Sonic hedgehog: a common signal for ventral patterning along the rostrocaudal axis of the neural tube.
The vertebrate hedgehog-related gene, sonic hedgehog, is expressed in ventral domains along the entire rostrocaudal length of the neural tube, including the forebrain. Shh induces the differentiation of ventral neuronal cell types in explants derived from prospective forebrain regions of the neural plate. Neurons induced in explants derived from diencephalic and telencephalic levels of the neural plate express the LIM homeodomain protein Islet-1, but these neurons possess distinct identities that match those of the ventral neurons normally generated in these two subdivisions of the forebrain. These results, together with other studies of neuronal differentiation at caudal levels of the neural tube, suggest that a single inducing molecule, Shh, mediates the induction of distinct ventral neuronal cell types along the entire rostrocaudal extent of the embryonic central nervous system.
Ericson
J
J
Department of Microbiology, University of Umeä, Sweden.
Muhr
J
J
Jessell
T M
TM
Edlund
T
T
D000818:Animals; D002454:Cell Differentiation; D002490:Central Nervous System / Q000196:embryology*; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004027:Diencephalon / Q000196:embryology; D004330:Drosophila; D004627:Embryonic Induction; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins / Q000096:biosynthesis; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009420:Nervous System / Q000166:cytology / Q000196:embryology*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D016548:Prosencephalon / Q000196:embryology*; D014176:Protein Biosynthesis; D013687:Telencephalon / Q000196:embryology; D015534:Trans-Activators; D014157:Transcription Factors; D014714:Vertebrates
D004268:DNA-Binding Proteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1