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本文报道优选基于ＳＶ４０的短暂复制型穿梭质粒ｐＳ１８９和新生儿羊膜上皮细胞ＦＬＣⅢ—２亚克隆，组成穿梭质粒／哺乳动物细胞诱变检测系统。该系统中ＳｕｐＦ的自发突变型频率仅为１．７×１０－５，低于已报道的其它短暂复制型质粒和该质粒在其它细胞中复制时ＳｕｐＦ基因的自发突变率。各种剂量的ＭＮＮＧ的诱发突变频率随诱变剂剂量的增加而升高。ＭＮＮＧ对ＦＬ细胞毒性较大，仅０．３２μｇ／ｍｌ就可使ＦＬ几乎完全失去生长分裂形成克隆的能力，但在短时期内对依赖于病毒复制起点的ＤＮＡ复制效率影响不大，突变频率却显著升高。突变质粒的限制性内切酶分析和靶基因的ＰＣＲ分析等表明，检出突变大多数为点突变或微小缺失，该系统具有方便快速检出点突变的能力，可成为检测诱变剂、抗诱变剂作用强度和特性的分子检测系统。
In this paper, the transient replication shuttle plasmid pS189 based on SV40 and the subclone of neonatal amniotic epithelial cells FLCIII-2 are selected to constitute a shuttle plasmid/mammalian cell mutagenesis detection system. The spontaneous mutation frequency of SupF in this system is only 1.7×10-5, which is lower than the spontaneous mutation rate of the SupF gene when other transiently replicating plasmids have been reported and the plasmid replicates in other cells. The frequency of induced mutations of various doses of MNNG increased with the dose of mutagen. MNNG is more toxic to FL cells, only 0.32μg/ml can make FL almost completely lose the ability to grow and split to form clones, but in a short period of time has little effect on the DNA replication efficiency dependent on the origin of virus replication, but the mutation frequency Significantly higher. Restriction endonuclease analysis of the mutated plasmid and PCR analysis of the target gene showed that most of the detected mutations were point mutations or micro deletions. The system has the ability to quickly and easily detect point mutations, and can be used as a detection mutagen and resistance. Molecular detection system for the strength and properties of mutagens.