Descriptions

Outline

Click the species name for a description of the organism

S. pombe

Schizosaccharomyces pombe is the archetypal fission yeast, a simple, unicellular yeast that divides by medial fission. It is distantly related to the budding yeasts, such as Saccharomyces cerevisiae and Candida albicans. In many ways, S. pombe more closely resembles a primitive eukaryote than the more derived budding yeasts.
Schizosaccharomyces pombe has been a major model organism for cell cycle and cell biology research for thirty years. The comparison of the Schizosaccharomyces pombe genome, which was sequenced several years ago, with those of its close relatives, Schizosaccharomyces octosporus and Schizosaccharomyces japonicus will, greatly improve our understanding of the genomes and the proteins they encode.

S. octosporus

Schizosaccharomyces octosporus is a relative of the two other know fission yeast, Schizosaccharomyces japonicus and the well studied fission yeast Schizosaccharomyces pombe. It has a very similar life style to S. pombe, the major difference being its eight-spored ascii.

S. japonicus

Unlike other fission yeasts, Schizosaccharomyces japonicus readily adopts a invasive, hyphal growth form. Such growth is an important virulence trait in pathogenic fungi, making Schizosaccharomyces japonicus, a potentially important model for fungal disease.
In addition, the three fission yeast form an early-branching clade among the Ascomycete (ascus-forming) fungi, which include yeast, hyphal fungi, and truffles. Comparison within the Schizosaccharomyces and between them and other Ascomycetes should provide insight into the evolution of multicellular fungi and eukaryotes, in general.

S. cryophilus

Schizosaccharomyces cryophilus is the most recently described fission yeast. Well over 100 fission yeast samples are stored in strain collections around the world, all of which were believed to belong to the S. pombe, S. octosporus or S. japonicus species. In screening these for divergent sequences, Peter Baumann and colleagues at the Stowers Institute identified one isolate clearly different at the sequence level from the three known species. The isolate first arose as a contaminant in handling S. octosporus stocks. S. cryophilus is indeed most closely related to S. octosporus, but the two are still as distantly related as humans and mouse. It gets its name from a preference for growth at a lower temperature than other fission yeast species.