title: vasa is required for GURKEN accumulation in the oocyte, and is involved in oocyte differentiation and germline cyst development.
abstract: The Drosophila gene vasa is required for pole plasm assembly and function, and also for completion of oogenesis. To investigate the role of vasa in oocyte development, we generated a new null mutation of vasa, which deletes the entire coding region. Analysis of vasa-null ovaries revealed that the gene is involved in the growth of germline cysts. In vasa-null ovaries, germaria are atrophied, and contain far fewer developing cysts than do wild-type germaria; a phenotype similar to, but less severe than, that of a null nanos allele. The null mutant also revealed roles for vasa in oocyte differentiation, anterior-posterior egg chamber patterning, and dorsal-ventral follicle patterning, in addition to its better-characterized functions in posterior embryonic patterning and pole cell specification. The anterior-posterior and dorsal-ventral patterning phenotypes resemble those observed in gurken mutants. vasa-null oocytes fail to efficiently accumulate many localized RNAs, such as Bicaudal-D, orb, oskar, and nanos, but still accumulate gurken RNA. However, GRK accumulation in the oocyte is severely reduced in the absence of vasa function, suggesting a function for VASA in activating gurken translation in wild-type ovaries.
authors.affiliation: Department of Biology, McGill University, Montréal, Quèbec, Canada H3A 1B1, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Styhler
authors.forename: A
authors.initials: A
authors.lastname: Nakamura
authors.forename: A
authors.initials: A
authors.lastname: Swan
authors.forename: B
authors.initials: B
authors.lastname: Suter
authors.forename: P
authors.initials: P
authors.lastname: Lasko
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D002454:Cell Differentiation; D003593:Cytoplasm / Q000737:chemistry; D053487:DEAD-box RNA Helicases; D004330:Drosophila / Q000166:cytology*; D029721:Drosophila Proteins; D005260:Female; D019476:Insect Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009865:Oocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology*; D010048:Ovarian Cysts / Q000235:genetics*; D020365:RNA Helicases; D012316:RNA Nucleotidyltransferases / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D017384:Sequence Deletion; D016211:Transforming Growth Factor alpha; D015291:Transforming Growth Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029721:Drosophila Proteins; D019476:Insect Proteins; D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha; C083730:grk protein, Drosophila; D015291:Transforming Growth Factors; D012316:RNA Nucleotidyltransferases; C088269:vas protein, Drosophila; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases