Encore is a member of a novel family of proteins and affects multiple processes in Drosophila oogenesis.
Mutations in the encore (enc) gene of Drosophila melanogaster cause one extra round of mitosis in the germline, resulting in the formation of egg chambers with extra nurse cells. In addition, enc mutations affect the accumulation of Gurken protein within the oocyte, leading to the production of ventralized eggs. Here we show that enc mutants also exhibit abnormalities in karyosome morphology, similar to other ventralizing mutants such as okra and spindle B. Unlike these mutants, however, the defects in Gurken accumulation and karyosome formation do not result from activation of a meiotic checkpoint. Furthermore, we demonstrate that the requirement for enc in these processes is temporally distinct from its role in germline mitosis. Cloning of the enc locus and generation of anti-Enc antibodies reveal that enc encodes a large novel protein that accumulates within the oocyte cytoplasm and colocalizes with grk mRNA. We argue that the enc mutant phenotypes reflect a role for Enc in the regulation of several RNA targets.
Van Buskirk
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Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton NJ 08544, USA. gschupbach@molbio. princeton.edu
Hawkins
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Schüpbach
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D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002467:Cell Nucleus / Q000648:ultrastructure; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D004527:Egg Proteins / Q000235:genetics* / Q000502:physiology*; D005260:Female; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics* / Q000502:physiology*; D008540:Meiosis / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D009866:Oogenesis / Q000235:genetics / Q000502:physiology*; D014176:Protein Biosynthesis; D017386:Sequence Homology, Amino Acid; D016211:Transforming Growth Factor alpha; D015291:Transforming Growth Factors / Q000235:genetics
D017931:DNA Primers; D029721:Drosophila Proteins; D004527:Egg Proteins; D019476:Insect Proteins; D016211:Transforming Growth Factor alpha; C417220:enc protein, Drosophila; C083730:grk protein, Drosophila; C091675:osk protein, Drosophila; D015291:Transforming Growth Factors