Pombe

Schizosaccharomyces pombe, commonly known as fission yeast or pombe, is a unicellular eukaryotic microorganism widely used as a model organism in molecular and cell biology. It belongs to the fungi and is studied for its clear cell biology, simple growth requirements, and genetic tractability. Cells are typically rod-shaped and divide by medial fission, producing two daughter cells in a single plane.

Pombe reproduces asexually by fission and, under nutrient limitation, can switch to sexual reproduction. In the sexual cycle, haploid cells of opposite mating types mate to form a diploid zygote, which can undergo meiosis to generate four haploid spores within an ascus. This lifecycle makes it a convenient system for studying cell division, gene expression, and chromosomal behavior.

The genome of Schizosaccharomyces pombe is roughly 14 megabases in size, organized on three chromosomes and encoding about 4,800 to 5,000 protein-coding genes. It has been fully sequenced and extensively annotated. The organism supports numerous genetic tools, and many laboratory strains and deletion libraries are available. It also features an RNA interference pathway and well-characterized heterochromatin, aiding studies of gene regulation and chromosomal biology.

Pombe is a prominent model for conserved eukaryotic processes such as cell cycle control, DNA replication, genome maintenance, and cytokinesis. Its simplicity and evolutionary conservation complement insights from other yeasts and higher eukaryotes, making it a staple in basic research and biotechnology laboratories worldwide.