突变体263-H9是利用mTn3转座标签对酿酒酵母(Saccharomyces cerevisiae)W303-1A诱变、筛选得到的。该突变体表现出对多种逆境胁迫(1.5mol/L山梨醇高渗透压胁迫、0.65mol/LNaCI高盐胁迫和15℃低温胁迫)敏感的表型特征,而且与其他突变体不同其转座标签的插入位点是GIP2和YER053C-A的基因间隔区域。本文通过基因敲除、基因组文库功能互补等多种分子生物学和遗传学方法,确定了突变体263-H9的敏感表型不是由于转座标签的插入直接引起的,而是盐胁迫反应信号传导途经中重要的基因PBS2发生部分缺失,造成该基因不能正常表达,而导致的表型变化。
The mutant 263-H9 with hypersensitivity to several stress conditions (1.5 mol/L Sorbitol, 0.65 mol/L NaCI and 15℃) was obtained by using transposon mutagenesis in the Saccharomyces cerevisiae strain W303-1A. Unlike other mutants the transposon in 263-H9 was intergenic between GIP2 and YERO53C-A. Using gene knockout, a yeast genomic library and other methods, the gene correlated with the salt stress response was identified. The data indicated that the phenotype of 263-H9 was not directly caused by the insertion of the transposon. On the other hand, the hypersensitivity to salt and other stress conditions was due to the deletion of 5 base pairs close to position 936bp in the PBS2 gene essential for HOG signal pathway regulation under salt stress.