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. 1981 Mar 1;88(3):543–553. doi: 10.1083/jcb.88.3.543

Chromosome behavior after laser microirradiation of a single kinetochore in mitotic PtK2 cells

PMCID: PMC2112755  PMID: 7194343

Abstract

The role of the kinetochore in chromosome movement was studied by 532- nm wavelength laser microirradiation of mitotic PtK2 cells. When the kinetochore of a single chromatid is irradiated at mitotic prometaphase or metaphase, the whole chromosome moves towards the pole to which the unirradiated kinetochore is oriented, while the remaining chromosomes congregate on the metaphase plate. The chromatids of the irradiated chromosome remain attached to one another until anaphase, at which time they separate by a distance of 1 or 2 micrometers and remain parallel to each other, not undergoing any poleward separation. Electron microscopy shows that irradiated chromatids exhibit either no recognizable kinetochore structure or a typical inactive kinetochore in which the tri-layer structure is present but has no microtubules associated with it. Graphical analysis of the movement of the irradiated chromosome shows that the chromosome moves to the pole rapidly with a velocity of approximately 3 micrometers/min. If the chromosome is close to one pole at irradiation, and the kinetochore oriented towards that pole is irradiated, the chromosome moves across the spindle to the opposite pole. The chromosome is slowed down as it traverses the equatorial region, but the velocity in both half-spindles is approximately the same as the anaphase velocity of a single chromatid. Thus a single kinetochore moves twice the normal mass of chromatin (two chromatids) at the same velocity with which it moves a single chromatid, showing that the velocity with which a kinetochore moves is independent, within limits, of the mass associated with it.

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Selected References

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  1. BAJER A. CINE-MICROGRAPHIC STUDIES ON DICENTRIC CHROMOSOMES. Chromosoma. 1964 Dec 10;15:630–651. doi: 10.1007/BF00319996. [DOI] [PubMed] [Google Scholar]
  2. BAJER A., MOLE-BAJER J. UV microbeam irradiation of chromosomes during mitosis in endosperm. Exp Cell Res. 1961 Nov;25:251–267. doi: 10.1016/0014-4827(61)90277-4. [DOI] [PubMed] [Google Scholar]
  3. Berns M. W., Olson R. S., Rounds D. E. In vitro production of chromosomal lesions with an argon laser microbeam. Nature. 1969 Jan 4;221(5175):74–75. doi: 10.1038/221074a0. [DOI] [PubMed] [Google Scholar]
  4. Berns M. W. Partial cell irradiation with a tunable organic dye laser. Nature. 1972 Dec 22;240(5382):483–485. doi: 10.1038/240483a0. [DOI] [PubMed] [Google Scholar]
  5. Brenner S. L., Liaw L. H., Berns M. W. Laser microirradiation of kinetochores in mitotic PtK2 cells: chromatid separation and micronucleus formation. Cell Biophys. 1980 Jun;2(2):139–152. doi: 10.1007/BF02795840. [DOI] [PubMed] [Google Scholar]
  6. Carlson J G. Some Effects of X-Radiation on the Neuroblast Chromosomes of the Grasshopper, Chortophaga Viridifasciata. Genetics. 1938 Nov;23(6):596–609. doi: 10.1093/genetics/23.6.596. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gould R. R., Borisy G. G. Quantitative initiation of microtubule assembly by chromosomes from Chinese hamster ovary cells. Exp Cell Res. 1978 May;113(2):369–374. doi: 10.1016/0014-4827(78)90377-4. [DOI] [PubMed] [Google Scholar]
  8. MOLE-BAJER J. Cine-micrographic analysis of C-mitosis in endosperm. Chromosoma. 1958;9(4):332–358. doi: 10.1007/BF02568085. [DOI] [PubMed] [Google Scholar]
  9. Mazia D. Chromosome cycles turned on in unfertilized sea urchin eggs exposed to NH4OH. Proc Natl Acad Sci U S A. 1974 Mar;71(3):690–693. doi: 10.1073/pnas.71.3.690. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. McGill M., Brinkley B. R. Human chromosomes and centrioles as nucleating sites for the in vitro assembly of microtubules from bovine brain tubulin. J Cell Biol. 1975 Oct;67(1):189–199. doi: 10.1083/jcb.67.1.189. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Moens P. B. Kinetochore microtubule numbers of different sized chromosomes. J Cell Biol. 1979 Dec;83(3):556–561. doi: 10.1083/jcb.83.3.556. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Nicklas R. B. Mitosis. Adv Cell Biol. 1971;2:225–297. doi: 10.1007/978-1-4615-9588-5_5. [DOI] [PubMed] [Google Scholar]
  13. Pepper D. A., Brinkley B. R. Localization of tubulin in the mitotic apparatus of mammalian cells by immunofluorescence and immunoelectron microscopy. Chromosoma. 1977 Apr 19;60(3):223–235. doi: 10.1007/BF00329772. [DOI] [PubMed] [Google Scholar]
  14. Rieder C. L. Localization of ribonucleoprotein in the trilaminar kinetochore of PtK1. J Ultrastruct Res. 1979 Feb;66(2):109–119. doi: 10.1016/s0022-5320(79)90128-x. [DOI] [PubMed] [Google Scholar]
  15. Rieder C. L. Ribonucleoprotein staining of centrioles and kinetochores in newt lung cell spindles. J Cell Biol. 1979 Jan;80(1):1–9. doi: 10.1083/jcb.80.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Roos U. P. Light and electron microscopy of rat kangaroo cells in mitosis. II. Kinetochore structure and function. Chromosoma. 1973;41(2):195–220. doi: 10.1007/BF00319696. [DOI] [PubMed] [Google Scholar]
  17. Telzer B. R., Moses M. J., Rosenbaum J. L. Assembly of microtubules onto kinetochores of isolated mitotic chromosomes of HeLa cells. Proc Natl Acad Sci U S A. 1975 Oct;72(10):4023–4027. doi: 10.1073/pnas.72.10.4023. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. URETZ R. B., BLOOM W., ZIRKLE R. E. Irradiation of parts of individual cells. II. Effects of an ultraviolet microbeam focused on parts of chromosomes. Science. 1954 Aug 6;120(3110):197–199. doi: 10.1126/science.120.3110.197. [DOI] [PubMed] [Google Scholar]
  19. URETZ R. B., BLOOM W., ZIRKLE R. E. Irradiation of parts of individual cells. II. Effects of an ultraviolet microbeam focused on parts of chromosomes. Science. 1954 Aug 6;120(3110):197–199. doi: 10.1126/science.120.3110.197. [DOI] [PubMed] [Google Scholar]
  20. Weisenberg R. C., Rosenfeld A. C. In vitro polymerization of microtubules into asters and spindles in homogenates of surf clam eggs. J Cell Biol. 1975 Jan;64(1):146–158. doi: 10.1083/jcb.64.1.146. [DOI] [PMC free article] [PubMed] [Google Scholar]

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