Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.

• MeSH
• buněčná diferenciace MeSH
• buněčné kultury MeSH
• buněčný cyklus fyziologie   MeSH
• embryonální kmenové buňky cytologie   fyziologie   MeSH
• kontrolní body buněčného cyklu fyziologie   MeSH
• lidé MeSH
• pluripotentní kmenové buňky cytologie   fyziologie   MeSH
• proteiny buněčného cyklu metabolismus   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• proteiny buněčného cyklu MeSH

Green algae dividing by multiple fission comprise unrelated genera but are connected by one common feature: under optimal growth conditions, they can divide into more than two daughter cells. The number of daughter cells, also known as the division number, is relatively stable for most species and usually ranges from 4 to 16. The number of daughter cells is dictated by growth rate and is modulated by light and temperature. Green algae dividing by multiple fission can thus be used to study coordination of growth and progression of the cell cycle. Algal cultures can be synchronized naturally by alternating light/dark periods so that growth occurs in the light and DNA replication(s) and nuclear and cellular division(s) occur in the dark; synchrony in such cultures is almost 100% and can be maintained indefinitely. Moreover, the pattern of cell-cycle progression can be easily altered by differing growth conditions, allowing for detailed studies of coordination between individual cell-cycle events. Since the 1950s, green algae dividing by multiple fission have been studied as a unique model for cell-cycle regulation. Future sequencing of algal genomes will provide additional, high precision tools for physiological, taxonomic, structural, and molecular studies in these organisms.

• Klíčová slova
• Cell division, DNA replication, cell size, green algae, growth, light, multiple fission cell cycle, nuclear division, temperature.,
• MeSH
• buněčný cyklus * MeSH
• Chlorophyta cytologie   genetika   MeSH
• replikace DNA MeSH
• světlo MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The onset of an early development is, in mammals, characterized by profound changes of multiple aspects of cellular morphology and behavior. These are including, but not limited to, fertilization and the merging of parental genomes with a subsequent transition from the meiotic into the mitotic cycle, followed by global changes of chromatin epigenetic modifications, a gradual decrease in cell size and the initiation of gene expression from the newly formed embryonic genome. Some of these important, and sometimes also dramatic, changes are executed within the period during which the gene transcription is globally silenced or not progressed, and the regulation of most cellular activities, including those mentioned above, relies on controlled translation. It is known that the blastomeres within an early embryo are prone to chromosome segregation errors, which might, when affecting a significant proportion of a cell within the embryo, compromise its further development. In this review, we discuss how the absence of transcription affects the transition from the oocyte to the embryo and what impact global transcriptional silencing might have on the basic cell cycle and chromosome segregation controlling mechanisms.

• Klíčová slova
• cell cycle, embryo, oocyte, transcriptional repression, translation,
• MeSH
• buněčný cyklus genetika   MeSH
• chromatin genetika   MeSH
• embryo savčí fyziologie   MeSH
• embryonální vývoj genetika   MeSH
• genetická transkripce genetika   MeSH
• lidé MeSH
• segregace chromozomů genetika   MeSH
• umlčování genů fyziologie   MeSH
• vývojová regulace genové exprese genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• chromatin MeSH

Objectives: To advance our knowledge of disease mechanisms and therapeutic options, understanding cell cycle regulation is critical. Recent research has highlighted the importance of reactive oxygen species (ROS) in cell cycle regulation. Although excessive ROS levels can lead to age-related pathologies, ROS also play an essential role in normal cellular functions. Many cell cycle regulatory proteins are affected by their redox status, but the precise mechanisms and conditions under which ROS promote or inhibit cell proliferation are not fully understood.Methods: This review presents data from the scientific literature and publicly available databases on changes in redox state during the cell cycle and their effects on key regulatory proteins.Results: We identified redox-sensitive targets within the cell cycle machinery and analysed different effects of ROS (type, concentration, duration of exposure) on cell cycle phases. For example, moderate levels of ROS can promote cell proliferation by activating signalling pathways involved in cell cycle progression, whereas excessive ROS levels can induce DNA damage and trigger cell cycle arrest or cell death.Discussion: Our findings encourage future research focused on identifying redox-sensitive targets in the cell cycle machinery, potentially leading to new treatments for diseases with dysregulated cell proliferation.

• Klíčová slova
• Cell cycle, cell cycle signaling, oxidative stress, proliferation, reactive oxygen species, redox state, redox-sensitive targets,
• MeSH
• buněčný cyklus * MeSH
• lidé MeSH
• oxidace-redukce * MeSH
• poškození DNA MeSH
• proliferace buněk MeSH
• reaktivní formy kyslíku * metabolismus   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• reaktivní formy kyslíku * MeSH

The literature demonstrating tight regulation of the Escherichia coli cell cycle is reviewed. Recent evidence is presented indicating that the normal rod cell shape can be abandoned, allowing growth as a coccus, either by increasing the amount of the division proteins FtsZ, FtsA and FtsQ, or by increasing the pool of the nucleotide ppGpp. It is argued that ppGpp may be a cell cycle signal in E. coli.

• MeSH
• buněčný cyklus fyziologie   MeSH
• Escherichia coli cytologie   růst a vývoj   MeSH
• guanosintetrafosfát metabolismus   MeSH
• modely genetické MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• guanosintetrafosfát MeSH

Embryonic stem cells seem to have the intriguing capacity to divide indefinitely while retaining their pluripotency. This self-renewal is accomplished by specialized mechanisms of cell-cycle control. In the last few years, several studies have provided evidence for a direct link between cell-cycle regulation and cell-fate decisions in stem cells. In this review, we discuss the peculiarities of embryonic stem cell-cycle control mechanisms, implicate their involvement in cell-fate decisions, and distinguish centrosomes as important players in the self-renewal versus differentiation roulette.

• MeSH
• buněčná diferenciace MeSH
• buněčné dělení fyziologie   MeSH
• buněčný cyklus fyziologie   MeSH
• centrozom metabolismus   MeSH
• embryonální kmenové buňky cytologie   fyziologie   MeSH
• lidé MeSH
• poškození DNA MeSH
• proliferace buněk MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The cell shape of Trypanosoma brucei is influenced by flagellum-to-cell-body attachment through a specialised structure - the flagellum attachment zone (FAZ). T. brucei exhibits numerous morphological forms during its life cycle and, at each stage, the FAZ length varies. We have analysed FLAM3, a large protein that localises to the FAZ region within the old and new flagellum. Ablation of FLAM3 expression causes a reduction in FAZ length; however, this has remarkably different consequences in the tsetse procyclic form versus the mammalian bloodstream form. In procyclic form cells FLAM3 RNAi results in the transition to an epimastigote-like shape, whereas in bloodstream form cells a severe cytokinesis defect associated with flagellum detachment is observed. Moreover, we demonstrate that the amount of FLAM3 and its localisation is dependent on ClpGM6 expression and vice versa. This evidence demonstrates that FAZ is a key regulator of trypanosome shape, with experimental perturbations being life cycle form dependent. An evolutionary cell biology explanation suggests that these differences are a reflection of the division process, the cytoskeleton and intrinsic structural plasticity of particular life cycle forms.

• Klíčová slova
• Flagellum attachment zone, Morphogenesis, Trypanosomes,
• MeSH
• cilie genetika   metabolismus   MeSH
• cytokineze genetika   MeSH
• cytoskelet genetika   metabolismus   MeSH
• flagella genetika   metabolismus   MeSH
• mikrotubuly genetika   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• stadia vývoje genetika   MeSH
• Trypanosoma brucei brucei genetika   růst a vývoj   MeSH
• tvar buňky genetika   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protozoální proteiny MeSH

Temperature is one of the key factors affecting growth and division of algal cells. High temperature inhibits the cell cycle in Chlamydomonas reinhardtii. At 39 °C, nuclear and cellular divisions in synchronized cultures were blocked completely, while DNA replication was partly affected. In contrast, growth (cell volume, dry matter, total protein, and RNA) remained unaffected, and starch accumulated at very high levels. The cell cycle arrest could be removed by transfer to 30 °C, but a full recovery occurred only in cultures cultivated up to 14 h at 39 °C. Thereafter, individual cell cycle processes began to be affected in sequence; daughter cell release, cell division, and DNA replication. Cell cycle arrest was accompanied by high mitotic cyclindependent kinase activity that decreased after completion of nuclear and cellular division following transfer to 30 °C. Cell cycle arrest was, therefore, not caused by a lack of cyclin-dependent kinase activity but rather a blockage in downstream processes.

• Klíčová slova
• Chlamydomonas reinhardtii, DNA replication, cell cycle arrest, cell size, cyclin-dependent kinase, starch accumulation, supraoptimal temperature, synchronized cultures,
• MeSH
• bílkoviny řas metabolismus   MeSH
• buněčné kultury metody   MeSH
• Chlamydomonas reinhardtii cytologie   fyziologie   MeSH
• cyklin-dependentní kinasy metabolismus   MeSH
• down regulace MeSH
• fyziologický stres MeSH
• kontrolní body buněčného cyklu * MeSH
• regulace genové exprese u rostlin MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bílkoviny řas MeSH
• cyklin-dependentní kinasy MeSH

A mathematical model of the cell cycle regulation in S. cerevisiae is proposed. The model is based on the assumption of the G1----S phase transition control mediated by two signals. One of them is correlated with the cellular energy level--its messenger could be cAMP; the second one depends on the change of the cellular growth rate (reaching the critical size) and remains hypothetical.

• MeSH
• AMP cyklický fyziologie   MeSH
• biologické modely * MeSH
• buněčný cyklus * MeSH
• matematika MeSH
• počítačová simulace MeSH
• Saccharomyces cerevisiae růst a vývoj   MeSH
• systémy druhého messengeru MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• AMP cyklický MeSH

The objective of this study was to describe co-expression correlations of cell cycle regulatory genes in multiple myeloma (MM) and plasma cell leukemia (PCL). Our results highlight the presence of dynamic equilibrium between co-expression of activator and inhibitor gene sets. Moreover inhibitor set is more sensitive to the activator changes, not vice versa. We have shown that CDKN2A expression is associated with short-term survival in newly diagnosed MM patients (survival was 30.3 ± 3.9 months for 'low' expressed and 7.5 ± 5.6 months for 'high' expressed group, p<0.0001). Moreover low-expression CDKN2A group showed time-to-progression benefit in newly diagnosed patients (remission was 20.8 ± 3.6 months for 'low' and 8.4 ± 2.7 months for 'high' expressed group, p<0.0001) as well as in whole studied cohort of MM patients (remission was 20.8 ± 2.8 months for 'low' and 9.8 ± 1.1 months for 'high' expressed group, p<0.0001). The overexpression of inhibitors can be explained as a compensatory reaction to growing "oncogenic stress".

• Klíčová slova
• Cell cycle genes, Multiple myeloma, Overall survival, Plasma cell leukemia, Time-to-progression,
• MeSH
• analýza přežití MeSH
• buněčný cyklus genetika   MeSH
• časové faktory MeSH
• CDC geny * MeSH
• HeLa buňky MeSH
• inhibitor p16 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mnohočetný myelom diagnóza   genetika   MeSH
• nádorové buňky kultivované MeSH
• plazmocelulární leukemie diagnóza   genetika   MeSH
• prognóza MeSH
• progrese nemoci MeSH
• regulace genové exprese u nádorů MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibitor p16 cyklin-dependentní kinasy MeSH