Baker’s Yeast

Saccharomyces cerevisiae, also known as baker’s yeast, is one of the most useful beings known to humans. We rely on it for making bread and beer; but it is also a denizen of the laboratory, one of the most studied organisms on the planet. Which is why I’m nominating it for Life-form of the Month: June.
Yeasts are lowly beings: they have but a single cell. But that doesn’t mean they aren’t mighty. Baker’s yeast, in particular, has proven to have some powerful attributes. Especially in the laboratory. For one thing, it grows easily and fast — it can go through several generations between the time you have your morning toast and your evening beer.

Compared to us, Saccharomyces cerevisiae has few genes — it has around 6,500, while we have more than three times that many. All the same, the study of this organism has illuminated many aspects of human biology. It is, for example, an important tool for studying diseases of the nervous system like Friedreich’s ataxia, an inherited condition that inflicts, among other things, slurred speech and stumbling gaits on those who have it.

This may seem bizarre. How can an organism with one cell — and no nervous system — be useful for studying the degeneration of the human nervous system? There are a couple of parts to the answer.