title: Embryo development. A cysteine-clamp gene drives embryo polarity in the midge Chironomus.
abstract: In the fruit fly Drosophila, head formation is driven by a single gene, bicoid, which generates head-to-tail polarity of the main embryonic axis. Bicoid deficiency results in embryos with tail-to-tail polarity and no head. However, most insects lack bicoid, and the molecular mechanism for establishing head-to-tail polarity is poorly understood. We have identified a gene that establishes head-to-tail polarity of the mosquito-like midge, Chironomus riparius. This gene, named panish, encodes a cysteine-clamp DNA binding domain and operates through a different mechanism than bicoid. This finding, combined with the observation that the phylogenetic distributions of panish and bicoid are limited to specific families of flies, reveals frequent evolutionary changes of body axis determinants and a remarkable opportunity to study gene regulatory network evolution.
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Klomp
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Athy
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Chun Wai
authors.initials: CW
authors.lastname: Kwan
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Natasha I
authors.initials: NI
authors.lastname: Bloch
authors.affiliation: Division of Signaling and Functional Genomics, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sandmann
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Steffen
authors.initials: S
authors.lastname: Lemke
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA. uschmid@uchicago.edu.
authors.forename: Urs
authors.initials: U
authors.lastname: Schmidt-Ott
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002683:Chironomidae / Q000196:embryology* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000196:embryology*; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D018398:Homeodomain Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary / Q000235:genetics; D015534:Trans-Activators / Q000145:classification / Q000235:genetics / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D015534:Trans-Activators; C056478:bcd protein, Drosophila