Failure of centromere separation leads to formation of diplochromosomes in next mitosis in okadaic acid treated HeLa cells.

Authors

  • Sibdas Ghosh,

    1. Research Program IV, Division 0430, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, FRG
    2. Department of Botany, University of Calcutta, Calcutta 700019, India.
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  • Neidhard Paweletz,

    Corresponding author
    1. Research Program IV, Division 0430, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, FRG
      Tel: 49 6221 42 3403. Fax: 49 6221 42 3458.
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  • Dieter Schroeter

    1. Research Program IV, Division 0430, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, FRG
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Tel: 49 6221 42 3403. Fax: 49 6221 42 3458.

Abstract

High concentrations of okadaic acid, sufficient to inhibit phosphatase 1 and 2A activities, induces formation of diplochromosomes in HeLa cells. It has been shown that this is due to a failure of sister chromatid separation in earlier mitosis in the presence of okadaic acid in the medium and not due to bypassing of mitosis (endoreduplication). Moreover, it has been demonstrated that the sister chromatid adherence does not depend on any under-replicated chromatin segment shared by the sister chromatids which might happen in okadaic acid induced premature mitosis, but due to the failure of the centromeres to separate at metaphase - anaphase transition. The role of phophatase 1 in sister chromatid separation has been discussed

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