The nuclear lamina represents a multifunctional platform involved in such diverse yet interconnected processes as spatial organization of the genome, maintenance of mechanical stability of the nucleus, regulation of transcription and replication. Most of lamina activities are exerted through tethering of lamina-associated chromatin domains (LADs) to the nuclear periphery. Yet, the lamina is a dynamic structure demonstrating considerable expansion during the cell cycle to accommodate increased number of LADs formed during DNA replication. We analyzed dynamics of nuclear growth during interphase and changes in lamina structure as a function of cell cycle progression. The nuclear lamina demonstrates steady growth from G1 till G2, while quantitative analysis of lamina meshwork by super-resolution microscopy revealed that microdomain organization of the lamina is maintained, with lamin A and lamin B microdomain periodicity and interdomain gap sizes unchanged. FRAP analysis, in contrast, demonstrated differences in lamin A and B1 exchange rates; the latter showing higher recovery rate in S-phase cells. In order to further analyze the mechanism of lamina growth in interphase, we generated a lamina-free nuclear envelope in living interphase cells by reversible hypotonic shock. The nuclear envelope in nuclear buds formed after such a treatment initially lacked lamins, and analysis of lamina formation revealed striking difference in lamin A and B1 assembly: lamin A reassembled within 30 min post-treatment, whereas lamin B1 did not incorporate into the newly formed lamina at all. We suggest that in somatic cells lamin B1 meshwork growth is coordinated with replication of LADs, and lamin A meshwork assembly seems to be chromatin-independent process.

• Klíčová slova
• Cell cycle, DNA replication, Interphase, Microdomains, Nuclear lamina, Nucleus,
• MeSH
• Cricetulus MeSH
• interfáze * MeSH
• jaderná lamina chemie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• myši MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Condensins are best known for their role in shaping chromosomes. Other functions such as organizing interphase chromatin and transcriptional control have been reported in yeasts and animals, but little is known about their function in plants. To elucidate the specific composition of condensin complexes and the expression of CAP-D2 (condensin I) and CAP-D3 (condensin II), we performed biochemical analyses in Arabidopsis. The role of CAP-D3 in interphase chromatin organization and function was evaluated using cytogenetic and transcriptome analysis in cap-d3 T-DNA insertion mutants. CAP-D2 and CAP-D3 are highly expressed in mitotically active tissues. In silico and pull-down experiments indicate that both CAP-D proteins interact with the other condensin I and II subunits. In cap-d3 mutants, an association of heterochromatic sequences occurs, but the nuclear size and the general histone and DNA methylation patterns remain unchanged. Also, CAP-D3 influences the expression of genes affecting the response to water, chemicals, and stress. The expression and composition of the condensin complexes in Arabidopsis are similar to those in other higher eukaryotes. We propose a model for the CAP-D3 function during interphase in which CAP-D3 localizes in euchromatin loops to stiffen them and consequently separates centromeric regions and 45S rDNA repeats.

• Klíčová slova
• Arabidopsis thaliana, SMC proteins, chromatin organization, chromosomes, condensin, interphase nuclei,
• MeSH
• adenosintrifosfatasy genetika   MeSH
• Arabidopsis * genetika   MeSH
• chromatin * MeSH
• DNA vazebné proteiny MeSH
• interfáze MeSH
• multiproteinové komplexy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfatasy MeSH
• chromatin * MeSH
• condensin complexes MeSH Prohlížeč
• DNA vazebné proteiny MeSH
• multiproteinové komplexy MeSH

The arrangement of chromatin within interphase nuclei seems to be caused by topological constraints and related to gene expression depending on tissue and developmental stage. In yeast and animals it was found that homologous and heterologous chromatin association are required to realize faithful expression and DNA repair. To test whether such associations are present in plants we analyzed Arabidopsis thaliana interphase nuclei by FISH using probes from different chromosomes. We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances. The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns. Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus. Nevertheless, chromatin movement enables a flexible spatial genome arrangement in plant nuclei.

• Klíčová slova
• Arabidopsis, BAC, FISH, chromatin association, chromosome territory, expression, interphase nucleus, transcription,
• Publikační typ
• časopisecké články MeSH

The meadowfoam family (Limnanthaceae) is one of the smallest and genomically underexplored families of the Brassicales. The Limnanthaceae harbor about seven species in the genus Limnanthes (meadowfoam) and Floerkea proserpinacoides (false mermaidweed), all native to North America. Because all Limnanthes and Floerkea species have only five chromosome pairs, i.e., a chromosome number rare in Brassicales and shared with Arabidopsis thaliana (Arabidopsis), we examined the Limnanthaceae genomes as a potential model system. Using low-coverage whole-genome sequencing data, we reexamined phylogenetic relationships and characterized the repeatomes of Limnanthaceae genomes. Phylogenies based on complete chloroplast and 35S rDNA sequences corroborated the sister relationship between Floerkea and Limnanthes and two major clades in the latter genus. The genome size of Limnanthaceae species ranges from 1.5 to 2.1 Gb, apparently due to the large increase in DNA repeats, which constitute 60-70% of their genomes. Repeatomes are dominated by long terminal repeat retrotransposons, while tandem repeats represent only less than 0.5% of the genomes. The average chromosome size in Limnanthaceae species (340-420 Mb) is more than 10 times larger than in Arabidopsis (32 Mb). A three-dimensional fluorescence in situ hybridization analysis demonstrated that the five chromosome pairs in interphase nuclei of Limnanthes species adopt the Rabl-like configuration.

• Klíčová slova
• Brassicales, DNA repeats, Limnanthes, Rabl, chromosomes, interphase, meadowfoam, repeatome,
• MeSH
• Arabidopsis * genetika   MeSH
• chromozomy MeSH
• fylogeneze MeSH
• hybridizace in situ fluorescenční MeSH
• interfáze MeSH
• Magnoliopsida * genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Arabidopsis thaliana has become a major plant research model, where interphase nuclear organization exhibits unique features, including nucleolus-associated telomere clustering. The chromocenter (CC)-loop model, or rosette-like configuration, describes intranuclear chromatin organization in Arabidopsis as megabase-long loops anchored in, and emanating from, peripherally positioned CCs, with those containing telomeres associating with the nucleolus. To investigate whether the CC-loop organization is universal across the mustard family (crucifers), the nuclear distributions of centromeres, telomeres and nucleoli were analyzed by fluorescence in situ hybridization in seven diploid species (2n = 10-16) representing major crucifer clades with an up to 26-fold variation in genome size (160-4260 Mb). Nucleolus-associated telomere clustering was confirmed in Arabidopsis (157 Mb) and was newly identified as the major nuclear phenotype in other species with a small genome (215-381 Mb). In large-genome species (2611-4264 Mb), centromeres and telomeres adopted a Rabl-like configuration or dispersed distribution in the nuclear interior; telomeres only rarely associated with the nucleolus. In Arabis cypria (381 Mb) and Bunias orientalis (2611 Mb), tissue-specific patterns deviating from the major nuclear phenotypes were observed in anther and stem tissues, respectively. The rosette-like configuration, including nucleolus-associated telomere clustering in small-genome species from different infrafamiliar clades, suggests that genomic properties rather than phylogenetic position determine the interphase nuclear organization. Our data suggest that nuclear genome size, average chromosome size and degree of longitudinal chromosome compartmentalization affect interphase chromosome organization in crucifer genomes.

• Klíčová slova
• Arabidopsis thaliana, Crucifereae, Rabl, centromere, chromocenter-loop model, interphase, nucleolus, telomere,
• MeSH
• Arabidopsis genetika   MeSH
• Arabis genetika   MeSH
• Brassicaceae genetika   MeSH
• buněčné jadérko genetika   MeSH
• centromera genetika   MeSH
• chromatin genetika   MeSH
• délka genomu MeSH
• fylogeneze MeSH
• genom rostlinný * MeSH
• heterochromatin genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• interfáze MeSH
• ribozomální DNA genetika   MeSH
• telomery genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromatin MeSH
• heterochromatin MeSH
• ribozomální DNA MeSH

Despite much recent progress, our understanding of the principles of plant genome organization and its dynamics in three-dimensional space of interphase nuclei remains surprisingly limited. Notably, it is not clear how these processes could be affected by the size of a plant's nuclear genome. In this study, DNA replication timing and interphase chromosome positioning were analyzed in seven Poaceae species that differ in their genome size. To provide a comprehensive picture, a suite of advanced, complementary methods was used: labeling of newly replicated DNA by ethynyl-2'-deoxyuridine, isolation of nuclei at particular cell cycle phases by flow cytometric sorting, three-dimensional immunofluorescence in situ hybridization, and confocal microscopy. Our results revealed conserved dynamics of DNA replication in all species, and a similar replication timing order for telomeres and centromeres, as well as for euchromatin and heterochromatin regions, irrespective of genome size. Moreover, stable chromosome positioning was observed while transitioning through different stages of interphase. These findings expand upon earlier studies in suggesting that a more complex interplay exists between genome size, organization of repetitive DNA sequences along chromosomes, and higher order chromatin structure and its maintenance in interphase, albeit controlled by currently unknown factors.

• Klíčová slova
• Poaceae, DNA replication, EdU labeling, Rabl configuration, S phase, flow cytometry, three-dimensional fluorescence in situ hybridization (3D-FISH),
• MeSH
• buněčné jádro * genetika   MeSH
• centromera genetika   MeSH
• genom rostlinný MeSH
• interfáze MeSH
• replikace DNA MeSH
• umístění chromozomů * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Although graphite materials with desirable comprehensive properties dominate the anode market of commercial lithium-ion batteries (LIBs), their low capacity during fast charging precludes further commercialization. In the present work, natural graphite (G) is reported not only to suffer from low capacity during fast charging, but also from charge failure after many charging cycles. Using different characterization techniques, severe graphite exfoliation, and continuously increasing solid electrolyte interphase (SEI) are demonstrated as reasons for the failure of G samples. An ultrathin artificial SEI is proposed, addressing these problems effectively and ensuring extremely stable operation of the graphite anode, with a capacity retention of ≈97.5% after 400 cycles at 1 C. Such an artificial SEI modification strategy provides a universal approach to tailoring and designing better anode materials for next-generation LIBs with high energy densities.

• Klíčová slova
• artificial solid electrolyte interphase (SEI), graphite anodes, graphite exfoliation,
• Publikační typ
• časopisecké články MeSH

Genetic information in the cell nucleus controls organismal development and responses to the environment, and finally ensures its own transmission to the next generations. To achieve so many different tasks, the genetic information is associated with structural and regulatory proteins, which orchestrate nuclear functions in time and space. Furthermore, plant life strategies require chromatin plasticity to allow a rapid adaptation to abiotic and biotic stresses. Here, we summarize current knowledge on the organization of plant chromatin and dynamics of chromosomes during interphase and mitotic and meiotic cell divisions for model and crop plants differing as to genome size, ploidy, and amount of genomic resources available. The existing data indicate that chromatin changes accompany most (if not all) cellular processes and that there are both shared and unique themes in the chromatin structure and global chromosome dynamics among species. Ongoing efforts to understand the molecular mechanisms involved in chromatin organization and remodeling have, together with the latest genome editing tools, potential to unlock crop genomes for innovative breeding strategies and improvements of various traits.

• Klíčová slova
• Arabidopsis, chromatin, chromosome, crops, epigenetics, meiosis, mitosis, plant breeding, plant development,
• MeSH
• buněčné dělení MeSH
• chromatin * genetika   MeSH
• chromozomy MeSH
• interfáze MeSH
• šlechtění rostlin * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• chromatin * MeSH

To study 3D nuclear distributions of epigenetic histone modifications such as H3(K9) acetylation, H3(K4) dimethylation, H3(K9) dimethylation, and H3(K27) trimethylation, and of histone methyltransferase Suv39H1, we used advanced image analysis methods, combined with Nipkow disk confocal microscopy. Total fluorescence intensity and distributions of fluorescently labelled proteins were analyzed in formaldehyde-fixed interphase nuclei. Our data showed reduced fluorescent signals of H3(K9) acetylation and H3(K4) dimethylation (di-me) at the nuclear periphery, while di-meH3(K9) was also abundant in chromatin regions closely associated with the nuclear envelope. Little overlapping (intermingling) was observed for di-meH3(K4) and H3(K27) trimethylation (tri-me), and for di-meH3(K9) and Suv39H1. The histone modifications studied were absent in the nucleolar compartment with the exception of H3(K9) dimethylation that was closely associated with perinucleolar regions which are formed by centromeres of acrocentric chromosomes. Using immunocytochemistry, no di-meH3(K4) but only dense di-meH3(K9) was found for the human acrocentric chromosomes 14 and 22. The active X chromosome was observed to be partially acetylated, while the inactive X was more condensed, located in a very peripheral part of the interphase nuclei, and lacked H3(K9) acetylation. Our results confirmed specific interphase patterns of histone modifications within the interphase nuclei as well as within their chromosome territories.

• MeSH
• acetylace MeSH
• algoritmy MeSH
• buněčné jádro metabolismus   MeSH
• centromera ultrastruktura   MeSH
• fibroblasty metabolismus   MeSH
• histony metabolismus   MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie MeSH
• interfáze fyziologie   MeSH
• lidé MeSH
• lidské chromozomy X genetika   ultrastruktura   MeSH
• lidské chromozomy, pár 14 genetika   ultrastruktura   MeSH
• lidské chromozomy, pár 22 genetika   ultrastruktura   MeSH
• metylace MeSH
• počítačové zpracování obrazu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• histony MeSH

Natural graphite, with its lower production cost, higher capacity, and superior electrical conductivity than artificial graphite, currently accounts for approximately 40% of the global lithium-ion battery anode market. However, the inadequate compatibility of natural graphite with commercial carbonate ester electrolytes leads to irreversible capacity loss, reduce coulombic efficiency, and rapid capacity decline during cycling. Applying an oxygen-deficient titanium dioxide (TiO2-x) protective layer to natural graphite anodes has been noted as a successful method for improving their structural integrity and cycling stability; however, the fragile solid-electrolyte interphase (SEI) limits their fast-charging capability. In this study, nitrogen atoms are strategically incorporated into the TiO2-x surface structures, creating a lychee-like primary interphase that regulated the interfacial electrochemistry and facilitated the development of a LiF-dominated SEI. The robust LiF-dominated SEI, as examined through ex situ X-ray photoelectron spectroscopy analysis and kinetic evaluations, successfully mitigates interfacial side reactions and enhances bulk charge transfer. Consequently, the modified natural graphite anodes exhibit improved capacities at higher current densities, delivering a stable reversible capacity of 388.9 mAh g-1 after 200 cycles at a rate of 5 C.

• Klíčová slova
• LiF‐dominated SEI, fast‐charging anode, lychee‐like primary interphase, natural graphite,
• Publikační typ
• časopisecké články MeSH