Andrulis I L, Duff C, Evans-Blackler S, Worton R, Siminovitch L
Mol Cell Biol. 1983 Mar;3(3):391-8. doi: 10.1128/mcb.3.3.391-398.1983.
The amino acid analog albizziin was used to isolate Chinese hamster ovary cell lines which overproduce asparagine synthetase. Mutants selected in a single step after ethyl methane sulfonate mutagenesis were approximately 10-fold more resistant to the drug than the parental lines and expressed 8- to 17-fold elevations in enzyme activity. The karyotypes of these lines show alterations such as breaks and translocations affecting the long arm of chromosome 1. Cell lines isolated in several steps by growth in progressively increasing concentrations of albizziin were more resistant to the drug and exhibited up to 300-fold enhancement of asparagine synthetase activity. The multistep albizziin-resistant cell lines usually had expanded chromosomal regions which stained somewhat homogeneously, often on the long arm of chromosome 1. These results suggest that resistance to albizziin in the multistep lines may be due to gene amplification.
氨基酸类似物合欢氨酸被用于分离过量产生天冬酰胺合成酶的中国仓鼠卵巢细胞系。在甲磺酸乙酯诱变后一步筛选出的突变体对该药物的抗性比亲代细胞系高约10倍，且酶活性提高了8至17倍。这些细胞系的核型显示出诸如断裂和易位等改变，影响了1号染色体的长臂。通过在逐渐增加浓度的合欢氨酸中生长分几步分离得到的细胞系对该药物更具抗性，并且天冬酰胺合成酶活性提高了多达300倍。多步抗合欢氨酸细胞系通常具有扩展的染色体区域，这些区域染色有些均匀，通常位于1号染色体的长臂上。这些结果表明，多步细胞系对合欢氨酸的抗性可能是由于基因扩增。
