Chang W P, Little J B
Laboratory of Radiobiology, Harvard University School of Public Health, Boston, MA 02115.
Mutat Res. 1992 Nov 16;270(2):191-9. doi: 10.1016/0027-5107(92)90130-t.
Certain clonal progeny of Chinese hamster ovary (CHO) cells surviving X-irradiation demonstrate pleomorphic changes including a persistently decreased cloning efficiency, a dominant phenotype we have termed delayed reproductive death (Chang and Little, 1991, 1992b). We now report that cells from these progeny clones show a persistently elevated frequency of spontaneous mutations at the hprt locus for up to 95-100 population doublings post-irradiation. Mutant fractions as high as 10(-3) were scored, more than two orders of magnitude higher than those observed in clonal progeny of non-irradiated cells studied in parallel. These results are discussed in terms of the hypothesis that radiation induces a type of genetic instability among some surviving cells that results in a heritable mutator phenotype, and that this instability may also be involved in the phenomenon of delayed reproductive death.
经X射线照射后存活的中国仓鼠卵巢（CHO）细胞的某些克隆后代表现出多形性变化，包括克隆效率持续降低，这是一种我们称为延迟生殖死亡的显性表型（Chang和Little，1991年，1992b）。我们现在报告，这些后代克隆的细胞在照射后多达95 - 100次群体倍增时，hprt位点的自发突变频率持续升高。高达10(-3)的突变率被记录下来，比平行研究的未照射细胞的克隆后代中观察到的突变率高出两个数量级以上。这些结果根据以下假设进行讨论：辐射在一些存活细胞中诱导了一种遗传不稳定性，导致可遗传的突变体表型，并且这种不稳定性可能也与延迟生殖死亡现象有关。
