vasa is required for GURKEN accumulation in the oocyte, and is involved in oocyte differentiation and germline cyst development.
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.
Styhler
S
S
Department of Biology, McGill University, Montréal, Quèbec, Canada H3A 1B1, Canada.
Nakamura
A
A
Swan
A
A
Suter
B
B
Lasko
P
P
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
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