title: The presumptive R7 cell of the developing Drosophila eye receives positional information independent of sevenless, boss and sina.
abstract: Studies on the development of the R7 photoreceptor in the Drosophila eye thus far have identified three genes that specifically affect this cell: sevenless, boss and sina. In each of these mutants the R7 precursor develops instead as the equatorial cone cell (EQC). We have isolated an enhancer trap line, H214, in which beta-galactosidase is primarily expressed in the R7 cell throughout its development. In mutations of sevenless, boss and sina, expression in H214 is initially reduced although still present in the R7 precursor and persists in the EQC into which it develops. The EQC in wild type never expresses lacZ in H214. This result is in contrast to that seen with other enhancer trap lines that display expression in R7, and indicates that some aspect of R7 differentiation is independent of the genetic pathway(s) involving sevenless, boss and sina.
authors.affiliation: Howard Hughes Medical Institute, Berkeley, CA.
authors.forename: M
authors.initials: M
authors.lastname: Mlodzik
authors.forename: Y
authors.initials: Y
authors.lastname: Hiromi
authors.forename: C S
authors.initials: CS
authors.lastname: Goodman
authors.forename: G M
authors.initials: GM
authors.lastname: Rubin
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D005123:Eye / Q000166:cytology / Q000196:embryology*; D005136:Eye Proteins / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D005796:Genes; D007814:Larva; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D010786:Photoreceptor Cells / Q000196:embryology*; D011679:Pupa; D020794:Receptor Protein-Tyrosine Kinases; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins
chemical_list: D029721:Drosophila Proteins; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; C072141:boss protein, Drosophila; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins; D020794:Receptor Protein-Tyrosine Kinases; C056737:sev protein, Drosophila