Nestat M A, Benevolenskiĭ S V, Dutova T A, Tolstorukov I I
Genetika. 1987 Sep;23(9):1525-34.
The red adenine-dependent mutants ade1 of the yeast Pichia pinus blocked in the VI step of adenine biosynthesis (lack of AIR-carboxylase) and ade2 mutants blocked in the VII step of adenine biosynthesis (lack of SAIKAR-synthase) were transformed with the plasmid pYE(ADE2)2 containing ADE2 gene of Saccharomyces cerevisiae encoding AIR-carboxylase. The appearance of white Ade+ clones with the frequency 2-7.10(-8) (which is ten-fold higher than reversion frequency) was only observed in the case of ade2 transformation. Genetic analysis points to connection of the "illegitimate" transformants' appearance with the change in the mutant ade2 locus or in a locus closely linked to the former. Ade+ phenotype was stable during 20 generations of mitotic budding. Southern blotting assay of transformant chromosomal DNA indicates that reconstitution of ade2 defective gene is related with its "correction", owing to integration of pYE(ADE2)2 sequence in the vicinity of the mutant locus.
在腺嘌呤生物合成的第六步受阻（缺乏AIR羧化酶）的酵母毕赤酵母红色腺嘌呤依赖型突变体ade1和在腺嘌呤生物合成的第七步受阻（缺乏SAIKAR合酶）的ade2突变体，用含有编码AIR羧化酶的酿酒酵母ADE2基因的质粒pYE(ADE2)2进行转化。仅在ade2转化的情况下观察到出现频率为2-7×10⁻⁸的白色Ade⁺克隆（比回复频率高十倍）。遗传分析表明“非法”转化体的出现与突变体ade2位点或与其紧密连锁的位点的变化有关。Ade⁺表型在有丝分裂出芽的20代中是稳定的。转化体染色体DNA的Southern印迹分析表明，ade2缺陷基因的重建与其“校正”有关，这是由于pYE(ADE2)2序列整合到突变位点附近所致。
