Lewis J A, Shimizu K, Zipser D
Mol Cell Biol. 1983 Oct;3(10):1815-23. doi: 10.1128/mcb.3.10.1815-1823.1983.
The Chinese hamster thymidine kinase (TK) gene has been isolated from a recombinant phage library constructed with genomic DNA from mouse Ltk- cells transformed to Tk+ by transfection with Chinese hamster genomic DNA. The phage library was screened by the Benton-Davis plaque hybridization technique, using as probes, subclones of recombinant phage that were isolated from mouse Ltk+ transformants by the tRNA suppressor rescue method. The Chinese hamster TK gene is contained within 13.2 kilobases of genomic DNA in the isolate designated lambda 34S4. This gene, defined by restriction enzyme sensitivity experiments, homology studies with the chicken TK gene, and mRNA blotting experiments, may extend over 8.5 kilobases. Subclones of the lambda 34S4 isolate used as hybridization probes identified a 1,400-nucleotide polyadenylated RNA as the hamster TK mRNA. The abundance of this mRNA varies dramatically in Chinese hamster cells cultured under various growth conditions, providing direct evidence that the growth dependence of TK activity may be regulated in an important way at the level of cytoplasmic TK mRNA.
中国仓鼠胸苷激酶（TK）基因是从一个重组噬菌体文库中分离得到的，该文库是用来自经中国仓鼠基因组DNA转染而转化为Tk+的小鼠Ltk-细胞的基因组DNA构建的。通过Benton-Davis噬菌斑杂交技术对噬菌体文库进行筛选，使用从通过tRNA抑制子拯救方法从小鼠Ltk+转化体中分离得到的重组噬菌体的亚克隆作为探针。中国仓鼠TK基因包含在命名为λ34S4的分离物的13.2千碱基基因组DNA内。通过限制酶敏感性实验、与鸡TK基因的同源性研究以及mRNA印迹实验确定，该基因可能延伸超过8.5千碱基。用作杂交探针的λ34S4分离物的亚克隆鉴定出一种1400个核苷酸的多聚腺苷酸化RNA为仓鼠TK mRNA。在不同生长条件下培养的中国仓鼠细胞中，这种mRNA的丰度变化很大，这直接证明了TK活性对生长的依赖性可能在细胞质TK mRNA水平上以重要方式受到调控。
