Abstract
Mammalian metaphase chromatin has been isolated by an ultrasonication technique and examined by both surface scanning and high-voltage electron microscopy (H.V.E.M.). By both techniques, rod-like structures 0.5 to 0.8 μ wide and varying in length from 3 to 5 μ were seen. Evidence is submitted that these represented parts of metaphase chromosomes. — By scanning microscopy the rods showed repeated patterns of wide and constricted areas. The constrictions were spaced 3,000 to 4,000 Å apart and the entire surface of the rods was covered with smaller rounded projections. In addition, longitudinal grooves were occasionally seen. — H.V.E.M. revealed gross folded and unfolded fibres whose sizes correlated with the surface projections seen by scanning microscopy. In addition, microfibrils, 20–40 Å in diameter were seen. The possibility that these fibrils represent the DNA co-helix is discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Anderson, T. F.: Techniques for preservation of 3-dimensional structure in preparing specimens for electron microscopy. Trans. N. Y. Acad. Sci.13, 130–134 (1951).
Bajer, A.: Ciné-micrographic studies on mitosis in endosperm. V. Formation of the metaphase plate. Exp. Cell Res.15, 370–383 (1958).
—, Allen, R. D.: Structure and organization of the mitotic spindle of livingHaemanthus endosperm. Science151, 572–574 (1966).
Christenhuss, R., Buchner, Th., Pfeiffer, R. A.: Visualization of human somatic chromosomes by scanning electron microscopy. Nature (Lond.)216, 379–380 (1967).
Clarke, J. A., Salsbury, A. J.: Surface ultramicroscopy of human blood cells. Nature (Lond.)215, 402–404 (1967).
— —, Rowland, G. F.: Surface ultrastructure of human leucocytes, mouse macrophages and rat liver cells and of isolated nuclei and nucleoli. Brit. J. Haemat.14, 533–542 (1968).
Claude, A., Potter, J. S.: Isolation of chromatin threads from the resting nucleus of leukaemic cells. J. exp. Med.77, 345–354 (1943).
Cole, A.: The structure of chromosomes. In: Theoretical and experimental biophysics (ed. by A. Cole), p. 305–375. London: E. Arnold Ltd.; New York: M. Dekker Inc. 1967.
Coulson, A. S., Chalmers, D. G.: Lack of demonstrable IgG in PHA-stimulated human transformed cells cultured in a serum-free medium. Immunology12, 417–429 (1967).
Darlington, C. D.: The chromosome as a physico-chemical entity. Nature (Lond.)176, 1139–1144 (1955).
Denues, A. R. T.: On the identity of isolated chromosomes. II. Distorted nuclei in the production of chromatin threads. Exp. Cell Res.4, 333–343 (1953).
Dewey, W. C., Furman, S. C., Robinette, S. M.: Comparison of lethality and chromosomal damage induced by x-rays in synchronous chinese hamster cells in vitro. Radiation Res. (in press, 1969).
DuPraw, E. J.: The organization of nuclei and chromosomes in honey bee embryonic cells. Proc. nat. Acad. Sci. (Wash.)53, 161–165 (1965).
—: Evidence for a “folded-fibre” organization in human chromosomes. Nature (Lond.)209, 577–581 (1966).
Ford, E. H. R., Thurley, K., Woollam, D. H. M.: Electron-microscopic observations on whole human mitotic chromosomes. J. Anat. (Lond.)103, 143–150 (1968).
Fuller, W.: The molecular structure of the nucleic acids and their biological significance. In: Genetic elements (ed. by D. Shugar), p. 17–38. London and New York: Acad. Press 1967.
Gall, J. G.: Chromosome fibers from an interphase nucleus. Science139, 120–121 (1963).
—: Chromosome fibers studied by a spreading technique. Chromosoma (Berl.)20, 221–233 (1966).
Hayes, T. L., Pease, R. S. W.: The scanning electron microscope: principles and applications in biology and medicine. Advanc. biol. med. Phys.12, 85–137 (1968).
Hovanitz, W.: An electron microscope study of isolated chromosomes. Genetics32, 500–504 (1947).
Lamb, W. G. P.: The isolation of threads from interphase nuclei. Exp. Cell Res.1, 571–581 (1950).
Mirsky, A. E., Ris, H.: Isolated chromosomes. J. gen. Physiol.31, 1–6 (1947a).
— —: Chemical composition of isolated chromosomes. J. gen. Physiol.31, 7–18 (1947b).
— —: Composition and structure of isolated chromosomes. J. gen. Physiol.34, 475–492 (1951).
Pardon, J. F., Wilkins, M. H. F., Richards, B. M.: A super-helical model for nucleohistone. Nature (Lond.)215, 508–509 (1967).
Polli, E. E.: Human isolated chromosomes. Normal and pathological chromosomes of leucocytes. Experientia (Basel)7, 138–140 (1951).
—: The isolated chromosomes from erythrocytes of various vertebrates. Chromosoma (Berl.)4, 621–629 (1952).
Ris, H.: Ultrastructure of the animal chromosome. In: Regulation of nucleic acid and protein biosynthesis (ed. by V. V. Koningsberger and L. Bosch) p. 11–21. Amsterdam: Elsevier Corp. 1967.
Salsbury, A. J., Clarke, J. A.: A new method for the detection of changes in the surface appearance of human red blood cells. J. clin. Path.20, 603–610 (1967).
Schneider, L. E.: The microscopic three-dimensional viewing of mammalian chromosomes. Exp. Cell Res.47, 658–660 (1967).
Stevens, L. J.: Electron microscopy of unsectioned human chromosomes. Ann. hum. Genet.31, 267–275 (1967).
Terzakis, J. A.: Uranylacetate, a stain and a fixative. J. Ultrastruct. Res.22, 168–184 (1968).
Wolfe, S. L.: The fine structure of isolated chromosomes. J. Ultrastruct. Res.12, 104–112 (1965a).
—: The fine structure of isolated metaphase chromosomes. Exp. Cell Res.37, 45–53 (1965b).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Clarke, J.A., Rowland, G.F. & Salsbury, A.J. The surface and internal structure of metaphase chromatin. Chromosoma 29, 74–87 (1970). https://doi.org/10.1007/BF01183662
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01183662