Contrary to an earlier report suggesting clonal immortality in Paramecium caudatum, the clones of the same species in this study terminated inevitably with a maximal life-span of 658 fissions and showed, prior to clonal death, decreased fission rate, increased probability of the appearance of non-dividing or dead cells after cell division, and increased frequency of morphological abnormality and of division asynchrony. Clonal senescence and death after a limited number of fissions was reproducible even if subclones derived from the original clone of a known fission age were examined again after a lag of 468 days. These results indicate that clones of P. caudatum are mortal and that they use fissions, not days, to measure life-span. Possible causes for the discrepancies between the earlier report and the present one are discussed.
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JOURNAL ARTICLE| 01 February 1980
Clonal death associated with the number of fissions in Paramecium caudatum
Online Issn: 1477-9137
Print Issn: 0021-9533
© 1980 by Company of Biologists
J Cell Sci (1980) 41 (1): 177–191.
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Y. Takagi, M. Yoshida; Clonal death associated with the number of fissions in Paramecium caudatum. J Cell Sci 1 February 1980; 41 (1): 177–191. doi: https://doi.org/10.1242/jcs.41.1.177
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