title: Posttranscriptional regulation in Drosophila oocytes and early embryos.
abstract: Molecular asymmetries underlying embryonic axis patterning and germ cell specification are established in Drosophila largely by position-dependent translational regulation of maternally expressed messenger RNAs. Here, I review several mechanisms of posttranscriptional regulation in the Drosophila oocyte and syncytial embryo, and how they relate to embryonic patterning, with a strong emphasis on the most recent advances in the area. The review is not exhaustive, but focuses on examples that illustrate the interplay between specific regulatory events and the general metabolic machinery that governs translation and mRNA stability. Biophysical investigations into how the Bicoid gradient is formed are discussed, as are the elaborate mechanisms controlling how the Oskar and Nanos proteins become restricted to the posterior pole of the embryo. Work on Vasa, a translational activator of some germ line mRNAs and on 4EHP, a negative regulator that unproductively binds the 5' cap structure of target mRNAs, is also briefly reviewed. Finally, the emerging understanding of the role of microRNAs in regulating translation of germ line mRNAs is also discussed.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada. paul.lasko@mcgill.ca
authors.forename: Paul
authors.initials: P
authors.lastname: Lasko
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D016764:Cell Polarity; D003595:Cytoplasmic Streaming; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics / Q000378:metabolism; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D014176:Protein Biosynthesis; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D039561:Eukaryotic Initiation Factor-4E; D018398:Homeodomain Proteins; D035683:MicroRNAs; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C056478:bcd protein, Drosophila; C084564:cad protein, Drosophila; C504669:eIF4EHP protein, Drosophila; C061245:hb protein, Drosophila; C091675:osk protein, Drosophila; C070574:nos protein, Drosophila; C088269:vas protein, Drosophila; D053487:DEAD-box RNA Helicases