Chicken blastodermal cells (stage X) were fused to mouse enucleated oocytes with either no or high maturation promoting factor (MPF) activity. High MPF levels always induced premature chromosome condensation (PCC) irrespective of the number of nuclei fused to a single oocyte. When a single blastodermal cell was fused to a single oocyte without MPF activity the nucleus remained intact for up to 3 h and thereafter underwent PCC. A quite different situation was observed after multiple fusion of several blastodermal cells to a single oocyte without MPF activity. Here, the transplanted nuclei remained intact even after prolonged culture but underwent extensive swelling. DNA synthesis was detected in almost all unfused blastodermal cells. However, after the fusion of several blastodermal cells to a single oocyte no DNA synthesis could be detected. These results provide further evidence that MPF is the universal cell-cycle regulator in the animal kingdom. Its activity is blocked (or neutralised) after fusion to several S-phase cells. Interestingly, our results further suggest that DNA synthesis is suppressed in meiotic cytoplasm even in the presence of an intact nuclear envelope.

• MeSH
• blastoderm ultrastruktura   MeSH
• buněčné jádro účinky léků   MeSH
• chromatin ultrastruktura   MeSH
• faktor podporující zrání farmakologie   MeSH
• hybridní buňky ultrastruktura   MeSH
• kuřecí embryo MeSH
• meióza fyziologie   MeSH
• mezotelin MeSH
• myši inbrední ICR MeSH
• myši MeSH
• oocyty ultrastruktura   MeSH
• replikace DNA MeSH
• S fáze fyziologie   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromatin MeSH
• faktor podporující zrání MeSH
• mezotelin MeSH
• Msln protein, mouse MeSH Prohlížeč

The method of polyethylene-glycol-induced fusion of mammalian oocytes was applied to study maturation-promoting factor (MPF) activity. After homologous fusions of one maturing--late diakinesis (LD), metaphase I (MI)--pig or mouse oocyte to one, two, or three immature-germinal vesicle (GV)--oocytes, giant cells were cultured in control or cycloheximide supplemented medium for 3 hours. The occurrence of germinal vesicle breakdown (GVBD) and premature chromosome condensation (PCC) served as a control of MPF activity. In giant cells composed of one maturing and one, two or three immature oocytes, GVBD and PCC were observed in all cases after cultivation in the control medium. In the presence of cycloheximide, the completion of GVBD and PCC remained high when one maturing and one immature oocyte were fused (83.7% and 95.7% of GVBD in pig and mouse, respectively). However, in giant cells composed of one maturing and up to three immature oocytes, all GVs were broken down only occasionally (4.8% and 11.7% in pig and mouse, respectively). These results suggest that in pig and mouse oocytes MPF does not amplify autocatalytically, but requires active protein synthesis for its production.

• MeSH
• chromozomy účinky léků   MeSH
• cykloheximid farmakologie   MeSH
• faktor podporující zrání MeSH
• fúze buněk MeSH
• mezotelin MeSH
• myši MeSH
• oocyty účinky léků   fyziologie   MeSH
• oogeneze účinky léků   MeSH
• prasata MeSH
• Rana pipiens MeSH
• růstové látky biosyntéza   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cykloheximid MeSH
• faktor podporující zrání MeSH
• mezotelin MeSH
• Msln protein, mouse MeSH Prohlížeč
• růstové látky MeSH

In mammalian females, oocytes are stored in the ovary and meiosis is arrested at the diplotene stage of prophase I. When females reach puberty oocytes are selectively recruited in cycles to grow, overcome the meiotic arrest, complete the first meiotic division and become mature (ready for fertilization). At a molecular level, the master regulator of prophase I arrest and meiotic resumption is the maturation-promoting factor (MPF) complex, formed by the active form of cyclin dependent kinase 1 (CDK1) and Cyclin B1. However, we still do not have complete information regarding the factors implicated in MPF activation. In this study we document that out of three mammalian serum-glucocorticoid kinase proteins (SGK1, SGK2, SGK3), mouse oocytes express only SGK1 with a phosphorylated (active) form dominantly localized in the nucleoplasm. Further, suppression of SGK1 activity in oocytes results in decreased CDK1 activation via the phosphatase cell division cycle 25B (CDC25B), consequently delaying or inhibiting nuclear envelope breakdown. Expression of exogenous constitutively active CDK1 can rescue the phenotype induced by SGK1 inhibition. These findings bring new insights into the molecular pathways acting upstream of MPF and a better understanding of meiotic resumption control by presenting a new key player SGK1 in mammalian oocytes.

• Klíčová slova
• CDK1, MPF, Meiosis, Nuclear envelope breakdown, Oocyte, SGK1,
• MeSH
• faktor podporující zrání * metabolismus   MeSH
• kontrolní body buněčného cyklu MeSH
• meióza MeSH
• myši MeSH
• oocyty metabolismus   MeSH
• profáze meiózy I MeSH
• protein-serin-threoninkinasy genetika   MeSH
• proteiny bezprostředně časné * genetika   metabolismus   MeSH
• savci metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktor podporující zrání * MeSH
• protein-serin-threoninkinasy MeSH
• proteiny bezprostředně časné * MeSH
• serum-glucocorticoid regulated kinase MeSH Prohlížeč

The rate of chromosome segregation errors that emerge during meiosis I in the mammalian female germ line are known to increase with maternal age; however, little is known about the underlying molecular mechanism. The objective of this study was to analyze meiotic progression of mouse oocytes in relation to maternal age. Using the mouse as a model system, we analyzed the timing of nuclear envelope breakdown and the morphology of the nuclear lamina of oocytes obtained from young (2 months old) and aged females (12 months old). Oocytes obtained from older females display a significantly faster progression through meiosis I compared to the ones obtained from younger females. Furthermore, in oocytes from aged females, lamin A/C structures exhibit rapid phosphorylation and dissociation. Additionally, we also found an increased abundance of MPF components and increased translation of factors controlling translational activity in the oocytes of aged females. In conclusion, the elevated MPF activity observed in aged female oocytes affects precocious meiotic processes that can multifactorially contribute to chromosomal errors in meiosis I.

• Klíčová slova
• MPF, aging, lamin A/C, meiosis, oocyte, translation,
• MeSH
• faktor podporující zrání genetika   metabolismus   MeSH
• fosforylace MeSH
• jaderný obal metabolismus   ultrastruktura   MeSH
• meióza * MeSH
• mezotelin MeSH
• myši MeSH
• oocyty cytologie   metabolismus   MeSH
• posttranslační úpravy proteinů MeSH
• stárnutí genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktor podporující zrání MeSH
• mezotelin MeSH
• Msln protein, mouse MeSH Prohlížeč

The dark web scene has been drawing the attention of law enforcement agencies and researchers alike. To date, most of the published works on the dark web are based on data gained by passive observation. To gain a more contextualized perspective, a study was conducted in which three vendors were selected on the "Dream Market" dark web marketplace, from whom subsequently several new psychoactive substances (NPS) were ordered. All transactions were documented from the initial drug deal solicitation to the final qualitative analysis of all received samples. From the selected vendors, a total of nine NPS samples was obtained, all of which were analyzed by NMR, HRMS, LC-UV, and two also by x-ray diffraction. According to our analyses, four of the five substances offered under already known NPS names contained a different NPS. The selected vendors therefore either did not know about their product, or deliberately deceived the buyers. Furthermore, two of three obtained samples of purportedly novel NPS were identified as already documented substances sold under a different name. However, the third characterized substance sold as "MPF-47700" was a novel, yet uncharacterized, NPS. Finally, we received a single undeclared substance, later identified as 5F-ADB. In addition to chemical analysis of the nine obtained NPS samples, the methodology used also yielded contextual information about the accessibility of NPS on the dark web, the associated purchase process, and the modus operandi of three NPS vendors. Direct participation in dark web marketplaces seems to provide additional layers of information useful for forensic studies.

• Klíčová slova
• Dream Market, MPF-47700, dark web, darknet, new psychoactive substances,
• MeSH
• hmotnostní spektrometrie MeSH
• internet MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• obchodování s drogami * MeSH
• odhalování abúzu drog MeSH
• psychotropní léky analýza   zásobování a distribuce   MeSH
• spektrofotometrie ultrafialová MeSH
• zakázané drogy analýza   zásobování a distribuce   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• psychotropní léky MeSH
• zakázané drogy MeSH

Cell division cycle (Cdc) kinase subunit (CKS) proteins bind cyclin-dependent kinases (CDKs) and play important roles in cell division control and development, though their precise molecular functions are not fully understood. Mammals express two closely related paralogs called CKS1 and CKS2, but only CKS2 is expressed in the germ line, indicating that it is solely responsible for regulating CDK functions in meiosis. Using cks2-/- knockout mice, we show that CKS2 is a crucial regulator of maturation-promoting factor (MPF; CDK1-cyclin A/B) activity in meiosis. cks2-/- oocytes display reduced and delayed MPF activity during meiotic progression, leading to defects in germinal vesicle breakdown (GVBD), anaphase-promoting complex/cyclosome (APC/C) activation, and meiotic spindle assembly. cks2-/- germ cells express significantly reduced levels of the MPF components CDK1 and cyclins A1/B1. Additionally, injection of MPF plus CKS2, but not MPF alone, restored normal GVBD in cks2-/- oocytes, demonstrating that GVBD is driven by a CKS2-dependent function of MPF. Moreover, we generated cks2cks1/cks1 knock-in mice and found that CKS1 can compensate for CKS2 in meiosis in vivo, but homozygous embryos arrested development at the 2- to 5-cell stage. Collectively, our results show that CKS2 is a crucial regulator of MPF functions in meiosis and that its paralog, CKS1, must be excluded from the germ line for proper embryonic development.

• Klíčová slova
• CKS, cyclin-dependent kinases, developmental biology, meiosis,
• MeSH
• embryonální vývoj * MeSH
• faktor podporující zrání metabolismus   MeSH
• genový knockin MeSH
• kinasy CDC2-CDC28 genetika   metabolismus   MeSH
• meióza MeSH
• mezotelin MeSH
• myši knockoutované MeSH
• myši MeSH
• oocyty cytologie   metabolismus   MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• Cks1 protein, mouse MeSH Prohlížeč
• Cks2 protein, mouse MeSH Prohlížeč
• faktor podporující zrání MeSH
• kinasy CDC2-CDC28 MeSH
• mezotelin MeSH
• Msln protein, mouse MeSH Prohlížeč
• proteiny buněčného cyklu MeSH

The role of hydrogen sulfide (H2S) is addressed in Xenopuslaevis oocytes. Three enzymes involved in H2S metabolism, cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase, were detected in prophase I and metaphase II-arrested oocytes and drove an acceleration of oocyte meiosis resumption when inhibited. Moreover, meiosis resumption is associated with a significant decrease in endogenous H2S. On another hand, a dose-dependent inhibition was obtained using the H2S donor, NaHS (1 and 5 mM). NaHS impaired translation. NaHS did not induce the dissociation of the components of the M-phase promoting factor (MPF), cyclin B and Cdk1, nor directly impacted the MPF activity. However, the M-phase entry induced by microinjection of metaphase II MPF-containing cytoplasm was diminished, suggesting upstream components of the MPF auto-amplification loop were sensitive to H2S. Superoxide dismutase and catalase hindered the effects of NaHS, and this sensitivity was partially dependent on the production of reactive oxygen species (ROS). In contrast to other species, no apoptosis was promoted. These results suggest a contribution of H2S signaling in the timing of amphibian oocytes meiosis resumption.

• Klíčová slova
• Xenopus laevis, cell cycle, hydrogen sulfide, meiosis, oocyte,
• MeSH
• apoptóza účinky léků   MeSH
• cyklin B metabolismus   MeSH
• cystathionin-beta-synthasa antagonisté a inhibitory   metabolismus   MeSH
• cystathionin-gama-lyasa antagonisté a inhibitory   metabolismus   MeSH
• cytoplazma metabolismus   MeSH
• faktor podporující zrání metabolismus   MeSH
• fosfatasy cdc25 metabolismus   MeSH
• katalasa metabolismus   MeSH
• meióza účinky léků   MeSH
• metafáze účinky léků   MeSH
• oocyty chemie   enzymologie   metabolismus   MeSH
• profáze meiózy I účinky léků   MeSH
• proteinkinasy metabolismus   MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• proteiny Xenopus metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• sulfan metabolismus   MeSH
• sulfidy metabolismus   farmakologie   MeSH
• sulfurtransferasy antagonisté a inhibitory   metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 3-mercaptopyruvate sulphurtransferase MeSH Prohlížeč
• CDC25C protein, human MeSH Prohlížeč
• CDK1 protein, Xenopus MeSH Prohlížeč
• cyklin B MeSH
• cystathionin-beta-synthasa MeSH
• cystathionin-gama-lyasa MeSH
• faktor podporující zrání MeSH
• fosfatasy cdc25 MeSH
• katalasa MeSH
• proteinkinasy MeSH
• proteiny buněčného cyklu MeSH
• proteiny Xenopus MeSH
• reaktivní formy kyslíku MeSH
• sodium bisulfide MeSH Prohlížeč
• sulfan MeSH
• sulfidy MeSH
• sulfurtransferasy MeSH
• superoxiddismutasa MeSH

In this review, recent data concerning growth and maturation of nonmammalian and mammalian female germ cells are compiled with regard to the increased understanding of somatic cells mitotic cycles, from yeast to human tissues. These data allow us to conclude that growing oocytes of nonvertebrates, lower vertebrates, and mammals resemble somatic cells in the G1 phase of the mitotic cycle in their metabolic and cell cycle behavior. Transcriptional and translational activity of growing oocytes and G1 somatic cells is not compatible with the activation of maturation promoting factor (MPF), with chromatin condensation or with nuclear membrane disintegration. Growing oocytes, even when they are in the dictyate stage of the first meiotic division, promptly inactivate MPF introduced into their cytoplasm by fusion or microinjection, just as do somatic interphase cells. In mammals, the LH surge induces "de novo" RNA and protein synthesis in granulosa cells. This metabolic change in granulosa cells abolishes their inhibitory activity, and meiosis in fully grown oocytes in preovulatory follicles is then resumed. Resumption of meiosis requires an activation of pre MPF molecules within oocytes. This can be achieved either without (mouse, rat, and rabbit) or with (pig, sheep, and cow) an active protein synthesis by the oocytes. The species specificity is probably dependent on the presence or absence of cyclin-like and/or mos-like molecules in fully grown oocytes. Both major events during GVBD, chromatin condensation, and nuclear envelope disintegration require protein phosphorylation. Experimentally, these two phosphorylation activities can be separated one from another. The active MPF molecules are amplified autocatalytically in amphibian and starfish oocytes. However, an increase of MPF activity in mouse and pig oocytes, similarly as in Rana pipiens and sturgeon oocytes, requires an active protein synthesis.

• MeSH
• buněčné jádro metabolismus   MeSH
• buněčný cyklus * MeSH
• cytoplazma metabolismus   MeSH
• lidé MeSH
• meióza MeSH
• mezotelin MeSH
• mitóza MeSH
• oocyty cytologie   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The aim of this study was to test whether vitrification of sterlet Acipenser ruthenus and Russian sturgeon Acipenser gueldenstaedtii ovarian tissue through needle-immersed vitrification (NIV) is an efficient strategy for the preservation of oogonia (OOG) in order to supplement the current conservation efforts for these endangered fish species. Histological analyses of the gonads displayed that the ovaries of both species were immature and contained predominantly OOG and primary oocytes. The germline origin of these cells was verified by localization of the vasa protein through immunocytochemistry. NIV protocol was optimized by testing different equilibration (ES) and vitrification solutions (VS) containing various concentrations of dimethyl sulfoxide (Me2SO), propylene glycol (PG) or methanol (MeOH). In sterlet, the highest average viability (55.7 ± 11.5%) was obtained by using a combination of 1.5 M PG and 1.5 M Me2SO in the ES, and 1.5 M MeOH and 5.5 M Me2SO in the VS. In Russian sturgeon, the highest average viability (49.4 ± 17.1%) was obtained by using a combination of 1.5 M MeOH and 1.5 M Me2SO in the ES, and 3 M PG and 3 M Me2SO in the VS. To test whether vitrified/warmed OOG are functional, we have conducted an intra-specific transplantation assay to verify whether transplanted sterlet OOG will colonize the gonads of recipient fish. Fluorescently labelled cells were detected within recipient gonads at 2 and 3 months post-fertilization (mpf). Colonization rates of vitrified/warmed OOG (70% at 2 mpf and 61% at 3 mpf) were similar to those of fresh OOG (80% at 2 mpf and 70% at 3 mpf). This study has demonstrated that vitrification of ovarian tissue is an effective method for the preservation of OOG, and that the vitrified/warmed cells are functional and are able to colonize recipient gonads after transplantation similarly to the fresh cells. Since the vitrification procedure displayed in this study is simple and does not require complex and expensive laboratory equipment, it can be readily applied in field conditions, and therefore it can be invaluable for the conservation efforts of the critically endangered sturgeon species. However, care needs to be taken that despite the research conducted so far, donor-derived progeny was not yet obtained in sturgeons.

• Klíčová slova
• Acipenseriformes, Cryopreservation, Germ cells, Oogonia, Ovarian stem cells,
• MeSH
• ovarium * MeSH
• ryby MeSH
• vitrifikace * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Mammalian meiotic maturation is regulated by changes in the phosphorylation state of proteins involved in signalling pathways. The regulatory proteins include the family of Src tyrosine kinases. Src family kinases (SFKs) are required for meiotic maturation of mouse oocytes, and it remains to be elucidated whether they play the same role in porcine oocytes. To clarify the role of SFKs in the meiotic maturation of porcine oocytes we used inhibition of SFKs, western blotting and immunolocalisation to determine the presence of SFKs and localisation in the oocytes and assays to determine the activity of maturation-promoting factor (MPF) and mitogen-activated protein kinase (MAPK). Inhibition of SFKs resulted in the disruption of oocyte maturation and led to a decline in MPF and MAPK activity. The fluorescence intensity of SFKs in the cytoplasm and membrane of MI oocytes decreased significantly compared with germinal vesicle oocytes. The highest fluorescence intensity for SFKs was detected on the membrane of MII oocytes. Only weak fluorescence was detected in the perichromosomal area of MI and MII oocytes. These results prove that SFKs play an active role in the meiotic maturation of porcine oocytes by regulating MPF and MAPK activity.

• MeSH
• buněčné jádro metabolismus   MeSH
• faktor podporující zrání metabolismus   MeSH
• meióza fyziologie   MeSH
• mezotelin MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• oocyty růst a vývoj   metabolismus   MeSH
• prasata MeSH
• signální transdukce fyziologie   MeSH
• skupina kinas odvozených od src-genu metabolismus   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktor podporující zrání MeSH
• mezotelin MeSH
• mitogenem aktivované proteinkinasy MeSH
• Msln protein, mouse MeSH Prohlížeč
• skupina kinas odvozených od src-genu MeSH