A survey of genomes of multicellular organisms repeatedly turned up genetic material originating in bacteria. The new genes may provide immediate new functions. Steve Mirsky reports.
Bacteria commonly swap genes, even if the two tiny critters are only distantly related. For bacteria to throw some of their genes into multicellular organisms is considered rare—when bacterial genes are found in genome analysis, they’re often thought to be due to contaminated samples. But a report in the latest issue of the journal Science finds that what’s called “lateral gene transfer” may at times not be all that unusual.
The bacteria Wolbachia pipientis infects a wide range of organisms, including about 20 percent of all insect species. And it’s present in their egg cells. That puts it in a good position to send genes into its host’s next generation. So researchers examined various host genomes, looking for genes from Wolbachia. And they found four insect and four nematode species whose genomes included the bacterial genes. In fact, one Drosophila species’ genome had practically the entire Wolbachia genome in it. Such lateral gene transfer may be an evolutionary kickstart—the recipient species instantly gets a package of new genes with potential new functions.