Chromatin Compaction Follows a Power Law Scaling with Cell Size from Interphase Through Mitosis DOI Creative Commons
Petra Stockinger, Anna Oddone, Melike Lakadamyali

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Дек. 8, 2024

Abstract Coordination of mitotic chromosome compaction with cell size is crucial for proper genome segregation during mitosis. During development, DNA content remains constant but evolves, necessitating a mechanism that scales size. In this study, we examined chromatin in the developing Drosophila nervous system by analyzing large neuronal stem cells and their smaller progeny, ganglion mother cells. Using super-resolution 3D Stochastic Optical Reconstruction Microscopy quantitative time-lapse fluorescence microscopy, observed nanoscale density interphase nuclear volume according to power law. This scaling relationship disrupted inhibiting histone deacetylase activity, indicating molecular cues rather than mechanical constraints primarily regulate compaction. Notably, law dependency maintained into mitosis exponent decreases, suggesting phase separation events We propose relative depends on behaviour volume, an emergent property linear polymers undergoing solvent. Statement Significance Understanding how changes essential understanding mechanisms ensuring accurate division. combine Voronoi tessellation analysis image processing methods based intensity spectrum live confocal images measure different sizes. work reveals follows from through mitosis, fundamental principle underlying across show regulated cues, such as conserved potential providing new insights biophysical processes govern organization. broadens our biology will have implications size-dependent dynamics other organisms.

Язык: Английский

The chromosome folding problem and how cells solve it DOI Creative Commons
Job Dekker, Leonid A. Mirny

Cell, Год журнала: 2024, Номер 187(23), С. 6424 - 6450

Опубликована: Ноя. 1, 2024

Every cell must solve the problem of how to fold its genome. We describe folded state chromosomes is result combined activity multiple conserved mechanisms. Homotypic affinity-driven interactions lead spatial partitioning active and inactive loci. Molecular motors through loop extrusion. Topological features such as supercoiling entanglements contribute chromosome folding dynamics, tethering loci sub-nuclear structures adds additional constraints. Dramatically diverse conformations observed throughout cycle across tree life can be explained differential regulation implementation these basic propose that first functions are mediate genome replication, compaction, segregation mechanisms have subsequently been co-opted for other roles, including long-range gene regulation, in different conditions, types, species.

Язык: Английский

Процитировано

10
Mitotic chromosomes scale to nuclear-cytoplasmic ratio and cell size in Xenopus DOI Creative Commons
Coral Y. Zhou,

Bastiaan Dekker,

Ziyuan Liu

и другие.

eLife, Год журнала: 2023, Номер 12

Опубликована: Апрель 25, 2023

During the rapid and reductive cleavage divisions of early embryogenesis, subcellular structures such as nucleus mitotic spindle scale to decreasing cell size. Mitotic chromosomes also decrease in size during development, presumably coordinately with spindles, but underlying mechanisms are unclear. Here we combine vivo vitro approaches using eggs embryos from frog Xenopus laevis show that chromosome scaling is mechanistically distinct other forms scaling. We found continuously cell, spindle, nuclear vivo. However, unlike for spindles nuclei, cannot be reset by cytoplasmic factors earlier developmental stages. In vitro, increasing nuclear-cytoplasmic (N/C) ratio sufficient recapitulate scaling, not or through differential loading maternal interphase. An additional pathway involving importin α scales surface area/volume (SA/V) metaphase. Finally, single-chromosome immunofluorescence Hi-C data suggest shrink embryogenesis decreased recruitment condensin I, resulting major rearrangements DNA loop architecture accommodate same amount on a shorter axis. Together, our findings demonstrate how set spatially temporally cues embryo.

Язык: Английский

Процитировано

8
The nuclear-cytoplasmic ratio controls the cell cycle period in compartmentalized frog egg extract DOI Creative Commons
Liliana Piñeros, Nikita Frolov, Daniel Ruiz-Reynés

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Июль 29, 2024

Each proliferating cell replicates its DNA and internal components before distributing this material evenly to daughters. Although the regulation of cyclin-dependent kinases (Cdks) that dictate orderly cycle progression is well characterized, how subcellular localization machinery contributes timing not understood. We investigated influence nucleus by reconstituting oscillations in droplets frog egg extract absence or presence a nuclear compartment monitoring dynamics time-lapse microscopy. found time increased nuclei, which grew larger with each cycle. The correlation between increasing volume longer period was maintained across extracts nuclei from various Xenopus species persisted upon inhibition replication transcription. However, import kinase Wee1 impacted relationship nuclear-cytoplasmic ratio period. These experimental findings were reproduced computational model incorporating oscillations, compart-mentalization, periodic envelope breakdown reformation. Altogether, our results support major role setting pace provide an explanation for increase length observed at midblastula transition when cells become smaller increases.

Язык: Английский

Процитировано

2
Mitotic chromosomes harbor cell type and species-specific structural features within a universal looping architecture DOI Creative Commons
Marlies E. Oomen, A. Nicole Fox, Inma González

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Дек. 9, 2023

Abstract The architecture of mammalian mitotic chromosomes is considered to be universal across species and cell types. However, some studies suggest that features might type or specific. We previously reported CTCF binding in human differentiated lines lost mitosis, whereas mouse embryonic stem cells (mESC) display prominent at a subset sites mitosis. Here, we perform parallel footprint ATAC-seq data analyses mESCs somatic further explore these differences. then investigate roles mitotically bound (bookmarked) prometaphase chromosome organization by Hi-C. do not find any remaining interphase structures such as TADs loops bookmarked mESCs. This suggests loop extruders condensin I II are blocked CTCF, thus does alter folding. Lastly, compare Hi-C generated this study with publicly available from chicken lines. specific differences; however, difference between species. average genomic size much smaller (200-350 kb), compared (500-750 kb) (1-2 mb). Interestingly, correlated the length q-arm species, finding confirm microscopy measurements compaction. dimensions can modulated through control sizes condensins facilitate species-appropriate shortening arms.

Язык: Английский

Процитировано

4
Single-molecule diffusivity quantification in Xenopus egg extracts elucidates physicochemical properties of the cytoplasm DOI Creative Commons
Alexander A. Choi, Coral Y. Zhou,

Ayana Tabo

и другие.

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(50)

Опубликована: Дек. 5, 2024

The living cell creates a unique internal molecular environment that is challenging to characterize. By combining single-molecule displacement/diffusivity mapping (SM d M) with physiologically active extracts prepared from Xenopus laevis eggs, we sought elucidate properties of the cytoplasm. Quantification diffusion coefficients 15 diverse proteins in extract showed that, compared water, negatively charged diffused ~50% slower, while positively was reduced by ~80 90%. Adding increasing concentrations salt progressively alleviated suppressed observed for proteins, signifying electrostatic interactions within predominately macromolecular environment. To investigate contribution RNA, an abundant, component cytoplasm, were treated ribonuclease, which resulted low diffusivity domains indicative aggregation, likely due liberation RNA-binding such as ribosomal since this effect could be mimicked adding polypeptides. Interestingly, under typical conditions inhibit actin polymerization, different sizes similar suppression consistent our separately measured 2.22-fold higher viscosity over water. Restoring or enhancing polymerization larger recapitulating behaviors cells. Together, these results indicate crowded are defined overwhelmingly containing cytoskeletal networks.

Язык: Английский

Процитировано

1
Single-molecule diffusivity quantification inXenopusegg extracts elucidates physicochemical properties of the cytoplasm DOI Open Access
Alexander A. Choi, Coral Y. Zhou,

Ayana Tabo

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Авг. 26, 2024

The living cell creates a unique internal molecular environment that is challenging to characterize. By combining single-molecule displacement/diffusivity mapping (SM

Язык: Английский

Процитировано

0
Palmitoylated Importin α Regulates Mitotic Spindle Orientation Through Interaction with NuMA DOI Creative Commons
Patrick James Sutton, Natalie Mosqueda, Christopher Brownlee

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Окт. 25, 2024

Abstract Regulation of cell division orientation is a fundamental process critical to differentiation and tissue homeostasis. Microtubules emanating from the mitotic spindle pole bind conserved complex proteins at cortex which orients ultimately plane. Control particular importance in developing tissues, such as brain. Misorientation thus subsequent plane misalignment can contribute improper segregation fate determinants neuroblasts, leading rare neurological disorder known microcephaly. We demonstrate that nuclear transport protein importin α, when palmitoylated, plays role through localizing factors, NuMA, cortex. also observe craniofacial developmental defects Xenopus laevis α palmitoylation abrogated, including smaller head brains, hallmark misorientation These findings characterize not only for orientation, but broader has significance many cellular processes.

Язык: Английский

Процитировано

0
Chromatin Compaction Follows a Power Law Scaling with Cell Size from Interphase Through Mitosis DOI Creative Commons
Petra Stockinger, Anna Oddone, Melike Lakadamyali

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Дек. 8, 2024

Abstract Coordination of mitotic chromosome compaction with cell size is crucial for proper genome segregation during mitosis. During development, DNA content remains constant but evolves, necessitating a mechanism that scales size. In this study, we examined chromatin in the developing Drosophila nervous system by analyzing large neuronal stem cells and their smaller progeny, ganglion mother cells. Using super-resolution 3D Stochastic Optical Reconstruction Microscopy quantitative time-lapse fluorescence microscopy, observed nanoscale density interphase nuclear volume according to power law. This scaling relationship disrupted inhibiting histone deacetylase activity, indicating molecular cues rather than mechanical constraints primarily regulate compaction. Notably, law dependency maintained into mitosis exponent decreases, suggesting phase separation events We propose relative depends on behaviour volume, an emergent property linear polymers undergoing solvent. Statement Significance Understanding how changes essential understanding mechanisms ensuring accurate division. combine Voronoi tessellation analysis image processing methods based intensity spectrum live confocal images measure different sizes. work reveals follows from through mitosis, fundamental principle underlying across show regulated cues, such as conserved potential providing new insights biophysical processes govern organization. broadens our biology will have implications size-dependent dynamics other organisms.

Язык: Английский

Процитировано

0