title: Dorsal-ventral midline signaling in the developing Drosophila eye.
abstract: Boundaries between different cell types play key roles in many developmental patterning processes. They can be established by various mechanisms, and signaling between the different cell types can occur in a number of ways. One mechanism of crossboundary signaling is controlled by the Notch (N)-modifying protein Fringe (Fng). At the Drosophila wing dorsal-ventral (D-V) border, the mechanism by which an Fng(+)-Fng(-) interface controls local N activation has been well characterized. A similar N-activating Fng(+)-Fng(-) interface has also been described at the D-V border of the fly eye, but the mechanisms that establish and regulate it are different from those in the wing. Here we describe the ventral role of the Sloppy-paired (Slp) transcription factor, and its interactions with dorsally expressed Iroquois (Iro) transcription factors in the regulation of signaling about the Fng(+)-Fng(-) interface in the developing eye. The two transcription factors are mutually repressive and initially abut at the D-V midline. However, N signaling at the interface downregulates Slp expression, and a gap opens between the two expression domains in which Serrate (Ser, an N ligand) is upregulated.
authors.affiliation: Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 West 168th St, HHSC 1120, New York, NY 10032, USA.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sato
authors.forename: Andrew
authors.initials: A
authors.lastname: Tomlinson
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000502:physiology; D004627:Embryonic Induction; D005123:Eye / Q000196:embryology / Q000254:growth & development*; D018398:Homeodomain Proteins / Q000502:physiology; D017351:N-Acetylglucosaminyltransferases / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C099258:caup protein, Drosophila; C074838:slp1 protein, Drosophila; C074839:slp2 protein, Drosophila; D017351:N-Acetylglucosaminyltransferases; C090576:fng protein, Drosophila