title: Retinal determination genes as targets and possible effectors of extracellular signals.
abstract: Retinal determination genes are sufficient to specify eyes in ectopic locations, raising the question of how these master regulatory genes define an eye developmental field. Genetic mosaic studies establish that expression of the retinal determination genes eyeless, teashirt, homothorax, eyes absent, sine oculis, and dachshund are each regulated by combinations of Dpp, Hh, N, Wg, and Ras signals in Drosophila. Dpp and Hh control eyeless, teashirt, sine oculis, and dachshund expression, Dpp and Ras control homothorax, and all the signaling pathways affect eyes absent expression. These results suggest that eye-specific development uses retinal determination gene expression to relay positional information to eye target genes, because the distinct, overlapping patterns of retinal determination gene expression reflect the activities of the extracellular signaling pathways.
authors.affiliation: Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. lucy.firth@syngenta.com
authors.forename: Lucy C
authors.initials: LC
authors.lastname: Firth
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Baker
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D051155:Wnt1 Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C087345:So protein, Drosophila; D051155:Wnt1 Protein; C103968:dac protein, Drosophila; C064196:dpp protein, Drosophila; C113278:ey protein, Drosophila; C092694:eya protein, Drosophila; C108704:hth protein, Drosophila; C074622:wg protein, Drosophila; C066830:tsh protein, Drosophila; C077245:hh protein, Drosophila