Home > Conference materials > Papers > CDC25A is able to induce resumption of meiosis but compromises metaphase I-metaphase II transition in mouse oocytes
Original title:
CDC25A is able to induce resumption of meiosis but compromises metaphase I-metaphase II transition in mouse oocytes
Translated title:
CDC25A je schopna indukovat znovuzahájení meiosy, ale inhibuje metafase I – metafase II přechod
Authors:
Šolc, Petr ; Šašková, Adéla ; Baran, V. ; Kubelka, Michal ; Motlík, Jan Document type: Papers Conference/Event: Conference on Reproductive and Developmental Biology, Praha (CZ), 2007-06-21 / 2007-06-22
Year:
2007
Language:
eng Abstract:
[eng][cze] We have shown that CDC25A protein is expressed in GV-stage oocytes but decreases, in CDK1-dependent manner, during meiotic maturation. As compared with GV-stage only a very low level of CDC25A protein is present at metaphase I (MI) and metaphase II (MII) stages. CDC25A mRNA is stable during entire meiotic maturation. Exogenous CDC25A was sufficient to overcome cAMP-mediated GV-stage block. Using microinjection of GFP-CDC25A and GFP-CDC25B mRNAs constructs we have revealed that CDC25A is exclusively nuclear protein until nuclear envelope break down (NEBD). In contrast CDC25B localizes to cytoplasm at GV-stage oocytes and translocates to nucleus shortly before NEBD. Overexpression of GFP-CDC25A, to interfere with CDC25A degradation during meiotic maturation, resulted in MI block characterized with problems in chromosome congression and spindle formation. This MI block was accompanied with the transient reduction of both CDK1 and MAPK activities. RNAi mediated CDC25A knock-down resulted in a reduced ability to resume meiosis and to reach MII. These data demonstrate that behavior of CDC25A during female meiosis differs significantly from mitosis and CDC25A is involved in both, resumption of meiosis and also in metaphase I spindle formation as a prerequisite for correct MI-MII transition. It is evident that CDC25B is not only important CDC25 phosphatase for meiotic maturation but also CDC25A has its meiotic specific role.Práce se zabývá expresí a funkcí CDC25A v myších oocytech. Bylo zjištěno, že CDC25A protein se exprimuje v GV-oocytech, avšak jeho hladina při meiotickém zrání klesá, přičemž na konci meiosy je v metafase II oocytech pouze velmi nízká hladina CDC25A proteinu. Tento CDC25A proteinový pokles je závislý na CDK1 aktivitě, nesouvisí však se změnami hladiny Cdc25A mRNA, která zůstává konstantní. Pomocí funkčních studií (RNA interference, mikroinjekce mRNA) jsme jasně prokázali, že CDC25A je nezbytná pro znovuzahájení meiosy a tvorbu metafase I spindelu. Pokles CDC25A aktivity po znovuzahájení meiosy je klíčový pro korektní metafase I – metafase II přechod.
Keywords:
meiosis Project no.: CEZ:AV0Z50450515 (CEP) Host item entry: Programme and book of abstracts of Conference on Reproductive and Developmental Biology
Institution: Institute of Animal Physiology and Genetics AS ČR
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Document availability information: Fulltext is available at the institute of the Academy of Sciences. Original record: http://hdl.handle.net/11104/0150549