Experimental genomics of fitness in yeast
Graham Bell*
-Author Affiliations
Biology Department, McGill University, 1205 Avenue Docteur Penfield, Montreal, Quebec H3A 1B21, Canada
*graham.bell@mcgill.ca
Abstract
The set of single-gene deletions in yeast can be used to evaluate the effect of mutation on fitness over the whole genome. The measurement of growth in pure culture or relative growth in mixtures has confirmed that most deletions have little effect in laboratory culture. Moreover, there is a sharp distinction between lethality and a very mild impairment of growth, with very few intermediate cases. Different components of fitness, such as growth rate and yield, are positively correlated. Growth is also positively correlated across environments, although new conditions of growth usually identify a few conditionally impaired strains. Double mutants on average show alleviating epistasis, although a few per cent of combinations are synthetic lethal. The properties of the yeast deletion set provide us with the first genome-wide account of fitness, although transferring these conclusions to the field is a task for the future.
gene deletion fitness components epistasis environmental heterogeneity plasticity
Footnotes
Invited review by the former president of the Canadian Society for Ecology and Evolution.
Received November 18, 2009.
Accepted January 12, 2010.
© 2010 The Royal Society
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