Chromosomal breakage following treatment of CHO‐K1 Cells in Vitro With U‐68,553B is due to Induction of Undercondensation of Heterochromatin

@article{Yu1992ChromosomalBF,
  title={Chromosomal breakage following treatment of CHO‐K1 Cells in Vitro With U‐68,553B is due to Induction of Undercondensation of Heterochromatin},
  author={R L Yu and C. S. Aaron and Roger G. Ulrich and Arul Thilagar and P V Kumaroo and Y. Wang},
  journal={Environmental and Molecular Mutagenesis},
  year={1992},
  volume={20}
}
Preferential breakage of chromosomes af specific sites (so‐called “fragile sites”) has been observed to occur spontaneously, and has been induced by some metal salts and chemicals. Furthermore, a heterochromatic region of the long arm of the Chinese hamster ovary (CHO) M‐chromosome is known to be suceptible to a disproportionately high frequency of spontaneous breakage; unless there is physical displacement of chromatin the resulting achromatic lesions are not scored as structural aberrations… 
Sodium arsenite-induced chromosomal aberrations in the Xq arm of Chinese hamster cell lines.
TLDR
An increased number of abnormal cells with pulverised chromosomes, decondensed chromatin, isochromosomes and hyperploidy in CHO9 and EM-C11 cell lines at all doses of SA is observed and a high degree of fragility of these regions is observed.
Localized Chromosomal Aberrations in the Heterochromatic q Arm of the X Chromosome in V79 Chinese Hamster Cells and the Implications for Industrial in vitro Cytogenetic Screening
TLDR
Comparisons between different assays reveal significant discrepancies between the results obtained, and in vitro chromosomal aberration assay, in particular, has been criticized for leading to too many positive results.
Chromosomal Alterations

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