3' non-translated sequences in Drosophila cyclin B transcripts direct posterior pole accumulation late in oogenesis and peri-nuclear association in syncytial embryos.
We have characterised forms of the Drosophila cyclin B transcript that differ as a result of a splicing event which removes a nucleotide segment from the 3' untranslated region. In oogenesis, both cyclin A RNA and a shorter form of the cyclin B transcript are seen in the cells of the germarium that are undergoing mitosis. The shorter cyclin B transcript alone is then detectable in the presumptive oocyte until stages 7-8 of oogenesis. Both cyclin A RNA and a longer form of the cyclin B RNA are then synthesised in the nurse cells during stages 9-11, to be deposited in the oocyte during stages 11-12. These transcripts become evenly distributed throughout the oocyte cytoplasm but, in addition, those of cyclin B become concentrated at the posterior pole. Examination of the distributions of RNAs transcribed from chimeric cyclin genes indicates that sequences in the 3' untranslated region of the larger cyclin B RNA are required both for it to become concentrated at the posterior pole and to direct those transcripts in the body of the syncytial embryo to their peri-nuclear localisation. These sequences are disrupted by the splicing event which generates smaller cyclin B transcripts.
Dalby
B
B
Department of Biochemistry, The University, Dundee, Scotland.
Glover
D M
DM
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology*; D016213:Cyclins / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D015336:Molecular Probe Techniques; D009866:Oogenesis / Q000235:genetics*; D010053:Ovary / Q000502:physiology; D014158:Transcription, Genetic / Q000235:genetics*
D016213:Cyclins