A nice glass of sake might not make you think of your dog. But both are the result of long domestication processes. Humans have domesticated an awful lot of organisms, from pets to grains to the fungus that breaks down starches in the production of sake, soy sauce and miso.
To learn more about microbe domestication, a research team compared the genome of Aspergillus oryzae, the fungus responsible for Japanese cuisine, with that of its wild relative Aspergillus flavus.
The wild child is a problem. It makes grains rot and can produce aflatoxin, a potent carcinogen. The destructive fungus shares 99.5 percent of its genome with its miso-making cousin. [John G. Gibbons et al., "The Evolutionary Imprint of Domestication on Genome Variation and Function of the Filamentous Fungus Aspergillus oryzae" in Current Biology]
The tiny differences in the genomes suggest that selection during breeding affected genes related to the fungus' metabolism. In contrast, plant and animal domestication usually targets developmental processes: fruits get juicier, chickens grow bigger breasts, and grains lose their hard outer casings.
Thanks to the early sake makers who selected as they did, we can enjoy the byproducts of this microbe's metabolism today. Kanpai!
[The above text is a transcript of this podcast.]