title: The irregular chiasm C-roughest locus of Drosophila, which affects axonal projections and programmed cell death, encodes a novel immunoglobulin-like protein.
abstract: The axonal projection mutations irregular chiasm C of Drosophila melanogaster comap and genetically interact with the roughest locus, which is required for programmed cell death in the developing retina. We cloned the genomic region in 3C5 by transposon tagging and identified a single transcription unit that produces a major, spatially and temporally regulated mRNA species of approximately 5.0 kb. Postembryonic expression is strong in the developing optic lobe and in the eye imaginal disc. The gene encodes a transmembrane protein of 764 amino acids with five extracellular immunoglobulin-like domains and similarity to the chicken axonal surface glycoprotein DM-GRASP/SC1/BEN. Both known irreC alleles reduce the level of transcription, whereas the roughestCT mutation disrupts the intracellular domain of the protein.
authors.affiliation: Institut für Biologie III, Albert-Ludwigs Universität, Freiburg im Breisgau, Germany.
authors.forename: R G
authors.initials: RG
authors.lastname: Ramos
authors.forename: G L
authors.initials: GL
authors.lastname: Igloi
authors.forename: B
authors.initials: B
authors.lastname: Lichte
authors.forename: U
authors.initials: U
authors.lastname: Baumann
authors.forename: D
authors.initials: D
authors.lastname: Maier
authors.forename: T
authors.initials: T
authors.lastname: Schneider
authors.forename: J H
authors.initials: JH
authors.lastname: Brandstätter
authors.forename: A
authors.initials: A
authors.lastname: Fröhlich
authors.forename: K F
authors.initials: KF
authors.lastname: Fischbach
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001369:Axons / Q000502:physiology; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005136:Eye Proteins; D017344:Genes, Insect / Q000235:genetics* / Q000502:physiology; D007136:Immunoglobulins / Q000737:chemistry; D007301:Insect Hormones / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology; D009897:Optic Chiasm / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; D005136:Eye Proteins; D007136:Immunoglobulins; D007301:Insect Hormones; C085209:rst protein, Drosophila