I love it when we learn outrageous new things about model organisms, so well trodden, that have become even "boring". The yeast Saccharomyces cerevisiae must be one of the best known and analyzed eukaryotes out there, and yet -as it turns out- we know surprisingly little about how they live outside the four walls of the lab... well, except maybe about how they help us make nice food and drink.
A recent study by Stefanini and colleagues in PNAS, and accompanying commentary by Blackwell & Kurtzman, tell us about the life and times of Saccharomyces species in the wild, where they... uh, normally live. As it turns out, these guys love to get cozy in the gut of Polistes dominula social wasps, which provide the right environment to live through the winter, induce sporulation, germination and mating. Gut passage provides conditions conducive to outcrossing, explaining high rates of strain diversity in S. cerevisiae. Remarkably, S. paradoxus, which survives in the wild and rarely mates with S. cerevisiae, can be found in the wasp gut, but does not survive there unless it undergoes interspecific hybridization with S. cerevisiae. Thus, as the authors put it, the wasp gut provides an " environmental alcove in which yeast cells can meet and mate". I prefer fresh linens and a fireplace but, hey, that's just me!
Isn't it remarkable what we can still discover about good old baker's yeast? I love science!
For the record, Nature Microbiology is very interested in the study of yeast populations in the wild and their interactions with their natural hosts, as exemplified by the study of S. paradoxus speciation by Landry and colleagues in our first issue (and as I alluded to in an earlier post).