It lives all around us and is probably one of the earliest domesticated organisms. Humans have been using it for tens of thousands of years. There is evidence that the Ancient Egyptians used it for baking and brewing and today yeast is regarded by geneticists, because of its genetic similarities to humans and the powerful tools available, as the ‘model’ model organism.
Domesticated yeast has been at the forefront of every major breakthrough in genomics. But has our long association with yeast made it too domesticated? Does the highly selected yeast we now produce for laboratory experiments in any way influence the outcome of scientific research?
After five years searching for the answer a team of scientists, led by Ed Louis at The University of Nottingham and Richard Durbin a principal investigator at The Sanger Institute, believe that even after centuries of domestication, the yeast we tamed for science, brewing and baking is actually much the same as its closest relatives still living in the wild.
Ed Louis, a professor of genome dynamics at the Institute of Genetics at The University of Nottingham, said: “We didn’t know much about the evolution of yeast and how much influence we had over the centuries by highly selecting for brewing, baking and laboratory experiments. We have established that yeast is, for example, more like cats than dogs in terms of their domestication. Like cats, and their relatives the lion and tiger, yeast is much more closely related than we thought and still looks and behaves in much the same way as its wild cousins. Therefore it remains to this day one of the best models even for evolutionary studies.”
Until now little has been known about the evolutionary processes taking place within populations and different strains of domesticated yeast. Scientists examined the genome sequencing of over 70 different strains of yeast. These are strains of Saccharomyces cerevisiae (S. cerevisiae) commonly used in the production of laboratory research, baking, wine making and the production of sake. They were compared with its closest relative, Saccharomyces paradoxus (S. paradoxus) isolates, found mainly on oak tree bark.
Their research, which has just been published in Nature, has established the level of variation between different populations and species of yeast. There is as much genetic variation between yeast strains as there is between humans. As a result of this research geneticists have been able to develop the model data set necessary for building tools for projects such as comparing thousands of human genomes. Yeast is a good model for studying cancer and ageing as well as diseases associated with specific cellular defects — such as diabetes and Alzheimer’s.
Dr Richard Durbin said: "We have been able to use the amazing power of modern DNA sequencing to obtain an unprecedented picture of the way the genes in this organism vary, and how it evolved. The tools we developed to study yeast are now being applied to the human genome, to help identify genetic variants that are involved in disease."
Dr Durbin will be visiting The University of Nottingham on Thursday February 12 2009 to give a lecture — Studying human genetic variation by whole genome sequencing — marking the 200th anniversary of the birth of Darwin.
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Notes to editors
: The University of Nottingham is ranked in the UK's Top 10 and the World's Top 100 universities by the Shanghai Jiao Tong (SJTU) and Times Higher (THE) World University Rankings.
More than 90 per cent of research at The University of Nottingham is of international quality, according to RAE 2008, with almost 60 per cent of all research defined as ‘world-leading’ or ‘internationally excellent’. Research Fortnight analysis of RAE 2008 ranks the University 7th in the UK by research power. In 27 subject areas, the University features in the UK Top Ten, with 14 of those in the Top Five.
The University provides innovative and top quality teaching, undertakes world-changing research, and attracts talented staff and students from 150 nations. Described by The Times as Britain's "only truly global university", it has invested continuously in award-winning campuses in the United Kingdom, China and Malaysia. Twice since 2003 its research and teaching academics have won Nobel Prizes. The University has won the Queen's Award for Enterprise in both 2006 (International Trade) and 2007 (Innovation — School of Pharmacy), and was named ‘Entrepreneurial University of the Year’ at the Times Higher Education Awards 2008.
The Wellcome Trust Sanger Institute, which receives the majority of its funding from the Wellcome Trust, was founded in 1992. The Institute is responsible for the completion of the sequence of approximately one-third of the human genome as well as genomes of model organisms and more than 90 pathogen genomes. In October 2006, new funding was awarded by the Wellcome Trust to exploit the wealth of genome data now available to answer important questions about health and disease. http://www.sanger.ac.uk
The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending around £650 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its impact on health and wellbeing.