transforming-growth-factor-alpha and Ovarian-Cysts

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.

Topics: Animals; Base Sequence; Body Patterning; Cell Differentiation; Cytoplasm; DEAD-box RNA Helicases; Drosophila; Drosophila Proteins; Female; Insect Proteins; Molecular Sequence Data; Oocytes; Oogenesis; Ovarian Cysts; RNA Helicases; RNA Nucleotidyltransferases; RNA, Messenger; Sequence Deletion; Transforming Growth Factor alpha; Transforming Growth Factors