TRANSGENIC CHINESE HAMSTER V79 CELL-LINES WHICH EXHIBIT VARIABLE LEVELS OF GPT MUTAGENESIS
TRANSGENIC CHINESE HAMSTER V79 CELL-LINES WHICH EXHIBIT VARIABLE LEVELS OF GPT MUTAGENESIS
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DOI：
10.1002/em.2850160102
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发表时间：
1990-01-01
影响因子：
2.8
通讯作者：
ROSSMAN, TG
中科院分区：
文献类型：
--
作者：
KLEIN, CB;ROSSMAN, TG
编码黄嘌呤-鸟嘌呤磷酸核糖转移酶的大肠杆菌gpt基因已稳定转染HPRT-中国仓鼠V79细胞。已经建立了几种gpt细胞系，其甚至在长期培养而不选择gpt后仍保留序列。在6-硫代鸟嘌呤（6 TG）选择中，每个细胞系都表现出特征性的自发突变频率（10-5至10-2）。虽然对大多数细胞系来说，对gpt-的自发突变发生得相当频繁，但它与质粒整合位点的数目或质粒序列的缺失无关。一个转基因细胞系（g12），其持续保持低的自发突变频率（约3 × 10）。10-5）用于与野生型V79细胞（gpt vs. hprt）的比较诱变研究。烷基化剂，如N-甲基-N-亚硝基胍（MNNG）和β-氨基胍。丙内酯（BPL）在g12和V79细胞中显示出同样的毒性和致突变性。紫外线和X射线对这两种细胞系也具有同样的毒性。然而，g12转染子的gpt基因座比野生型V79细胞的内源性hprt对UV敏感2 - 3倍，对X射线诱变敏感2.5-4.5倍。这里提出的数据表明，g12细胞可能是有用的研究哺乳动物诱变剂，产生有限的反应，在hprt基因座。未来的研究计划与这些转基因细胞和其他转基因系比较突变和修复相同的基因（gpt）在不同的整合位点在哺乳动物细胞。
The Escherichia coli gpt gene coding for xanthine-guanine phosphoribosyl transferase has been stably transfected into HPRT- Chinese hamster V79 cells. Several gpt- cell lines have been established, which retain the sequence(s) even after long-term culture without selection for gpt. Each cell line exhibits a characteristic spontaneous mutation frequency (10-5 to 10-2) in 6-thioguanine (6TG) selection. While spontaneous mutagenesis to gpt- occurs rather frequently for most cell lines, it connot be correlated with either the number of plasmid integration sites or deletion of the plasmid sequence(s). One transgenic cell line (g12), which continously maintains a low spontaneous mutation frequency (.apprx.3 .times. 10-5), was used in comparative mutagenesis studies with wild-type V79 cells (gpt vs. hprt). Aklylating agents such as N-methyl-N-nitrosoguanidine (MNNG) and .beta.-propiolactone (BPL) are shown to be equally toxic and mutagenic in both g12 and V79 cells. UV and X-rays are also equally toxic to both cells lines. The gpt locus of the g12 transfectants, however, is two to three times more sensitive to UV and 2.5-4.5 times more sensitive to X-ray mutagenesis than the endogenous hprt of wild-type V79 cells. The data presented here suggests that g12 cells may be useful to study mammalian mutagenesis by agents which yield limited response at the hprt locus. Future studies with these transgenic cells and other transgenic lines are planned to compare the mutability and repair of the same gene (gpt) at different integration sites in mammalian cells.