Mammalian oocytes are arrested at prophase I until puberty when luteinizing hormone (LH) induces resumption of meiosis of follicle-enclosed oocytes. Resumption of meiosis is tightly coupled with regulating cyclin-dependent kinase 1 (CDK1) activity. Prophase I arrest depends on inhibitory phosphorylation of CDK1 and anaphase-promoting complex-(APC-CDH1)-mediated regulation of cyclin B levels. Prophase I arrest is maintained by endogenously produced cyclic adenosine monophosphate (cAMP), which activates protein kinase A (PKA) that in turn phosphorylates (and activates) the nuclear kinase WEE2. In addition, PKA-mediated phosphorylation of the phosphatase CDC25B results in its cytoplasmic retention. The combined effect maintains low levels of CDK1 activity that are not sufficient to initiate resumption of meiosis. LH triggers synthesis of epidermal growth factor-like factors in mural granulosa cells and leads to reduced cGMP transfer from cumulus cells to oocytes via gap junctions that couple the two cell types. cGMP inhibits oocyte phosphodiesterase 3A (PDE3A) and a decline in oocyte cGMP results in increased PDE3A activity. The ensuing decrease in oocyte cAMP triggers maturation by alleviating the aforementioned phosphorylations of WEE2 and CDC25B. As a direct consequence CDC25B translocates into the nucleus. The resulting activation of CDK1 also promotes extrusion of WEE2 from the nucleus thereby providing a positive amplification mechanism for CDK1 activation. Other kinases, e.g. protein kinase B, Aurora kinase A and polo-like kinase 1, also participate in resumption of meiosis. Mechanisms governing meiotic prophase I arrest and resumption of meiosis share common features with DNA damage-induced mitotic G2-checkpoint arrest and checkpoint recovery, respectively. These common features include CDC14B-dependent activation of APC-CDH1 in prophase I arrested oocytes or G2-arrested somatic cells, and CDC25B-dependent cell cycle resumption in both oocytes and somatic cells.

• MeSH
• AMP cyklický metabolismus   MeSH
• anafázi podporující komplex MeSH
• Cdh1 proteiny MeSH
• cyklin B1 metabolismus   MeSH
• epidermální růstový faktor metabolismus   MeSH
• G2 fáze * MeSH
• inhibiční proteiny cyklin-dependentních kinas metabolismus   MeSH
• komplexy ubikvitinligas metabolismus   MeSH
• meióza * MeSH
• metafáze MeSH
• myši MeSH
• oocyty metabolismus   MeSH
• oogeneze * MeSH
• profáze meiózy I MeSH
• proliferace buněk * MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• signální transdukce * MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• AMP cyklický MeSH
• anafázi podporující komplex MeSH
• Ccnb1 protein, mouse MeSH Prohlížeč
• Cdh1 proteiny MeSH
• cyklin B1 MeSH
• epidermální růstový faktor MeSH
• Fzr1 protein, mouse MeSH Prohlížeč
• inhibiční proteiny cyklin-dependentních kinas MeSH
• komplexy ubikvitinligas MeSH
• proteiny buněčného cyklu MeSH

During oocyte growth the cell accumulates RNAs to contribute to oocyte and embryo development which progresses with ceased transcription. To investigate the subcellular distribution of specific RNAs and their translation we developed a technique revealing several instances of localized translation with distinctive regulatory implications. We analyzed the localization and expression of candidate non-coding and mRNAs in the mouse oocyte and embryo. Furthermore, we established simultaneous visualization of mRNA and in situ translation events validated with polysomal occupancy. We discovered that translationally dormant and abundant mRNAs CyclinB1 and Mos are localized in the cytoplasm of the fully grown GV oocyte forming cloud-like structures with consequent abundant translation at the center of the MII oocyte. Coupling detection of the localization of specific single mRNA molecules with their translation at the subcellular context is a valuable tool to quantitatively study temporal and spatial translation of specific target mRNAs to understand molecular processes in the developing cell.

• Klíčová slova
• imaging, localization, mRNA, subcellular, translation,
• MeSH
• cyklin B1 genetika   MeSH
• cytoplazma genetika   MeSH
• embryo savčí chemie   MeSH
• hybridizace in situ fluorescenční MeSH
• messenger RNA genetika   MeSH
• myši MeSH
• nekódující RNA genetika   MeSH
• oocyty chemie   růst a vývoj   MeSH
• polyribozomy genetika   MeSH
• proteosyntéza MeSH
• protoonkogenní proteiny c-mos genetika   MeSH
• vývojová regulace genové exprese MeSH
• zobrazení jednotlivé molekuly metody   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Ccnb1 protein, mouse MeSH Prohlížeč
• cyklin B1 MeSH
• messenger RNA MeSH
• nekódující RNA MeSH
• protoonkogenní proteiny c-mos MeSH