Cellular growth and the preparation of cells for division between two successive cell divisions is called the cell cycle. The cell cycle is divided into several phases; the length of these particular cell cycle phases is an important characteristic of cell life. The progression of cells through these phases is a highly orchestrated process governed by endogenous and exogenous factors. For the elucidation of the role of these factors, including pathological aspects, various methods have been developed. Among these methods, those focused on the analysis of the duration of distinct cell cycle phases play important role. The main aim of this review is to guide the readers through the basic methods of the determination of cell cycle phases and estimation of their length, with a focus on the effectiveness and reproducibility of the described methods.

• Klíčová slova
• BrdU, DNA labeling, EdU, cell cycle, labeled nucleosides, markers of cell cycle phases, time lapse microscopy,
• MeSH
• bromodeoxyuridin * metabolismus   MeSH
• buněčné dělení MeSH
• buněčný cyklus MeSH
• proliferace buněk MeSH
• reprodukovatelnost výsledků MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• bromodeoxyuridin * MeSH

The incorporation of histone H3 with an acetylated lysine 56 (H3K56ac) into the nucleosome is important for chromatin remodeling and serves as a marker of new nucleosomes during DNA replication and repair in yeast. However, in human cells, the level of H3K56ac is greatly reduced, and its role during the cell cycle is controversial. Our aim was to determine the potential of H3K56ac to regulate cell cycle progression in different human cell lines. A significant increase in the number of H3K56ac foci, but not in H3K56ac protein levels, was observed during the S and G2 phases in cancer cell lines, but was not observed in embryonic stem cell lines. Despite this increase, the H3K56ac signal was not present in late replication chromatin, and H3K56ac protein levels did not decrease after the inhibition of DNA replication. H3K56ac was not tightly associated with the chromatin and was primarily localized to active chromatin regions. Our results support the role of H3K56ac in transcriptionally active chromatin areas but do not confirm H3K56ac as a marker of newly synthetized nucleosomes in DNA replication.

• Klíčová slova
• Cell cycle, Chromatin, DNA replication, H3K56ac, Mammalian cells, Nucleosome,
• MeSH
• buněčný cyklus genetika   fyziologie   MeSH
• chromatin metabolismus   MeSH
• G2 fáze genetika   MeSH
• histony metabolismus   MeSH
• HL-60 buňky MeSH
• hmotnostní spektrometrie MeSH
• lidé MeSH
• nukleozomy metabolismus   MeSH
• replikace DNA genetika   fyziologie   MeSH
• S fáze genetika   MeSH
• Saccharomyces cerevisiae - proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromatin MeSH
• histony MeSH
• nukleozomy MeSH
• Saccharomyces cerevisiae - proteiny MeSH

Hematopoietic stem and progenitor cells (HSPCs) are crucial for lifelong blood cell production. We analyzed the cell cycle and cell production rate in HSPCs in murine hematopoiesis. The labeling of DNA-synthesizing cells by two thymidine analogues, optimized for in-vivo use, enabled determination of the cell cycle flow rate into G2-phase, the duration of S-phase and the average cell cycle time in Sca-1+ and Sca-1- HSPCs. Determination of cells with 2n DNA content labeled in preceding S-phase was then used to establish the cell flow rates in G1-phase. Our measurements revealed a significant difference in how Sca-1+ and Sca-1- myeloid progenitors self-renew and differentiate. Division of the Sca-1+ progenitors led to loss of the Sca-1 marker in about half of newly produced cells, corresponding to asymmetric cell division. Sca-1- cells arising from cell division entered a new round of the cell cycle, corresponding to symmetric self-renewing cell division. The novel data also enabled the estimation of the cell production rates in Sca-1+ and in three subtypes of Sca-1- HSPCs and revealed Sca-1 negative cells as the major amplification stage in the blood cell development.

• Klíčová slova
• Hematopoiesis, blood cell production, cell cycle, mouse, progenitors, stem cells,
• MeSH
• antigeny Ly metabolismus   MeSH
• buněčná diferenciace * MeSH
• buněčná sebeobnova MeSH
• buněčný cyklus * MeSH
• DNA biosyntéza   MeSH
• G2 fáze MeSH
• hematopoetické kmenové buňky cytologie   metabolismus   MeSH
• membránové proteiny metabolismus   MeSH
• myši inbrední C57BL MeSH
• počet buněk MeSH
• proliferace buněk MeSH
• reologie MeSH
• S fáze MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny Ly MeSH
• DNA MeSH
• Ly6a protein, mouse MeSH Prohlížeč
• membránové proteiny MeSH

The structural challenges faced by eukaryotic cells through the cell cycle are key for understanding cell viability and proliferation. We tested the hypothesis that the biosynthesis of structural lipids is linked to the cell cycle. If true, this would suggest that the cell's structure is important for progress through and perhaps even control of the cell cycle. Lipidomics (31P NMR and MS), proteomics (Western immunoblotting) and transcriptomics (RT-qPCR) techniques were used to profile the lipid fraction and characterise aspects of its metabolism at seven stages of the cell cycle of the model eukaryote, Desmodesmus quadricauda. We found considerable, transient increases in the abundance of phosphatidylethanolamine during the G1 phase (+35%, ethanolamine phosphate cytidylyltransferase increased 2·5×) and phosphatidylglycerol (+100%, phosphatidylglycerol synthase increased 22×) over the G1/pre-replication phase boundary. The relative abundance of phosphatidylcholine fell by ~35% during the G1. N-Methyl transferases for the conversion of phosphatidylethanolamine into phosphatidylcholine were not found in the de novo transcriptome profile, though a choline phosphate transferase was found, suggesting that the Kennedy pathway is the principal route for the synthesis of PC. The fatty acid profiles of the four most abundant lipids suggested that these lipids were not generally converted between one another. This study shows for the first time that there are considerable changes in the biosynthesis of the three most abundant phospholipid classes in the normal cell cycle of D. quadricauda, by margins large enough to elicit changes to the physical properties of membranes.

• Klíčová slova
• Cell cycle, Cell division, Cell structure, Desmodesmus quadricauda, Green algae, Lipid composition, Lipid metabolism,
• MeSH
• buněčný cyklus * MeSH
• fosfatidylcholiny metabolismus   biosyntéza   MeSH
• fosfatidylethanolaminy metabolismus   biosyntéza   MeSH
• fosfolipidy * metabolismus   biosyntéza   MeSH
• lipidomika metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfatidylcholiny MeSH
• fosfatidylethanolaminy MeSH
• fosfolipidy * MeSH
• phosphatidylethanolamine MeSH Prohlížeč

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

Multiple fission is a cell cycle variation leading to the production of more than two daughter cells. Here, we used synchronized cultures of the chlorococcal green alga Parachlorella kessleri to study its growth and pattern of cell division under varying light intensities. The time courses of DNA replication, nuclear and cellular division, cell size, total RNA, protein content, dry matter and accumulation of starch were observed at incident light intensities of 110, 250 and 500 µmol photons m-2s-1. Furthermore, we studied the effect of deuterated water on Parachlorella kessleri growth and division, to mimic the effect of stress. We describe a novel multiple fission cell cycle pattern characterized by multiple rounds of DNA replication leading to cell polyploidization. Once completed, multiple nuclear divisions were performed with each of them, immediately followed by protoplast fission, terminated by the formation of daughter cells. The multiple fission cell cycle was represented by several consecutive doublings of growth parameters, each leading to the start of a reproductive sequence. The number of growth doublings increased with increasing light intensity and led to division into more daughter cells. This study establishes the baseline for cell cycle research at the molecular level as well as for potential biotechnological applications, particularly directed synthesis of (deuterated) starch and/or neutral lipids as carbon and energy reserves.

• Klíčová slova
• Parachlorella kessleri, cell cycle pattern, deuterated lipid, deuterated starch, deuterium, energy reserves, growth processes, light intensity, reproduction events,
• MeSH
• buněčné kultury * MeSH
• buněčný cyklus * MeSH
• Chlorophyta růst a vývoj   MeSH
• světlo * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem 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

A synchronous population of cells is one of the prerequisites for studying cell cycle processes such as DNA replication, nuclear and cellular division. Green algae dividing by multiple fission represent a unique single cell system enabling the preparation of highly synchronous cultures by application of a light-dark regime similar to what they experience in nature. This chapter provides detailed protocols for synchronization of different algal species by alternating light-dark cycles; all critical points are discussed extensively. Moreover, detailed information on basic analysis of cell cycle progression in such cultures is presented, including analyses of nuclear, cellular, and chloroplast divisions. Modifications of basic protocols that enable changes in cell cycle progression are also suggested so that nuclear or chloroplast divisions can be followed separately.

• Klíčová slova
• Cell division, Chloroplast division, DNA replication, Green algae, Growth, Illumination regime, Multiple fission cell cycle, Nuclear division, Synchronization,
• MeSH
• barvení a značení metody   MeSH
• buněčné dělení MeSH
• buněčné kultury metody   MeSH
• buněčný cyklus MeSH
• Chlamydomonas reinhardtii cytologie   genetika   růst a vývoj   MeSH
• Chlorophyta cytologie   genetika   růst a vývoj   MeSH
• chloroplasty genetika   MeSH
• DNA rostlinná genetika   MeSH
• fotoperioda * MeSH
• frakcionace buněk metody   MeSH
• replikace DNA MeSH
• světlo MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA rostlinná 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

The ovarian granulosa cells (GCs) that form the structure of follicle undergo substantial modification during the various stages of human folliculogenesis. These modifications include morphological changes, accompanied by differential expression of genes, encoding proteins which are mainly involved in cell growth, proliferation and differentiation. Recent data bring a new insight into the aspects of GCs' stem-like specificity and plasticity, enabling their prolonged proliferation and differentiation into other cell types. This manuscript focuses attention on emerging alterations during GC cell cycle - a series of biochemical and biophysical changes within the cell. Human GCs were collected from follicles of women set to undergo intracytoplasmic sperm injection procedure, as a part of remnant follicular fluid. The cells were primarily cultured for 30 days. Throughout this time, we observed the prominent change in cell morphology from epithelial-like to fibroblast-like, suggesting differentiation to other cell types. Additionally, at days 1, 7, 15 and 30, the RNA was isolated for molecular assays. Using Affymetrix® Human Genome U219 Array, we found 2579 human transcripts that were differentially expressed in GCs. From these genes, we extracted 582 Gene Ontology Biological Process (GO BP) Terms and 45 KEGG pathways, among which we investigated transcripts belonging to four GO BPs associated with cell proliferation: "cell cycle phase transition", "G1/S phase transition", G2/M phase transition" and "cell cycle checkpoint". Microarray results were validated by RT-qPCR. Increased expression of all the genes studied indicated that increase in GC proliferation during long-term in vitro culture is orchestrated by the up-regulation of genes related to cell cycle control. Furthermore, observed changes in cell morphology may be regulated by a presented set of genes, leading to the induction of pathways specific for stemness plasticity and transdifferentiation in vitro.

• Klíčová slova
• cell cycle, human ovarian granulosa cells, in vitro, progression,
• MeSH
• buněčný cyklus * MeSH
• folikulární buňky cytologie   MeSH
• lidé MeSH
• ovariální folikul cytologie   MeSH
• transkriptom * MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH