Maliga P, Svab Z, Harper E C, Jones J D
Advanced Genetic Sciences Inc., Oakland, CA 94608.
Mol Gen Genet. 1988 Nov;214(3):456-9. doi: 10.1007/BF00330480.
Previous studies have shown that a chimeric streptomycin phosphotransferase (SPT) gene can function as a dominant marker for plant cell transformation. The SPT marker previously described by Jones and co-workers has a limited value since it conferred a useful level of resistance only to a fraction (10%) of Nicotiana plumbaginifolia transgenic lines. Expression of resistance was species specific: no such resistant transformants were found in N. tabacum. In this paper we describe an improved SPT construct that utilizes a mutant Tn5 SPT gene. The mutant gene, SPT*, encodes a protein with a two amino acid deletion close to its COOH-terminus. In N. tabacum cell culture the efficiency of transformation with the improved streptomycin resistance marker was comparable to kanamycin resistance. When the chimeric SPT* gene was introduced linked to a kanamycin resistance gene, streptomycin resistance was expressed in most of the transgenic N. tabacum lines.
先前的研究表明，嵌合链霉素磷酸转移酶（SPT）基因可作为植物细胞转化的显性标记。琼斯及其同事先前描述的SPT标记价值有限，因为它仅赋予一小部分（10%）的烟草转基因株系有用水平的抗性。抗性表达具有物种特异性：在烟草中未发现此类抗性转化体。在本文中，我们描述了一种利用突变型Tn5 SPT基因的改良SPT构建体。该突变基因SPT编码一种在其COOH末端附近缺失两个氨基酸的蛋白质。在烟草细胞培养中，改良的链霉素抗性标记的转化效率与卡那霉素抗性相当。当将嵌合SPT基因与卡那霉素抗性基因连锁导入时，大多数转基因烟草株系都表达了链霉素抗性。
