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Poleward kinetochore fiber movement occurs during both metaphase and anaphase-A in newt lung cell mitosis

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Abstract

Microtubules in the mitotic spindles of newt lung cells were marked using local photoactivation of fluorescence. The movement of marked segments on kinetochore fibers was tracked by digital fluorescence microscopy in metaphase and anaphase and compared to the rate of chromosome movement. In metaphase, kinetochore oscillations toward and away from the poles were coupled to kinetochore fiber shortening and growth. Marked zones on the kinetochore microtubules, meanwhile, moved slowly polewards at a rate of approximately 0.5 micron/min, which identifies a slow polewards movement, or "flux," of kinetochore microtubules accompanied by depolymerization at the pole, as previously found in PtK2 cells (Mitchison, 1989b). Marks were never seen moving away from the pole, indicating that growth of the kinetochore microtubules occurs only at their kinetochore ends. In anaphase, marked zones on kinetochore microtubules also moved polewards, though at a rate slower than overall kinetochore-to-pole movement. Early in anaphase-A, microtubule depolymerization at kinetochores accounted on average for 75% of the rate of chromosome-to-pole movement, and depolymerization at the pole accounted for 25%. When chromosome-to-pole movement slowed in late anaphase, the contribution of depolymerization at the kinetochores lessened, and flux became the dominant component in some cells. Over the whole course of anaphase-A, depolymerization at kinetochores accounted on average for 63% of kinetochore fiber shortening, and flux for 37%. In some anaphase cells up to 45% of shortening resulted from the action of flux. We conclude that kinetochore microtubules change length predominantly through polymerization and depolymerization at the kinetochores during both metaphase and anaphase as the kinetochores move away from and towards the poles. Depolymerization, though not polymerization, also occurs at the pole during metaphase and anaphase, so that flux contributes to polewards chromosome movements throughout mitosis. Poleward force production for chromosome movements is thus likely to be generated by at least two distinct molecular mechanisms

Topics: Articles
Publisher: The Rockefeller University Press
OAI identifier: oai:pubmedcentral.nih.gov:2289668
Provided by: PubMed Central

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Citations

  1. (1986). Analysis of the treadmilling model during metaphase of mitosis using fluorescence redistribution after photobleaching.
  2. (1989). Biotin-tubulin incorporates into kinetochore fiber microtubules during early but not late anaphase.
  3. (1992). Buffer conditions and nontubulin factors critically affect the microtubule dynamic instability of sea urchin egg tubulin. Cell Motil. and Cytoskeleton.
  4. (1967). Cell motility by labile association of molecules. The nature of mitotic spindle fibres and their role in chromosome movement.
  5. (1966). Characterization of the mitotic traction system, and evidence that birefringent spindle fibers neither produce nor transmit force for chromosome movement. Chromosoma (BerL).
  6. (1991). Chromosome fiber dynamics and congression oscillations
  7. (1991). Chromosome motion during attachment to the vertebrate spindle: initial saltatory-like behavior of chromosomes and quantitative analysis of force production by nascent kinetochore fibers.
  8. (1990). Cytoplasmic dynein is localized to kinetochores during mitosis.
  9. (1991). Direct experimental evidence for the existence, structural basis and function of astral forces during anaphase B in vitro.
  10. (1982). Dynamics of spindle microtubule organization: kinetochore fiber microtubules of plant endosperm.
  11. (1991). Feedback control of mitosis in budding yeast.
  12. (1992). Kinetochore microtubules in PtK2 cells.
  13. (1991). Kinetochore microtubules shorten by loss of subunits at the kinetochores of prometaphase chromosomes.
  14. (1990). Kinetochores are transported polewards along a single astral microtubule during chromosome attachment to the spindle in newt lung cells.
  15. (1990). Kinetochores capture astral microtubules during chromosome attachment to the mitotic spindle: direct visualization in live newt cells.
  16. (1965). Local reduction of spindle birefringence in living Nephrotoma suturalis (Loew) spermatocytes induced by ultraviolet microbeam irradiation.
  17. (1990). Localization of cytoplasmic dynein to mitotic spindles and kinetochores.
  18. (1983). Measurements of the force produced by the mitotic spindle in anaphase.
  19. (1983). Meiosis and early cleavage in Drosophila Melanogaster eggs: Effects of the claret-non-disjunctional mutation.
  20. (1992). Microinjection of biotin tubulin into anaphase cells induces transient elongation of kinetochore microtubules and reversal of chromosome-to-pole motion.
  21. (1988). Micromanipulation studies on the mitotic apparatus in sand dollar eggs. Cell Motil. and Cytoskeleton.
  22. (1987). Microtubule assembly in cytoplasmic extracts of Xenopus oocytes and eggs.
  23. (1991). Microtubule depolymerization promotes particle and chromosome movement in vitro.
  24. (1988). Microtubule dynamics and chromosome motion visualized in living anaphase cells.
  25. (1989). Microtubule dynamics and chromosome movement. In Mitosis: Molecules and Mechanisms.
  26. (1988). Microtubule dynamics and kinetochore function in mitosis.
  27. (1988). Microtubule dynamics in the chromosome fiber: Analysis by fluorescence and high resolution polarization microscopy. Celt Motit. and Cytoskeleton.
  28. (1989). Microtubule dynamics investigated by microinjection of Paramecium axonemal tubulin: lack of nucleation but proximal assembly of microtubules at the kinetochore during prometaphase.
  29. (1991). Microtubule dynamics, mechanism, regulation and function.
  30. (1989). Microtubules of the kinetochore fiber turn over in metaphase but not in anaphase.
  31. (1989). Mitosis: basic concepts.
  32. (1991). Mitosis: towards a molecular understanding of chromosome behavior.
  33. (1991). Mitotic motors.
  34. (1991). Motor proteins in cell division.
  35. (1990). Newt lung epithelial cells: cultivation, use, and advantages for biomedical research.
  36. (1991). Pole-to-chromosome movements induced at metaphase: sites of microtubule disassembly.
  37. (1990). Poleward force on the kinetochore at metaphase depends on the number of kinetochore microtubules.
  38. (1991). Poleward microtubule flux in spindles assembled in vitro.
  39. (1988). Polewards chromosome movement driven by microtubule depolymerization in vitro.
  40. (1989). Polewards microtubule flux in the mitotic spindle: evidence from photoactivation of fluorescence.
  41. (1991). Preparation of modified tubulins.
  42. (1985). Properties of the kinetochore in vitro. 2. Microtubule capture and ATP dependant translocation.
  43. (1984). Rapid rate of tubulin dissociation from microtubules in the mitotic spindle in vivo measured by blocking polymerization with colchicine.
  44. (1987). Redistribution of fluorescentty labeled tubulin in the mitotic apparatus of sand dollar Mitchison and Salmon Kinetochore Microtubule Dynamics 581 eggs and the effects of taxol.
  45. (1982). Rethinking mitosis.
  46. (1991). S. cerevisiea genes required for cell cycle arrest in response to loss of microtubule function.
  47. (1992). Self-organization of polymer-motor systems in the cytoskeleton.
  48. (1986). Sites of microtubule assembly and disassembly in the mitotic spindle.
  49. (1984). Spindle microtubule dynamics in sea urchin embryos. Analysis using fluorescence-labeled tubulin and measurements of fluorescence redistribution after laser photobleaching.
  50. (1992). Spindle morphogenesis in animal cells.
  51. (1990). Stability of microtubule attachment to metaphase kinetochores in PtK 1 cells.
  52. (1990). The Drosophila claret segregation protein is a minus-end directed motor molecule.
  53. (1982). The formation, structure, and composition of the mammalian kinetochore and kinetochore fiber.
  54. (1990). The kinesin like ned protein is a minus end directed microtubule motor.
  55. (1989). The mechanism of anaphase spindle elongation.
  56. (1989). The motor for poleward chromosome movement in anaphase is in or near the kinetochore.
  57. (1982). Traction force on a kinetochore at metaphase acts as a linear function of kinetochore fiber length.
  58. (1984). Tubulin dynamics in cultured mammalian ceils.
  59. (1991). Two different microtubule-based motor activities with opposite polarities in kinetochores.
  60. (1990). UV microbeam irradiations of the mitotic spindle II: spindle fiber dynamics and force production.

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