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Mitotic spindle assembly by two different pathways in vitro.
Sawin KE
,
Mitchison TJ
.
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We have used Xenopus egg extracts to study spindle morphogenesis in a cell-free system and have identified two pathways of spindle assembly in vitro using methods of fluorescent analogue cytochemistry. When demembranated sperm nuclei are added to egg extracts arrested in a mitotic state, individual nuclei direct the assembly of polarized microtubule arrays, which we term half-spindles; half-spindles then fuse pairwise to form bipolar spindles. In contrast, when sperm nuclei are added to extracts that are induced to enter interphase and arrested in the following mitosis, a single spermnucleus can direct the assembly of a complete spindle. We find that microtubule arrays in vitro are strongly biased towards chromatin, but this does not depend on specific kinetochore-microtubule interactions. Indeed, although we have identified morphological and probably functional kinetochores in spindles assembled in vitro, kinetochores appear not to play an obligate role in the establishment of stable, bipolar microtubule arrays in either assembly pathway. Features of the two pathways suggest that spindle assembly involves a hierarchy of selective microtubule stabilization, involving both chromatin-microtubule interactions and antiparallel microtubule-microtubule interactions, and that fundamental molecular interactions are probably the same in both pathways. This in vitro reconstitution system should be useful for identifying the molecules regulating the generation of asymmetric microtubule arrays and for understanding spindle morphogenesis in general.
BRIGGS,
An investigation of the capacity for cleavage and differentiation in Rana pipiens eggs lacking "functional" chromosomes.
1951, Pubmed
BRIGGS,
An investigation of the capacity for cleavage and differentiation in Rana pipiens eggs lacking "functional" chromosomes.
1951,
Pubmed
Bajer,
Functional autonomy of monopolar spindle and evidence for oscillatory movement in mitosis.
1982,
Pubmed
Belmont,
Real-time visualization of cell cycle-dependent changes in microtubule dynamics in cytoplasmic extracts.
1990,
Pubmed
,
Xenbase
Blow,
Nuclei act as independent and integrated units of replication in a Xenopus cell-free DNA replication system.
1987,
Pubmed
,
Xenbase
Brenner,
Kinetochore structure, duplication, and distribution in mammalian cells: analysis by human autoantibodies from scleroderma patients.
1981,
Pubmed
Brinkley,
Movement and segregation of kinetochores experimentally detached from mammalian chromosomes.
1988,
Pubmed
Church,
Micromanipulated bivalents can trigger mini-spindle formation in Drosophila melanogaster spermatocyte cytoplasm.
1986,
Pubmed
Dinsmore,
Calcium and calmodulin-dependent phosphorylation of a 62 kd protein induces microtubule depolymerization in sea urchin mitotic apparatuses.
1988,
Pubmed
Enos,
Mutation of a gene that encodes a kinesin-like protein blocks nuclear division in A. nidulans.
1990,
Pubmed
Evans,
Influence of the centrosome on the structure of nucleated microtubules.
1985,
Pubmed
Gard,
Centrosome duplication continues in cycloheximide-treated Xenopus blastulae in the absence of a detectable cell cycle.
1990,
Pubmed
,
Xenbase
Gard,
Microtubule assembly in cytoplasmic extracts of Xenopus oocytes and eggs.
1987,
Pubmed
,
Xenbase
Gorbsky,
Microtubule dynamics and chromosome motion visualized in living anaphase cells.
1988,
Pubmed
Gurdon,
Injected nuclei in frog oocytes: fate, enlargement, and chromatin dispersal.
1976,
Pubmed
,
Xenbase
Hutchison,
The control of DNA replication in a cell-free extract that recapitulates a basic cell cycle in vitro.
1988,
Pubmed
,
Xenbase
Ikegami,
Aphidicolin prevents mitotic cell division by interfering with the activity of DNA polymerase-alpha.
1978,
Pubmed
Karsenti,
Interconversion of metaphase and interphase microtubule arrays, as studied by the injection of centrosomes and nuclei into Xenopus eggs.
1984,
Pubmed
,
Xenbase
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
Kristofferson,
Direct observation of steady-state microtubule dynamics.
1986,
Pubmed
Lohka,
Formation in vitro of sperm pronuclei and mitotic chromosomes induced by amphibian ooplasmic components.
1983,
Pubmed
,
Xenbase
Lohka,
The germinal vesicle material required for sperm pronuclear formation is located in the soluble fraction of egg cytoplasm.
1983,
Pubmed
,
Xenbase
Lohka,
Induction of nuclear envelope breakdown, chromosome condensation, and spindle formation in cell-free extracts.
1985,
Pubmed
,
Xenbase
Lohka,
Purification of maturation-promoting factor, an intracellular regulator of early mitotic events.
1988,
Pubmed
,
Xenbase
Masuda,
The mechanism of anaphase spindle elongation: uncoupling of tubulin incorporation and microtubule sliding during in vitro spindle reactivation.
1988,
Pubmed
Masui,
Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes.
1971,
Pubmed
Mazia,
Cooperation of kinetochores and pole in the establishment of monopolar mitotic apparatus.
1981,
Pubmed
Mazia,
Centrosomes and mitotic poles.
1984,
Pubmed
Mazia,
The chromosome cycle and the centrosome cycle in the mitotic cycle.
1987,
Pubmed
McIntosh,
Mitosis.
1989,
Pubmed
McIntosh,
Three-dimensional structure of the central mitotic spindle of Diatoma vulgare.
1979,
Pubmed
Meluh,
KAR3, a kinesin-related gene required for yeast nuclear fusion.
1990,
Pubmed
Mitchison,
Dynamic instability of microtubule growth.
,
Pubmed
Mitchison,
Properties of the kinetochore in vitro. II. Microtubule capture and ATP-dependent translocation.
1985,
Pubmed
Mitchison,
Sites of microtubule assembly and disassembly in the mitotic spindle.
1986,
Pubmed
Mitchison,
Microtubule dynamics and kinetochore function in mitosis.
1988,
Pubmed
Murray,
Cyclin synthesis drives the early embryonic cell cycle.
1989,
Pubmed
,
Xenbase
Murray,
The role of cyclin synthesis and degradation in the control of maturation promoting factor activity.
1989,
Pubmed
,
Xenbase
Murray,
Dominoes and clocks: the union of two views of the cell cycle.
1989,
Pubmed
Nagano,
Achromosomal cleavage of fertilized starfish eggs in the presence of aphidicolin.
1981,
Pubmed
Newport,
Disassembly of the nucleus in mitotic extracts: membrane vesicularization, lamin disassembly, and chromosome condensation are independent processes.
1987,
Pubmed
,
Xenbase
Nicklas,
Mitosis.
1971,
Pubmed
Nicklas,
The total length of spindle microtubules depends on the number of chromosomes present.
1985,
Pubmed
Nicklas,
The motor for poleward chromosome movement in anaphase is in or near the kinetochore.
1989,
Pubmed
Picard,
Germinal vesicle components are not required for the cell-cycle oscillator of the early starfish embryo.
1988,
Pubmed
RAPPAPORT,
Experiments concerning the cleavage stimulus in sand dollar eggs.
1961,
Pubmed
Raff,
Centrosomes, and not nuclei, initiate pole cell formation in Drosophila embryos.
1989,
Pubmed
Rieder,
The formation, structure, and composition of the mammalian kinetochore and kinetochore fiber.
1982,
Pubmed
Rieder,
Oscillatory movements of monooriented chromosomes and their position relative to the spindle pole result from the ejection properties of the aster and half-spindle.
1986,
Pubmed
Sagata,
The c-mos proto-oncogene product is a cytostatic factor responsible for meiotic arrest in vertebrate eggs.
1989,
Pubmed
,
Xenbase
Salmon,
Calcium-labile mitotic spindles isolated from sea urchin eggs (Lytechinus variegatus).
1980,
Pubmed
Salmon,
Spindle microtubule dynamics in sea urchin embryos: analysis using a fluorescein-labeled tubulin and measurements of fluorescence redistribution after laser photobleaching.
1984,
Pubmed
Sawin,
Poleward microtubule flux mitotic spindles assembled in vitro.
1991,
Pubmed
,
Xenbase
Saxton,
Tubulin dynamics in cultured mammalian cells.
1984,
Pubmed
Saxton,
Interzone microtubule behavior in late anaphase and telophase spindles.
1987,
Pubmed
Schulze,
Microtubule dynamics in interphase cells.
1986,
Pubmed
Shpetner,
Identification of dynamin, a novel mechanochemical enzyme that mediates interactions between microtubules.
1989,
Pubmed
Sluder,
Control mechanisms of the cell cycle: role of the spatial arrangement of spindle components in the timing of mitotic events.
1983,
Pubmed
Sluder,
Centriole number and the reproductive capacity of spindle poles.
1985,
Pubmed
Sluder,
Experimental separation of pronuclei in fertilized sea urchin eggs: chromosomes do not organize a spindle in the absence of centrosomes.
1985,
Pubmed
Sluder,
The reproduction of centrosomes: nuclear versus cytoplasmic controls.
1986,
Pubmed
Verde,
Regulation of microtubule dynamics by cdc2 protein kinase in cell-free extracts of Xenopus eggs.
1990,
Pubmed
,
Xenbase
Ward,
Identification of cell cycle-regulated phosphorylation sites on nuclear lamin C.
1990,
Pubmed
,
Xenbase
Watanabe,
Specific proteolysis of the c-mos proto-oncogene product by calpain on fertilization of Xenopus eggs.
1989,
Pubmed
,
Xenbase
Wordeman,
Reactivation of spindle elongation in vitro is correlated with the phosphorylation of a 205 kd spindle-associated protein.
1987,
Pubmed