title: Cyclopia and defective axial patterning in mice lacking Sonic hedgehog gene function.
abstract: Targeted gene disruption in the mouse shows that the Sonic hedgehog (Shh) gene plays a critical role in patterning of vertebrate embryonic tissues, including the brain and spinal cord, the axial skeleton and the limbs. Early defects are observed in the establishment or maintenance of midline structures, such as the notochord and the floorplate, and later defects include absence of distal limb structures, cyclopia, absence of ventral cell types within the neural tube, and absence of the spinal column and most of the ribs. Defects in all tissues extend beyond the normal sites of Shh transcription, confirming the proposed role of Shh proteins as an extracellular signal required for the tissue-organizing properties of several vertebrate patterning centres.
authors.affiliation: Laboratory of Mammalian Genes and Development, National Institute of Health, Bethesda, Maryland 20892, USA. chiangc@dir6.nichd.nih.gov
authors.forename: C
authors.initials: C
authors.lastname: Chiang
authors.forename: Y
authors.initials: Y
authors.lastname: Litingtung
authors.forename: E
authors.initials: E
authors.lastname: Lee
authors.forename: K E
authors.initials: KE
authors.lastname: Young
authors.forename: J L
authors.initials: JL
authors.lastname: Corden
authors.forename: H
authors.initials: H
authors.lastname: Westphal
authors.forename: P A
authors.initials: PA
authors.lastname: Beachy
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D001921:Brain / Q000196:embryology; D002460:Cell Line; D005123:Eye / Q000196:embryology; D005333:Fetus / Q000002:abnormalities / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting; D053823:Hedgehog Proteins; D008648:Mesoderm; D051379:Mice; D009436:Neural Tube Defects / Q000235:genetics; D009672:Notochord / Q000002:abnormalities / Q000196:embryology; D009915:Orbit / Q000002:abnormalities / Q000196:embryology; D016548:Prosencephalon / Q000002:abnormalities / Q000196:embryology; D011506:Proteins / Q000235:genetics* / Q000502:physiology; D015534:Trans-Activators
chemical_list: D053823:Hedgehog Proteins; D011506:Proteins; D015534:Trans-Activators