Introduction

The yeast Saccharomyces cerevisiae is arguably one of the most important fungal organisms used in biotechnological processes. Making bread and alcoholic beverages, yeast has served mankind for several thousands of years. Many enzymes and biological compounds useful in biochemical research have been produced from yeast cells. In the mid-1930s yeast was introduced as an experimental system for molecular biology (Roman, 1981) and has since received increasing attention. The elegance of yeast genetics and the ease of manipulation of yeast, and finally the technical breakthrough of yeast transformation to be used in reverse genetics, have substantially contributed to the enormous growth in yeast molecular biology (Broach et al., 1981; Strathern et al., 1981; Guthrie and Fink, 1991). This success is also due to the fact, which was not anticipated a couple of years ago, that the extent to which basic biological structures and processes have been conserved throughout eukaryotic life is remarkable.

Yeast: an experimental system for molecular biology

Yeast is a versatile eukaryotic model organism

It is now well established that yeast is an ideal system in which cell architecture and fundamental cellular mechanisms can be successfully investigated. Among all eukaryotic model organisms, S. cerevisiae combines several advantages. It is a unicellular organism which, unlike more complex eukaryotes, is amenable to mass production. It can be grown on defined media giving the investigator complete control over environmental parameters.