CRG: Studying yeast provides new insight to genome evolution

CRG: Studying yeast provides new insight to genome evolution

News from CRG

CRG researchers have proposed a new theory to explain the origin of whole genome duplication at the beginning of the yeast lineage. Yeasts are single-celled fungi that originated over 100 million years ago. The ability of these organisms to ferment carbohydrates is widely used for food and drink fermentation. Yeasts are also one of the most commonly used model organisms in research. For example, the yeast Saccharomyces cerevisiae, which is used to make bread, wine and beer, was the first eukaryotic organism to be sequenced (in 1996) and is a key model organism for studying molecular and cellular biology.

Once the yeast genome sequences were available, researchers were able to determine that the yeast genome contains more than 50 repeated fragments. Since then, the scientific community has accepted the theory that yeast underwent a whole genome duplication, a phenomenon that is not isolated and can also be found in other species. For instance, we know that whole genome duplications were important in the early evolution of vertebrates and that it is a very common phenomenon in plants, especially cultivated ones.

The CRG scientists Marina Marcet-Houben and Toni Gabaldón (CRG group leader and ICREA Research Professor) have now studied the origins of the whole genome duplication in yeast to gain a more thorough understanding of this phenomenon, which is thought to have played a key role the evolution and adaption of the species. Their results were published today in the journal PLoS Biology. Unexpectedly, they show that the appearance of duplicated genes was not caused by a simple duplication of the whole genome but rather by a hybridization of two different species. Their proposal, which is at odds with the currently most widely accepted theory in the scientific community, provides new insight into this key process during genome evolution and the origins of species.

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Marina Marcet-Houben and Toni Gabaldón “Beyond the whole genome duplication: phylogenetic evidence for an ancient inter-species hybridization in the baker’s yeast lineage” PLOS Biology. 7th August 2015.