The role of BicD, Egl, Orb and the microtubules in the restriction of meiosis to the Drosophila oocyte.
The oocyte is the only cell in Drosophila that goes through meiosis with meiotic recombination, but several germ cells in a 16-cell cyst enter meiosis and form synaptonemal complexes (SC) before one cell is selected to become the oocyte. Using an antibody that recognises a component of the SC or the synapsed chromosomes, we have analysed how meiosis becomes restricted to one cell, in relation to the other events in oocyte determination. Although BicD and egl mutants both cause the development of cysts with no oocyte, they have opposite effects on the behaviour of the SC: none of the cells in the cyst form SC in BicD null mutants, whereas all of the cells do in egl and orb mutants. Furthermore, unlike all cytoplasmic markers for the oocyte, the SC still becomes restricted to one cell when the microtubules are depolymerised, even though the BicD/Egl complex is not localised. These results lead us to propose a model in which BicD, Egl and Orb control entry into meiosis by regulating translation.
Huynh
J R
JR
The Wellcome/CRC Institute and the Department of Genetics, University of Cambridge, Tennis Court Rd, Cambridge, CB2 1QR, UK.
St Johnston
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D000483:Alleles; D000818:Animals; D000906:Antibodies; D015415:Biomarkers; D003593:Cytoplasm / Q000378:metabolism; D003703:Demecolcine / Q000494:pharmacology; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins; D004527:Egg Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D008870:Microtubules / Q000502:physiology*; D009154:Mutation; D009865:Oocytes / Q000502:physiology*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D011995:Recombination, Genetic; D013573:Synaptonemal Complex / Q000502:physiology; D013997:Time Factors
D000906:Antibodies; C061998:BicD protein, Drosophila; D015415:Biomarkers; D029721:Drosophila Proteins; D004527:Egg Proteins; D019476:Insect Proteins; D016601:RNA-Binding Proteins; C104613:egl protein, Drosophila; C089932:orb protein, Drosophila; C114493:spn-B protein, Drosophila; D003703:Demecolcine