Editor's Summary
11 October 2007
A parting of the ways
Gene duplication has long been recognized as a source of new genes and functions, but most duplicated genes do not have new functions; they simply subdivide the tasks of the ancestral gene. An example of task division has now been analysed in detail. In the yeast Saccharomyces cerevisiae, the galactose utilization pathway includes two very similar genes, encoding a co-inducer (GAL3) and an enzyme (GAL1). The two are descended from a single bifunctional ancestral gene still found in other yeasts. Possible conflict between the two original genes has been resolved principally by a series of adaptive changes in regulatory sequences. The gradual degeneration took nearly 100 million years to complete, and was capped by Gal3's complete loss of galactokinase activity. GAL1 and GAL3 became integrated into a more complex and arguably more optimal genetic pathway.
News and Views: Evolutionary genetics: Making the most of redundancy
Single genes, chromosomal regions and even entire genomes can undergo duplication. What good can come of these extra copies? Evolution seems to use several tricks to take advantage of the situation.
Edward J. Louis
doi:10.1038/449673a
Article: Gene duplication and the adaptive evolution of a classic genetic switch
Chris Todd Hittinger & Sean B. Carroll
doi:10.1038/nature06151
Abstract | Full Text | PDF (3,943K) | Supplementary information