The research, published in the journal Current Biology tomorrow (26 January 2005), shows that an essential 'paternal effect' gene was created only recently in the evolutionary history of the fruit fly, Drosophila.
This finding is remarkable because it shows that new genes with new functions - including essential functions - can evolve at any time.
The researchers made the discovery as part of a project to produce the first molecular genetic characterisation of a paternal effect gene. Paternal effect genes are important because without them a fertilised egg cannot develop into an adult. Similar genes are most likely present in other animals, including humans.
Using molecular techniques, the researchers found that the Drosophila paternal effect gene they were characterising was only present in the melanogaster sub-group of fruit fly, but its progenitor, or ancestor, was present in all of the different sub-groups.
Using statistical information about the rate at which genes evolve, the researchers worked out that the gene was only about 1-2 million years old, and much younger than the majority of the genes in the remainder of the fruit fly genome.
This finding, that an essential gene has a relatively recent origin, overturns the conventional notion that genes with vital functions must have been created a long time ago, but raises important questions about why and how this particular gene evolved.
"This discovery really changes our concept of how new gene function can evolve, which is a major issue for evolutionary biology," said Dr Tim Karr from the University of Bath, who made the discovery with colleagues in the Centre de Genetique Moleculaire et Cellulaire in France and the University of
Contact: Andrew McLaughlin
University of Bath