title: Bicoid-independent formation of thoracic segments in Drosophila.
abstract: The maternal determinant Bicoid (Bcd) represents the paradigm of a morphogen that provides positional information for pattern formation. However, as bicoid seems to be a recently acquired gene in flies, the question was raised as to how embryonic patterning is achieved in organisms with more ancestral modes of development. Because the phylogenetically conserved Hunchback (Hb) protein had previously been shown to act as a morphogen in abdominal patterning, we asked which functions of Bcd could be performed by Hb. By reestablishing a proposed ancient regulatory circuitry in which maternal Hb controls zygotic hunchback expression, we show that Hb is able to form thoracic segments in the absence of Bcd.
authors.affiliation: Lehrstuhl Genetik, Universität Bayreuth, 95447 Bayreuth, Germany.
authors.forename: E A
authors.initials: EA
authors.lastname: Wimmer
authors.forename: A
authors.initials: A
authors.lastname: Carleton
authors.forename: P
authors.initials: P
authors.lastname: Harjes
authors.forename: T
authors.initials: T
authors.lastname: Turner
authors.forename: C
authors.initials: C
authors.lastname: Desplan
mesh_terms: D000818:Animals; D019521:Body Patterning; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D029721:Drosophila Proteins; D047108:Embryonic Development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D008297:Male; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic; D013909:Thorax / Q000196:embryology; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D019076:Transgenes; D016335:Zinc Fingers; D015053:Zygote / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D019476:Insect Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C056478:bcd protein, Drosophila; C084564:cad protein, Drosophila; C061245:hb protein, Drosophila