In the movie Alien, the title character is an extraterrestrial creature that can survive brutal heat and resist the effects of toxins.
In real life, organisms with similar traits exist, such as the "extremophile" red alga Galdieria sulphuraria.
In hot springs in Yellowstone National Park, Galdieria uses energy from the sun to produce sugars through photosynthesis.
In the darkness of old mineshafts in drainage as caustic as battery acid, it feeds on bacteria and survives high concentrations of arsenic and heavy metals.
How has a one-celled alga acquired such flexibility and resilience?
To answer this question, an international research team led by Gerald Schoenknecht of Oklahoma State University and Andreas Weber and Martin Lercher of Heinrich-Heine-Universitat (Heinrich-Heine University) in Dusseldorf, Germany, decoded genetic information in Galdieria.
They are three of 18 co-authors of a paper on the findings published in this week's issue of the journal Science.
The scientists made an unexpected discovery: Galdieria's genome shows clear signs of borrowing genes from its neighbors.
Many genes that contribute to Galdieria's adaptations were not inherited from its ancestor red algae, but were acquired from bacteria or archaebacteria.
This "horizontal gene transfer" is typical for the evolution of bacteria, researchers say.
However, Galdieria is the first known organism with a nucleus (called a eukaryote) that has adapted to extreme environments based on horizontal gene transfer.
"The age of comparative genome sequencing began only slightly more than a decade ago, and revealed a new mechanism of evolution--horizontal gene transfer--that would not have been discovered any other way," says Matt Kane, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the r
|Contact: Cheryl Dybas|
National Science Foundation