Characterization of revertants of the CHO EM9 mutant arising during DNA transfection.
Characterization of revertants of the CHO EM9 mutant arising during DNA transfection.
复制标题
DNA 转染过程中产生的 CHO EM9 突变体回复体的表征。
DOI：
10.1093/carcin/12.5.805
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发表时间：
1991
期刊：
影响因子：
4.7
通讯作者：
Thompson,LH
中科院分区：
文献类型：
--
作者：
Barrows,LR;Paxton,MB;Kennedy,KA;Thompson,LH
We have studied reversion in DNA repair deficient EM9 cells, by selection for ethybnethanesulfonate (EMS) resistance. EM9 is a mutant CHO cell line that is hypersensitive to killing by EMS and X-rays and deficient in DNA single-strand break (SSB) repair. EM9 cells were transfected with DNA from a cosmid library, and transfectants resistant to EMS were isolated. Four revertant lines were obtained, which varied in then- sensitivity to killing by EMS, ionizing radiation and other genotoxic agents. When the cell lines were analyzed for resistance to killing by chlorodeoxyuridine (CldUrd) orN-methyl-N′-nitro-N-nitrosoguanidine (MNNG), a different relative ranking among the cell lines was observed. The recently cloned humanXRCC1gene is capable of correcting the deficiencies of the EM9 cell line. Using the humanXRCC1cDNA (pXR1-30) as a probe, we determined that the resstant-transfectant cell lines contained only the endogenous hamsterXRCC1gene, implying that a hamsterXRCC1gene was altered during the transfection/selection procedure and was responsible for the EMS resistance. In these cells the levels ofXRCC1mRNA corresponded roughly to the degrees of resistance of the reverted cell lines to killing by EMS or X-rays. The degree of increased resistance to killing by EMS or X-rays also roughly correlated with increased SSB repair. These results suggest that increased cellular levels of the endogenousXRCC1gene mRNA may largely, though not completely, explain the phenotypes of revertant, EMS-resistant EM9 cell lines.
影响因子：
3.3
作者：
MALIDE, D;RUSSO, P;BENDAYAN, M
通讯作者：
BENDAYAN, M