By May 1996, the first complete genome sequence of a eukaryote - the yeast Saccharomyces cerevisiae - was obtained. Eukaryotic cells store their DNA in membrane-bound nuclei and have organized subcellular compartments (organelles like mitochondria, Golgi bodies, and centrioles). Prokaryotes lack such features, and overall have a simpler structure. Bacteria, bluegreen algae, and archaea are prokaryotes; other cells, like yeast, and all multicellular organisms are eukaryotes.
Saccharomyces cerevisiae has had a long, distinguished role in human history; it is the yeast used by bakers and brewers.
When the yeast genome sequence was obtained, it was the largest genome sequenced to date. It contains just over 12 million base pairs packaged in 16 chromosomes. Yeast have approximately 6,000 genes in all. About a third of these genes are related to human genes; they have survived with relatively little alteration over the one billion years of evolution that separate humans and yeast, suggesting that they carry out important basic functions in cellular life.
Last Reviewed: May 9, 2013