Why yeast?

Saccharomyces cerevisiae (budding yeast or baker’s yeast) is the best characterized eukaryotic organism widely used as a model for the investigation of almost all biological processes of eukaryotic cell. It is easy to grow, fast dividing, non-pathogenic and particularly suitable for targeted genetic modification. It’s importance in industry and scientific research is also highlighted by the fact that S. cerevisiae 13 Mb genome was the first eukaryotic genome that was completely sequenced. Although S. cerevisiae is a single-celled fungus, it shares a lot of similarities with higher eukaryotes. About 80 human genes complement yeast mutations and about 150 yeast genes are homologous to human disease genes. This microscopic organism also exhibits various features generally assigned to complex, animal organisms including mating, aging and death.

Unlike most other eukaryotes, S. cerevisiae can exist in both haploid and diploid state and reproduces by budding (fig 1). Diploid cells can sporulate and give rise to four haploid ascospores that can be separated using micromanipulation techniques to recover haploid strains. Thus, recessive mutations can be conveniently isolated and manifested in haploid strains, whereas particular diploid strain can be constructed by mating two appropriate haploid strains.

Fig 1. Saccharomyces cerevisiae life cycle. Diploid and haploid cell cycle are interconnected by sexual reproduction because diploid cell can undergo meiosis giving rise to four haploid cells while mating of two sexually different haploids (a and α) results in a diploid cell.

Project aim

Most, if not all, organisms age and die, but it is not clear whether aging and death are just unavoidable consequences of life or if these processes have some evolutionary advantage and are genetically controlled. Our group is challenged by the question why eukaryotic cells age and die? To shed more light on this issue, using the advantages of yeast experimental system (see above), this project focuses on investigation of endogenous causes and deleterious molecular processes leading to cell death.