Writing today in the journal Science, an international team led by University of Wisconsin-Madison bacteriologist Cameron Currie illustrates the intricate and ancient nature of this mutualistic relationship. The researchers found that the ants house the bacteria in specialized, highly adapted cavities and nourish them with glandular secretions-an indication that the ants, bacteria, fungus and parasites have likely been evolving together for tens of millions of years.
"Every ant species [that we have examined] has different, highly modified structures to support different types of bacteria," says Currie. "This indicates the ants have rapidly adapted to maintain the bacteria. It also indicates that the co-evolution between the bacteria and the ants, as well as the fungus and parasites, has been occurring since very early on, apparently for tens of millions of years."
Furthermore, Currie adds, the fact that the species have coexisted for so long means there might be a mechanism in place to decrease the rate of antibiotic resistance - which could help address a significant problem facing modern medicine. "We can learn a lot about our own use of antibiotics from this system," he says.
Currie studies the intricate relationships between certain species of ants in central and South America, the fungus they cultivate for food, the parasite that invades the fungus, and the bacteria that the ants harbor to fight the parasite. The phenomenon is a classic example of mutually beneficial symbiosis, and Currie views it as a model system with the potential to shed light on the way other organisms interact.
Although the ants and their fungus gardens had been closely studied for dozens of years, Currie was the first scientist to identify the crucial role of ba
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Contact: Cameron Currie
currie@bact.wisc.edu
708-435-0410
University of Wisconsin-Madison
5-Jan-2006