Strausberg R L, Butow R A
Proc Natl Acad Sci U S A. 1977 Jul;74(7):2715-9. doi: 10.1073/pnas.74.7.2715.
A protocol is introduced for probing the organization and regulation of expression of the yeast mitochondrial genome, termed "zygotic gene rescue." The procedure is based on the notion that genes retained on mitochondrial DNA of on the notion that genes retained on mitochondrial DNA of petites can be expressed in zygotes of a cross between petite and wild type. To test the validity of this notion, we have taken advantage of our ability to discriminate, by mobility differences on sodium dodecyl sulfate/polyacrylamide gels, different forms of the product of alleles of the mitochondrial gene, varI. In petite strains that have retained the varI gene, its characteristic product appears in zygotes 4-5 hr after mating; no product is observed in petite strains deleted in the varI locus. Our studies indicate that (i) expression in the zygote of the varI gene in the petite genome is not exclusively the result of recombination with mitochondrial DNA of the wild-type tester, and (ii) the varI gene is probably reiterated in the petite mitochondrial genome. The strength of the technique of zygotic gene rescue in the analysis of the mitochondrial genome is discussed.
本文介绍了一种用于探究酵母线粒体基因组表达的组织和调控的方法，称为“合子基因拯救”。该方法基于这样一种观念，即小菌落线粒体DNA上保留的基因可以在小菌落与野生型杂交的合子中表达。为了验证这一观念的有效性，我们利用了通过十二烷基硫酸钠/聚丙烯酰胺凝胶上的迁移差异来区分线粒体基因varI等位基因不同形式产物的能力。在保留了varI基因的小菌落菌株中，其特征性产物在交配后4-5小时出现在合子中；在varI基因座缺失的小菌落菌株中未观察到产物。我们的研究表明：（i）小菌落基因组中varI基因在合子中的表达并非完全是与野生型测试菌株的线粒体DNA重组的结果；（ii）varI基因可能在小菌落线粒体基因组中重复存在。本文还讨论了合子基因拯救技术在分析线粒体基因组方面的优势。
