title: Involvement of co-repressors Groucho and CtBP in the regulation of single-minded in Drosophila.
abstract: Dorso-ventral patterning results in the establishment of the two germ layers in the Drosophila embryo, mesoderm and mesectoderm, that are separated by a strip of cells giving rise to the mesectoderm and eventually to the ventral midline. The mesectoderm is specified by the expression of single-minded (sim) which is activated through the concerted action of Dorsal and Twist in addition to a Notch signal. In the mesoderm, sim is repressed by Snail together with the co-repressor C-terminal binding protein (CtBP). Here, we address the involvement of the two co-repressors CtBP and Groucho (Gro) in repression of sim in the neuroectoderm. It was shown earlier that sim is restricted in the neuroectoderm with help of Suppressor of Hairless [Su(H)] and Hairless. Using the female sterile technique, we generated germ line clones deficient for Gro, CtBP or Hairless and assayed sim mRNA relative to snail mRNA expression. We show that sim repression requires both co-repressors Gro and CtBP to be fully repressed in the neuroectoderm, suggesting that a repression complex is assembled including Su(H) and Hairless as was shown for other Notch target genes before. Moreover, our work implies that Gro is important for the repression of sim specifically within the mesoderm anlagen, indicating that Snail and CtBP are insufficient to entirely silence sim in this germ layer.
authors.affiliation: Universität Hohenheim, Institut für Genetik, Stuttgart, Germany.
authors.forename: Anja C
authors.initials: AC
authors.lastname: Nagel
authors.forename: Irmgard
authors.initials: I
authors.lastname: Wech
authors.forename: Daniela
authors.initials: D
authors.lastname: Schwinkendorf
authors.forename: Anette
authors.initials: A
authors.lastname: Preiss
mesh_terms: D000429:Alcohol Oxidoreductases / Q000502:physiology*; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D054258:Neural Plate / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D012097:Repressor Proteins / Q000502:physiology*; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000502:physiology
chemical_list: D000429:Alcohol Oxidoreductases; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; C088731:Su(H) protein, Drosophila; C091023:gro protein, Drosophila; C089449:sim protein, Drosophila; C000604451:sna protein, Drosophila; C076560:H protein, Drosophila; C096794:C-terminal binding protein