectopic transplantation of mesencephalon, or by implantation of Wnt-1 producing cells, En-2 is induced ectopically at the dorsal midline of the tel-diencephalic border. Thus, ectopic expression of En-2 and Wnt-1 leads to crossregulation of each other in the chick brain. As diencephalon transdifferentiates into the optic tectum by an appropriate signal, the crossregulation of En-2 and Wnt-1 in the diencephalon may mimic the relationship required for early development in the tectum.
authors.affiliation: Department of Molecular Neurobiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sugiyama
authors.forename: J
authors.initials: J
authors.lastname: Funahashi
authors.forename: J
authors.initials: J
authors.lastname: Kitajewski
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D016380:Brain Tissue Transplantation; D002478:Cells, Cultured / Q000637:transplantation; D002642:Chick Embryo; D003370:Coturnix / Q000196:embryology / Q000235:genetics; D004027:Diencephalon / Q000196:embryology; D047108:Embryonic Development; D005347:Fibroblasts / Q000637:transplantation; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008636:Mesencephalon / Q000637:transplantation; D051379:Mice; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D013047:Specific Pathogen-Free Organisms; D013477:Superior Colliculi / Q000196:embryology*; D014162:Transfection; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein
chemical_list: D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein; C495246:Wnt1 protein, mouse; C495245:Wnt1 protein, rat