Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Influence of M-phase chromatin on the anisotropy of microtubule asters.
Dogterom M
,
Félix MA
,
Guet CC
,
Leibler S
.
???displayArticle.abstract???
In many eukaryotic cells going through M-phase, a bipolar spindle is formed by microtubules nucleated from centrosomes. These microtubules, in addition to being "captured" by kinetochores, may be stabilized by chromatin in two different ways: short-range stabilization effects may affect microtubules in close contact with the chromatin, while long-range stabilization effects may "guide" microtubule growth towards the chromatin (e.g., by introducing a diffusive gradient of an enzymatic activity that affects microtubule assembly). Here, we use both meiotic and mitotic extracts from Xenopus laevis eggs to study microtubule aster formation and microtubule dynamics in the presence of chromatin. In "low-speed" meiotic extracts, in the presence of salmon sperm chromatin, we find that short-range stabilization effects lead to a strong anisotropy of the microtubule asters. Analysis of the dynamic parameters of microtubule growth show that this anisotropy arises from a decrease in the catastrophe frequency, an increase in the rescue frequency and a decrease in the growth velocity. In this system we also find evidence for long-range "guidance" effects, which lead to a weak anisotropy of the asters. Statistically relevant results on these long-range effects are obtained in "high-speed" mitotic extracts in the presence of artificially constructed chromatin stripes. We find that aster anisotropy is biased in the direction of the chromatin and that the catastrophe frequency is reduced in its vicinity. In this system we also find a surprising dependence of the catastrophe and the rescue frequencies on the length of microtubules nucleated from centrosomes: the catastrophe frequency increase and the rescue frequency decreases with microtubule length.
Belmont,
Real-time visualization of cell cycle-dependent changes in microtubule dynamics in cytoplasmic extracts.
1990, Pubmed,
Xenbase
Belmont,
Real-time visualization of cell cycle-dependent changes in microtubule dynamics in cytoplasmic extracts.
1990,
Pubmed
,
Xenbase
Chrétien,
Structure of growing microtubule ends: two-dimensional sheets close into tubes at variable rates.
1995,
Pubmed
Church,
Micromanipulated bivalents can trigger mini-spindle formation in Drosophila melanogaster spermatocyte cytoplasm.
1986,
Pubmed
Dogterom,
Diffusion and formation of microtubule asters: physical processes versus biochemical regulation.
1995,
Pubmed
,
Xenbase
Felix,
A post-ribosomal supernatant from activated Xenopus eggs that displays post-translationally regulated oscillation of its cdc2+ mitotic kinase activity.
1989,
Pubmed
,
Xenbase
Félix,
Centrosome assembly in vitro: role of gamma-tubulin recruitment in Xenopus sperm aster formation.
1994,
Pubmed
,
Xenbase
Fernandez,
Protein phosphatase type 1 in mammalian cell mitosis: chromosomal localization and involvement in mitotic exit.
1992,
Pubmed
Gard,
Microtubule assembly in cytoplasmic extracts of Xenopus oocytes and eggs.
1987,
Pubmed
,
Xenbase
Glotzer,
Cyclin is degraded by the ubiquitin pathway.
1991,
Pubmed
,
Xenbase
Hirano,
Cell cycle control of higher-order chromatin assembly around naked DNA in vitro.
1991,
Pubmed
,
Xenbase
Holy,
Dynamic instability of microtubules as an efficient way to search in space.
1994,
Pubmed
Hyman,
Preparation of modified tubulins.
1991,
Pubmed
Karsenti,
Mitotic spindle morphogenesis in animal cells.
1991,
Pubmed
Karsenti,
Respective roles of centrosomes and chromatin in the conversion of microtubule arrays from interphase to metaphase.
1984,
Pubmed
,
Xenbase
Kirschner,
Beyond self-assembly: from microtubules to morphogenesis.
1986,
Pubmed
Lohka,
Formation in vitro of sperm pronuclei and mitotic chromosomes induced by amphibian ooplasmic components.
1983,
Pubmed
,
Xenbase
McIntosh,
Mitosis.
1989,
Pubmed
Mitchison,
Isolation of mammalian centrosomes.
1986,
Pubmed
Mitchison,
Dynamic instability of microtubule growth.
,
Pubmed
Mitchison,
Microtubule assembly nucleated by isolated centrosomes.
,
Pubmed
Murray,
Cell cycle extracts.
1991,
Pubmed
Odde,
Kinetics of microtubule catastrophe assessed by probabilistic analysis.
1995,
Pubmed
Pickett-Heaps,
Rethinking mitosis.
1982,
Pubmed
Sawin,
Mitotic spindle assembly by two different pathways in vitro.
1991,
Pubmed
,
Xenbase
Sorger,
Factors required for the binding of reassembled yeast kinetochores to microtubules in vitro.
1994,
Pubmed
Steffen,
Aster-free spindle poles in insect spermatocytes: evidence for chromosome-induced spindle formation?
1986,
Pubmed
Theurkauf,
Meiotic spindle assembly in Drosophila females: behavior of nonexchange chromosomes and the effects of mutations in the nod kinesin-like protein.
1992,
Pubmed
Verde,
Control of microtubule dynamics and length by cyclin A- and cyclin B-dependent kinases in Xenopus egg extracts.
1992,
Pubmed
,
Xenbase
Verde,
Regulation of microtubule dynamics by cdc2 protein kinase in cell-free extracts of Xenopus eggs.
1990,
Pubmed
,
Xenbase
Zhang,
The impact of chromosomes and centrosomes on spindle assembly as observed in living cells.
1995,
Pubmed
Zimmermann,
DNA stretching on functionalized gold surfaces.
1994,
Pubmed
