Abstract
The structure of the dinoflagellate chromosome is examined using spread whole mounts and serial sectioning. Evidence is presented that the chromosome is composed of a toroidal bundle of DNA strands which is coiled plectonemically into a tight double helix. This structure is apparent in interphase whole-mount chromosomes and by careful analysis of serial sectioning can be shown in all mitotic stages. It is particularly apparent in the arms of replicating “Y” shaped chromosomes which often uncoil slightly (either naturally or as a result of the fixation used). A model is presented which is based on these results and recent genetic and biochemical data.
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Oakley, B.R., Dodge, J.D. Evidence for a double-helically coiled toroidal chromonema in the dinoflagellate chromosome. Chromosoma 70, 277–291 (1979). https://doi.org/10.1007/BF00328766
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DOI: https://doi.org/10.1007/BF00328766