Delayed reproductive death as a dominant phenotype in cell clones surviving X-irradiation.
Residual damage manifested as reduced cloning efficiency was observed in many of the cloned progeny of Chinese hamster ovary (CHO) cells and human carcinoma SQ-20B cells surviving X-irradiation. This stable phenotype, which we have termed delayed reproductive death, persisted for greater than 50 generations of cell replication post-irradiation. Clones showing this phenotype were aneuploid, and formed colonies with a high proportion of giant cells. By somatic cell hybridization of CHO clones, the delayed reproductive death phenotype was found to be a dominant trait; the cloning efficiency of hybrid clones was persistently depressed, as compared with that of control hybrid cells. These results suggest that delayed reproductive death represents a specific cellular response that may persist in some of the progeny of mammalian cells for long periods after X-irradiation.
Chang
W P
WP
Laboratory of Radiobiology, Harvard University School of Public Health, Boston, MA 02115.
Little
J B
JB
D000818:Animals; D016466:CHO Cells; D002294:Carcinoma, Squamous Cell; D002470:Cell Survival / Q000528:radiation effects*; D002999:Clone Cells / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D006224:Cricetinae; D006801:Humans; D007822:Laryngeal Neoplasms; D010641:Phenotype; D014407:Tumor Cells, Cultured