Yeast Ribosomes: Genetics

Abstract

INTRODUCTION The yeasts represent an important class of eukaryotic organisms both from the point of view of their evolutionary position and from their potential importance in molecular biology. The yeast cell contains a nuclear membrane, a nucleolus, a centriole, mitrochrondia, an endoplasmic reticulum, lysosomes, a Golgi body, vacuoles, a plasma membrane and a cell wall. Thus their cellular structure is that of a eukaryotic cell. The genetic information for all of this cellular complexity is contained in the smallest amount of DNA of any eukaryotic cell. Haploid spores of Saccharomyces cerevisiae contain only 0.84 × 10 10 daltons of DNA (Darland 1969), which is equivalent to about three times the DNA content of the E. coli chromosome. The kinetics of thermal renaturation of denatured DNA are consistent with a genome of this size (Bicknell and Douglas 1970). The life cycle in yeast is similar to that found in higher eukaryotic organisms, with a restricted period of DNA synthesis and mitotic and meiotic cell division cycles (Hartwell 1970). For problems in molecular and cellular biology which are common to both prokaryotic and eukaryotic organisms, yeast offers little advantage over the well-studied prokaryotic organisms except that complementation testing is straightforward. However for certain problems on the cellular level which are peculiar to eukaryotic organisms, yeast is the choice organism. In particular, yeast offers a number of distinct advantages for the study of those problems of translation and transcription which are peculiar to eukaryotic organisms. The genetics of yeast is well studied. Genetic analysis...