To determine the basis for the persistence of functional gene duplicates in the genome, three scientists at the Institute of Molecular Systems Biology at the Swiss Federal Institute of Technology in Zrich have collaborated on the largest systematic analysis of duplicated gene function to date. Using an integrative combination of computational and experimental approaches, they classified duplicate pairs of genes involved in yeast metabolism into four functional categories: (1) back-up, where a duplicate gene copy has acquired the ability to compensate in the absence of the other copy, (2) subfunctionalization, where a duplicate copy has evolved a completely new, non-overlapping function, (3) regulation, where the differential regulation of duplicates fine-tunes pathway usage, and (4) gene dosage, where the increased expression provided by the duplicate gene copy augments production of the corresponding protein.
Their results, which appear in the October issue of the journal Genome Research, indicate that no single role prevails but that all four of the mechanisms play a substantial role in maintaining duplicate genes in the genome.
"Our results contradict other recent publications that have focused on a single selective pressure as the basis for the retention of gene duplicates," explains Dr. Uwe Sauer, principal investigator on the project and Professor at the Institute of Molecular Systems Biology at the Swiss Federal Institute of
Contact: Maria A. Smit
Cold Spring Harbor Laboratory