The baker's yeast Saccharomyces cerevisiae has been associated with human activities for thousands of years, being the primary biological agent in baking, brewing, winemaking and other fermentation processes.
It is also one of the most important model organisms in molecular biology and genetics research. For a long time, the history and evolution of this important yeast has been a completely mystery, but recent advances in genome sequencing technologies now allow it to be studied in great detail.
Using next-generation sequencing, corresponding author Gianni Liti et. al. provide a detailed characterization of the genetic variation present within the baker's yeast species. They sequenced the genomes of 42 strains of S. cerevisiae and its closest relative S. paradoxus, which is an entirely wild species that has not had any contact with humans.
A central finding of this study is that even though strains in S. paradoxus are separated by much greater genetic distances in terms of single-nucleotide polymorphisms (SNPs), the S. cerevisiae strain genomes harbor more variation in terms of absence and presence and copy number of genes.
It has previously been observed that trait variation is also much larger in S. cerevisiae than in its wild relative. These new results therefore raise the intriguing hypothesis that this variation in the content of the genome, rather than single-nucleotide differences, underlies the large phenotypic variation in S. cerevisiae.
The authors find that the subtelomeric regions of the genomes, located just before the telomeres at each chromosome end, are highly enriched for genome variation that is likely to contribute to differences in traits between strains. This includes loss-of-function mutations that likely disrupt the function of whole genes. As an example of functional variation they describe how differences in the copy number of a subtelomeric gene cluster controls the ability of strains to grow under arsenic stress, and demonstrate that this variation is the product of convergent evolution in yeast lineages in different parts of the world.
"These genome sequences allowed us to expose surprising differences between the evolutionary histories of the common baker's yeast and its wild relative. Our results suggest that the very large diversity in traits observed between strains of baker's yeast might mostly be due to the presence or absence of entire genes rather than differences in single DNA letters."
The study provides intriguing insights into the recent history of this important organism and the relationship between genome variation and trait variation. Future research will further elucidate what role humans have played in shaping the evolution of baker's yeast, for example the extent to which the genomic variation is a consequence of yeast strains moving into novel habitats and niches opened up by human activities.
Joe Caspermeyer | EurekAlert!
Rice study decodes genetic circuitry for bacterial spore formation
24.05.2016 | Rice University
How Neural Circuits Implement Natural Vision
24.05.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau
In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...
Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices
Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.
When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene
In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...
The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.
Staphylococcus aureus usually is a formidable bacterial pathogen. Sometimes, however, weakened forms are found in the blood of patients. Researchers of the University of Würzburg have now identified one mutation responsible for that phenomenon.
Staphylococcus aureus is a bacterium that is frequently found on the human skin and in the nose where it usually behaves inconspicuously. However, once inside...
24.05.2016 | Event News
20.05.2016 | Event News
19.05.2016 | Event News
24.05.2016 | Earth Sciences
24.05.2016 | Information Technology
24.05.2016 | Materials Sciences