Crawford B D, Enger M D, Griffith B B, Griffith J K, Hanners J L, Longmire J L, Munk A C, Stallings R L, Tesmer J G, Walters R A
Mol Cell Biol. 1985 Feb;5(2):320-9. doi: 10.1128/mcb.5.2.320-329.1985.
We describe here the derivation, characterization, and use of clonal cadmium-resistant (Cdr) strains of the Chinese hamster cell line CHO which differ in their metallothionein (MT) induction capacity. By nondenaturing polyacrylamide gel electrophoresis, we showed that the stable Cdr phenotype is correlated with the augmented expression of both isometallothioneins (MTI and MTII). In cells resistant to concentrations of CdCl2 exceeding 20 microM, coordinate amplification of genes encoding both isometallothioneins was demonstrated by using cDNA MT-coding sequence probes and probes specific for 3'-noncoding regions of Chinese hamster MTI and MTII genes. Molecular and in situ hybridization analyses supported close linkage of Chinese hamster MTI and MTII genes, which we have mapped previously to Chinese hamster chromosome 3. This suggests the existence of a functionally related MT gene cluster in this species. Amplified Cdr variants expressing abundant MT and their corresponding Cds parental CHO cells should be useful for future studies directed toward elucidating the mechanisms that regulate expression of the isometallothioneins.
我们在此描述了中国仓鼠细胞系CHO的克隆镉抗性（Cdr）菌株的衍生、特性及应用，这些菌株在金属硫蛋白（MT）诱导能力上存在差异。通过非变性聚丙烯酰胺凝胶电泳，我们发现稳定的Cdr表型与两种异构金属硫蛋白（MTI和MTII）表达的增强相关。在对超过20 microM浓度的CdCl2具有抗性的细胞中，使用cDNA MT编码序列探针以及针对中国仓鼠MTI和MTII基因3'-非编码区的特异性探针，证明了编码两种异构金属硫蛋白的基因发生了协同扩增。分子和原位杂交分析支持中国仓鼠MTI和MTII基因紧密连锁，我们之前已将其定位到中国仓鼠3号染色体上。这表明该物种中存在功能相关的MT基因簇。表达大量MT的扩增Cdr变体及其相应的Cds亲本CHO细胞，将有助于未来旨在阐明调节异构金属硫蛋白表达机制的研究。
