Biswas D K, Hartigan J A, Pichler M H
Science. 1984 Aug 31;225(4665):941-3. doi: 10.1126/science.6089335.
Bromodeoxyuridine (BrdUrd) treatment of the prolactin nonproducing subclone of GH cells (rat pituitary tumor cells) induces amplification of a 20-kilobase DNA fragment including all of the prolactin gene coding sequences. This amplified DNA segment, which is flanked by two unamplified regions, thus designates a unit of BrdUrd-induced amplified sequence. Cloned DNA segments, 10.3 kilobases long, from the 5' end of the rat prolactin gene of BrdUrd-responsive and -nonresponsive cells, were ligated to the thymidine kinase gene of herpes simplex virus type 1 (HSV1TK), and the hybrid DNA was transferred to thymidine kinase-deficient mouse fibroblast cells by transfection. The HSV1TK gene and the rat prolactin gene were amplified together in drug-treated transfectants carrying the hybrid DNA HSV1TK gene and rat prolactin gene of BrdUrd-responsive GH cells. These results suggest that the 10.3-kilobase DNA segment at the 5' end of the rat prolactin gene of BrdUrd-responsive GH cells carries the information for drug-induced gene amplification (amplicon) and that another gene, such as the HSV1TK gene, is also amplified when the latter is placed adjacent to this segment.
用溴脱氧尿苷（BrdUrd）处理生长激素（GH）细胞（大鼠垂体瘤细胞）的不产生催乳素的亚克隆，可诱导一个包含所有催乳素基因编码序列的20千碱基DNA片段发生扩增。这个扩增的DNA片段两侧是两个未扩增区域，因此它代表了BrdUrd诱导的扩增序列单位。从对BrdUrd有反应和无反应的细胞的大鼠催乳素基因5'端克隆出的10.3千碱基长的DNA片段，与单纯疱疹病毒1型（HSV1TK）的胸苷激酶基因连接，然后通过转染将杂交DNA转移到胸苷激酶缺陷的小鼠成纤维细胞中。在携带来自对BrdUrd有反应的GH细胞的杂交DNA HSV1TK基因和大鼠催乳素基因的药物处理转染子中，HSV1TK基因和大鼠催乳素基因一起被扩增。这些结果表明，对BrdUrd有反应的GH细胞的大鼠催乳素基因5'端的10.3千碱基DNA片段携带了药物诱导基因扩增（扩增子）的信息，并且当另一个基因，如HSV1TK基因，与该片段相邻放置时，它也会被扩增。
