酿酒酵母转座标签插入突变体263-H9中高盐胁迫基因的确定

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(1.5 mol/L山梨醇高渗透压胁迫、0.65 mol/L NaCl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。

Identification of the Gene Correlated with Salt Stress in the Saccharomyces cerevisiae 263-H9 Mutant

The mutant 263-H9 with hypersensitivity to several stress conditions (1.5 mol/L Sorbitol, 0.65 mol/L NaCl and 15 degrees C) 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 YER053C-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 936 bp in the PBS2 gene essential for HOG signal pathway regulation under salt stress.