Galdieria's heat tolerance seems to come from genes that exist in hundreds of copies in its genome, all descending from a single gene the alga copied millions of years ago from an archaebacterium.
"The results give us new insights into evolution," Schoenknecht says. "Before this, there was not much indication that eukaryotes acquire genes from bacteria."
The alga owes its ability to survive the toxic effects of such elements as mercury and arsenic to transport proteins and enzymes that originated in genes it swiped from bacteria.
It also copied genes offering tolerance to high salt concentrations, and an ability to make use of a wide variety of food sources. The genes were copied from bacteria that live in the same extreme environment as Galdieria.
"Why reinvent the wheel if you can copy it from your neighbor?" asks Lercher.
"It's usually assumed that organisms with a nucleus cannot copy genes from different species--that's why eukaryotes depend on sex to recombine their genomes.
"How has Galdieria managed to overcome this limitation? It's an exciting question."
What Galdieria did is "a dream come true for biotechnology," says Weber.
"Galdieria has acquired genes with interesting properties from different organisms, integrated them into a functional network and developed unique properties and adaptations."
In the future, genetic engineering may allow other algae to make use of the proteins that offer stress tolerance to Galdieria.
Such a development would be relevant to biofuel production, says Schoenknecht, as oil-producing algae don't yet have the ability to withstand the same extreme conditions as Galdieria.
|Contact: Cheryl Dybas|
National Science Foundation