Delneri Daniela
Faculty of Life Sciences, The University of Manchester, Manchester, UK.
Methods Mol Biol. 2011;759:271-82. doi: 10.1007/978-1-61779-173-4_16.
Competition experiments are an effective way to provide a measurement of the fitness of yeast strains. The availability of the Saccharomyces cerevisiae yeast knock-out (YKO) deletion collection allows scientists to retrieve fitness data for the ~6,000 S. cerevisiae genes at the same time in a given environment. The molecular barcodes, characterizing each yeast mutant, serve as strain identifiers, which can be detected in a single microarray analysis. Competition experiments in continuous culture using chemically defined media allow a more specific discrimination of the strains based on their fitness profile. With this high-throughput approach, a series of genes that, when one allele is missing, result in either defective (haplo-insufficient) or favored (haplo-proficient) growth phenotype have been discovered, for each nutrient-limiting condition tested. While haplo-insufficient genes seemed to overlap largely across all the media used, the haplo-proficient ones seem to be more environment specific. For example, genes involved in the protein secretion pathway were highly haplo-insufficient in all the contexts, whereas most of the genes encoding for proteasome components showed a haplo-proficient phenotype specific to nitrogen-limiting conditions. In this chapter, the method used for implementation of competition experiments for high-throughput studies in yeast is presented.
竞争实验是衡量酵母菌株适应性的有效方法。酿酒酵母基因敲除（YKO）缺失文库的存在，使科学家能够在给定环境中同时获取约6000个酿酒酵母基因的适应性数据。表征每个酵母突变体的分子条形码可作为菌株标识符，通过单次微阵列分析即可检测到。使用化学成分明确的培养基进行连续培养的竞争实验，能够根据菌株的适应性特征对其进行更具体的区分。通过这种高通量方法，针对每种测试的营养限制条件，已经发现了一系列基因，当其中一个等位基因缺失时，这些基因会导致缺陷（单倍体不足）或有利（单倍体充足）的生长表型。虽然单倍体不足的基因在所有使用的培养基中似乎有很大重叠，但单倍体充足的基因似乎更具环境特异性。例如，参与蛋白质分泌途径的基因在所有情况下都高度单倍体不足，而大多数编码蛋白酶体成分的基因则表现出特定于氮限制条件的单倍体充足表型。本章介绍了用于酵母高通量研究的竞争实验实施方法。
