Higher order structure in metaphase chromosomes (original) (raw)

Abstract

The morphology of metaphase chromosome-derived chromatin fibers released from cells by non-ionic detergent cell lysis in the presence of divalent cations has been studied by electron microscopy. In these preparations the euchromatic arms appear as a series of loops, 200–300 Å in diameter, which are composed of closely-apposed nucleosome arrays. The higher order fiber in chromosomes derived from detergent-lysed cells appears to be less stable than chromatin fibers obtained by mechanical cell lysis. The fiber breaks down into a series of non-uniform nucleosome aggregates (superbeads) and finally to chromatin in a beads-on-a-string morphology upon incubation at 31° for 20 min. These observations allow us to suggest a relationship between uniform thick fibers, superbead-containing fibers, and beads-on-a-string chromatin within metaphase chromosomes.

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References

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Authors and Affiliations

1. Department of Molecular Biology and Biochemistry, University of California, 92717, California, Irvine, USA
   J. B. Rattner & B. A. Hamkalo
2. Department of Developmental and Cell Biology, University of California, 92717, California, Irvine, USA
   B. A. Hamkalo

Authors

1. J. B. Rattner
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2. B. A. Hamkalo
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Rattner, J.B., Hamkalo, B.A. Higher order structure in metaphase chromosomes.Chromosoma 69, 373–379 (1978). https://doi.org/10.1007/BF00332140

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• Received: 03 August 1978
• Accepted: 07 August 1978
• Issue Date: January 1978
• DOI: https://doi.org/10.1007/BF00332140

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