Horizontal gene transfer: Gene from bacteria lets beetle feed only on coffee beans
|February 29, 2012||Posted by News under horizontal gene transfer, News|
In “Bacterial gene helps coffee beetle get its fix” (Nature, February 27, 2012), Melissa Lee Phillips reports on a “Rare example of gene transfer that provides clear evolutionary benefit”:
A bacterial gene discovered in the genome of the coffee berry borer beetle, a major pest, seems to allow the beetle to occupy a unique ecological niche and feed exclusively on coffee beans.
Actually, beneficial gene transfers are being discovered all the time now, and may not in fact be rare. They may be a key way that evolution really happens (= not Darwinism):
Rose and his colleagues analysed the genome of the coffee berry borer beetle, Hypothenemus hampei, a small insect native to Africa that spread worldwide during the twentieth century. They identified a beetle gene, HhMAN1, that codes for a protein called mannanase, which breaks down the polysaccharide galactomannan — found in the coffee beans that the beetle feeds on. The gene closely resembles the sequence of a bacterial mannanase, and is the first gene of this type to be discovered in an insect.
Maybe not the last.
“Cases of ecologically significant HGT in eukaryotes are starting to pile up,” says Patrick Keeling, who studies the evolution of single-celled eukaryotes at the University of British Columbia in Vancouver.
Of course, if the beetle must live on coffee beans, this form of evolution could well be one road to the poorly understood process of extinction. Coffee is king of the lunch room now, so times must be good for the beetle. But will coffee always be king?
See also: Horizontal gene transfer? Sea slug incorporates algae’s chlorophyll factories
Whole chloroplasts move between species; how they do it unclear as yet – researchers
Ancient bacteria resisted antibiotics they’d never met – jumping genes implicated