title: Transcriptional regulation of the Drosophila homeotic gene teashirt by the homeodomain protein Fushi tarazu.
abstract: The Drosophila melanogaster gene teashirt (tsh) is essential for segment identity of the embryonic thorax and abdomen. A deletion 3' to the tsh transcription unit causes the loss of tsh early expression in the even-numbered parasegments, and the corresponding larval cuticular patterns are disrupted. tsh function in the odd-numbered parasegments in these mutants is normal by both criteria. The in vivo activities of genomic fragments from the deleted region were tested in transgenic embryos. A 2.0 kb enhancer from the 3' region acts mainly in the even-numbered parasegments and is dependent on fushi tarazu (ftz) activity, which encodes a homeodomain protein required for the development of even-numbered parasegments. Ftz protein binds in vitro to four distinct sequences in a 220 bp sub-fragment; these and neighboring sequences are conserved in the equivalent enhancer isolated from Drosophila virilis. Tsh protein produced under the control of the 220 bp enhancer partially rescues a null tsh mutation, with its strongest effect in the even-numbered parasegments. Mutation of the Ftz binding sites partially abrogates the capacity for rescue. These results suggest a composite mechanism for regulation of tsh, with different activators such as ftz contributing to the overall pattern of expression of this key regulator.
authors.affiliation: Laboratoire de Génétique et Physiologie du Développement, UMR 9943 C.N.R.S.-Université, I.B.D.M. CNRS-INSERM-Université de la Méditerranée, Marseille, France.
authors.forename: N
authors.initials: N
authors.lastname: Coré
authors.forename: B
authors.initials: B
authors.lastname: Charroux
authors.forename: A
authors.initials: A
authors.lastname: McCormick
authors.forename: C
authors.initials: C
authors.lastname: Vola
authors.forename: L
authors.initials: L
authors.lastname: Fasano
authors.forename: M P
authors.initials: MP
authors.lastname: Scott
authors.forename: S
authors.initials: S
authors.lastname: Kerridge
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian; D004742:Enhancer Elements, Genetic; D051717:Fushi Tarazu Transcription Factors; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C497169:ftz protein, Drosophila; C066830:tsh protein, Drosophila