title: Formation of the Drosophila ovarian ring canal inner rim depends on cheerio.
abstract: In Drosophila oogenesis, the development of a mature oocyte depends on having properly developed ring canals that allow cytoplasm transport from the nurse cells to the oocyte. Ring canal assembly is a step-wise process that transforms an arrested cleavage furrow into a stable intercellular bridge by the addition of several proteins. Here we describe a new gene wc named cheerio that provides a critical function for ring canal assembly. Mutants in cheerio fail to localize ring canal inner rim proteins including filamentous actin, the ring canal-associated products from the hu-li tai shao (hts) gene, and kelch. Since hts and kelch are present but unlocalized in cheerio mutant cells, cheerio is likely to function upstream from each of them. Examination of mutants in cheerio places it in the pathway of ring canal assembly between cleavage furrow arrest and localization of hts and actin filaments. Furthermore, this mutant reveals that the inner rim cytoskeleton is required for expansion of the ring canal opening and for plasma membrane stabilization.
authors.affiliation: Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 05610, USA.
authors.forename: D N
authors.initials: DN
authors.lastname: Robinson
authors.forename: T A
authors.initials: TA
authors.lastname: Smith-Leiker
authors.forename: N S
authors.initials: NS
authors.lastname: Sokol
authors.forename: A M
authors.initials: AM
authors.lastname: Hudson
authors.forename: L
authors.initials: L
authors.lastname: Cooley
mesh_terms: D000199:Actins / Q000378:metabolism; D000483:Alleles; D000818:Animals; D002148:Calmodulin-Binding Proteins / Q000235:genetics / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism; D002450:Cell Communication; D002462:Cell Membrane / Q000378:metabolism; D002874:Chromosome Mapping; D003599:Cytoskeleton / Q000648:ultrastructure*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000033:anatomy & histology* / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D007247:Infertility, Female / Q000235:genetics / Q000473:pathology; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D007365:Intercellular Junctions / Q000648:ultrastructure*; D008840:Microfilament Proteins; D009865:Oocytes / Q000166:cytology; D010053:Ovary / Q000166:cytology* / Q000378:metabolism
chemical_list: D000199:Actins; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D008840:Microfilament Proteins; C108208:hts protein, Drosophila; C080353:kel protein, Drosophila