2 Yeast Genetics and Strain Construction

This chapter discusses the basic yeast strain construction. The yeast, Saccharomyces cerevisiae, is an excellent model system for the study of many aspects of eukaryote cell biology, genetics, and biochemistry. It has a compact, 16-chromosome genome, of which genes represent approximately 70%. This, in combination with a sophisticated armory of molecular genetic techniques for its genetic manipulation, makes yeast a very approachable model system. The standard approach to constructing new S. cerevisiae strains involves carrying out genetic crosses between haploid strains so that new combinations of genetic markers can be generated. While the facility with which the yeast genome can be engineered using homologous recombination to insert or delete genes or specific alleles has made the construction of yeast strains very easy, it can often be simpler, faster and more reliable to resort to the classical strain construction techniques described in the chapter. The simplicity of the yeast life cycle and the ease with which it can be manipulated makes the application of the suite of methods achievable in most labs, also including those researchers who have no experience of working with S. cerevisiae.