title: Molecular analysis of EMS-induced frizzled mutations in Drosophila melanogaster.
abstract: The frizzled (fz) gene of Drosophila is essential for the development of normal tissue polarity in the adult cuticle of Drosophila. In fz mutants the parallel array of hairs and bristles that decorate the cuticle is disrupted. Previous studies have shown the fz encodes a membrane protein with seven putative transmembrane domains, and that it has a complex role in the development of tissue polarity, as there exist both cell-autonomous and cell nonautonomous alleles. We have now examined a larger number of alleles and found that 15 of 19 alleles display cell nonautonomy. We have examined these and other alleles by Western blot analysis and found that most fz mutations result in altered amounts of Fz protein, and many also result in a Fz protein that migrates aberrantly in SDS-PAGE. We have sequenced a subset of these alleles. Cell nonautonomous fz alleles were found to be associated with mutations that altered amino acids in all regions of the Fz protein. Notably, the four cell-autonomous mutations were all in a proline residue located in the presumptive first cytoplasmic loop of the protein. We have also cloned and sequenced the fz gene from D. virilis. Conceptual translation of the D. virilis open reading frame indicates that the Fz protein is unusually well conserved. Indeed, in the putative cytoplasmic domains the Fz proteins of the two species are identical.
authors.affiliation: Biology Department, University of Virginia, Charlottesville 22903, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Jones
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: P N
authors.initials: PN
authors.lastname: Adler
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D005020:Ethyl Methanesulfonate; D051157:Frizzled Receptors; D017344:Genes, Insect; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009153:Mutagens; D009154:Mutation; D051381:Rats; D043562:Receptors, G-Protein-Coupled; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; D051157:Frizzled Receptors; D008565:Membrane Proteins; D009153:Mutagens; D043562:Receptors, G-Protein-Coupled; C058784:fz protein, Drosophila; D005020:Ethyl Methanesulfonate