Mechanisms of spindle assembly and size control

G, Guilloux; Gibeaux, Romain

doi:10.1111/boc.202000065

Cited by 9 publications

(3 citation statements)

References 150 publications

(181 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mitotic spindle assembly largely relies on the ability of microtubules to continuously and stochastically oscillate between phases of polymerization and depolymerization, a process called dynamic instability [ 28 ]. The size of the mitotic spindle is directly linked to the properties and the size of each of its individual components, including microtubules, centrosomes and chromosomes (reviewed in [ 29 ]). Analyzing how the size and assembly timing of these components is controlled during cell division is thus key to understanding the principles of spatial and temporal scaling of the spindle.…”

Section: Mitotic Spindle Assemblymentioning

confidence: 99%

Spatial and Temporal Scaling of Microtubules and Mitotic Spindles

Lacroix

Dumont

2022

Cells

View full text Add to dashboard Cite

During cell division, the mitotic spindle, a macromolecular structure primarily comprised of microtubules, drives chromosome alignment and partitioning between daughter cells. Mitotic spindles can sense cellular dimensions in order to adapt their length and mass to cell size. This scaling capacity is particularly remarkable during early embryo cleavage when cells divide rapidly in the absence of cell growth, thus leading to a reduction of cell volume at each division. Although mitotic spindle size scaling can occur over an order of magnitude in early embryos, in many species the duration of mitosis is relatively short, constant throughout early development and independent of cell size. Therefore, a key challenge for cells during embryo cleavage is not only to assemble a spindle of proper size, but also to do it in an appropriate time window which is compatible with embryo development. How spatial and temporal scaling of the mitotic spindle is achieved and coordinated with the duration of mitosis remains elusive. In this review, we will focus on the mechanisms that support mitotic spindle spatial and temporal scaling over a wide range of cell sizes and cellular contexts. We will present current models and propose alternative mechanisms allowing cells to spatially and temporally coordinate microtubule and mitotic spindle assembly.

show abstract

Section: Mitotic Spindle Assemblymentioning

confidence: 99%

Spatial and Temporal Scaling of Microtubules and Mitotic Spindles

Lacroix

Dumont

2022

Cells

View full text Add to dashboard Cite

show abstract

“…Numerous models describe how wild-type cell divisions occur. However, because of the complexity resulting from both numbers and families of molecular actors involved, it is often required to focus on one part of cell division [Sönnichsen et al, 2005, Prosser and Pelletier, 2017, Guilloux and Gibeaux, 2020, Cai et al, 2018]. In particular, the correct partitioning of the chromosomes critically depends on the metaphasic spindle.…”

Section: Introductionmentioning

confidence: 99%

Only three principal components account for inter-embryo variability of the spindle length over time

Cunff

Chesneau

Pastezeur

et al. 2023

Preprint

View full text Add to dashboard Cite

How does inter-individual variability emerge? When measuring a large number of features per experiment/individual, this question becomes non-trivial. One challenge lies in choosing features to recapitulate high-dimension data. In this paper, we focus on spindle elongation phenotype to highlight how a data-driven approach can help. We showed that only three typical elongation patterns could describe spindle elongation in C.elegansone-cell embryo. We called them archetypes. These archetypes were automatically extracted from the experimental data using principal component analysis (PCA) rather than defined a priori. They accounted for more than 85% of inter-individual variability in a dataset of more than 1600 experiments across more than 100 different experimental conditions (RNAi, mutants, changes in temperature, etc.). The two first archetypes were consistent with standard measures in the field, namely the average spindle length and the spindle elongation rate both in late metaphase and anaphase. However, our archetypes were not strictly corresponding to these manually-set features. The third archetype, accounting for 6% of the variance, was novel and corresponded to a transient spindle shortening in late metaphase. We propose that it is part of spindle elongation dynamics in all conditions. It is reminiscent of the elongation pattern observed upon defects in kinetochore function. Notably, the same archetypes emerged when analysing non-treated embryos only at various temperatures. Interestingly, because these archetypes were not specific to metaphase or anaphase, it implied that spindle elongation around anaphase-onset is sufficient to predict its late anaphase length. We validated this idea using a machine-learning approach. Despite the apparent variability in phenotypes across the various conditions, inter-individual differences between embryos depleted from one cell division-related protein have the same underlying nature as inter-individual differences naturally arising between wild-type embryos. The same conclusion holds when analysing embryos dividing at various temperatures. We thus propose that beyond the apparent complexity of the spindle, only three independent mechanisms account for spindle elongation, and contribute differently in the various conditions, meanwhile, no mechanism is specific to any condition.

show abstract

“…Although Xenopus egg extract systems have been instrumental in the study of mitotic spindle assembly, and more recently in facilitating interspecies comparisons to better understand mechanisms of spindle size regulation (reviewed in [ 19 ]), they have also been broadly used to investigate microtubules at all stages of the cell cycle. Such studies include investigation of interphase aster assembly and dynamics [ 20 , 21 , 22 ], as well as the aster’s role in cell-like compartmentalization [ 23 ] and the positioning of both organelles [ 24 ] and the cytokinesis machinery [ 21 ].…”

Section: Introductionmentioning

confidence: 99%

The Cytoskeleton and Its Roles in Self-Organization Phenomena: Insights from Xenopus Egg Extracts

Geisterfer

Gatlin

et al. 2021

Cells

Self Cite

View full text Add to dashboard Cite

Self-organization of and by the cytoskeleton is central to the biology of the cell. Since their introduction in the early 1980s, cytoplasmic extracts derived from the eggs of the African clawed-frog, Xenopus laevis, have flourished as a major experimental system to study the various facets of cytoskeleton-dependent self-organization. Over the years, the many investigations that have used these extracts uniquely benefited from their simplified cell cycle, large experimental volumes, biochemical tractability and cell-free nature. Here, we review the contributions of egg extracts to our understanding of the cytoplasmic aspects of self-organization by the microtubule and the actomyosin cytoskeletons as well as the importance of cytoskeletal filaments in organizing nuclear structure and function.

show abstract

Mechanisms of spindle assembly and size control

Cited by 9 publications

References 150 publications

Spatial and Temporal Scaling of Microtubules and Mitotic Spindles

Spatial and Temporal Scaling of Microtubules and Mitotic Spindles

Only three principal components account for inter-embryo variability of the spindle length over time

The Cytoskeleton and Its Roles in Self-Organization Phenomena: Insights from Xenopus Egg Extracts

Contact Info

Product

Resources

About