Cameron Currie, a UW-Madison researcher, has already impressed the scientific world with his detailed studies of ant species that raise fungus for food. He broke new ground with research that showed the ants produce bacteria that, in turn, produce an antibiotic used to kill parasites on their fungus farms.

Now Currie, microbial ecologist and evolutionary biologist, is pushing his research into yet another novel direction. He intends to sequence the genomes of the ants as well as their bacteria and fungus. It would be the first genomic level study of a community of organisms over evolutionary time.

The effort is also important because an understanding of such a relationship as it has evolved and changed may hold clues to how the ants found a way to do something we’re still struggling with — maintain the effectiveness of antibiotics as the pathogens they battle develop resistance.

The sequencing project will be conducted thanks to a major genomic sequencing grant from Roche Applied Science. Curry and UW-Madison’s Great Lakes Bioenergy Research Center, which is also part of the research project, were selected from 700 applicants.

Using Roche technology, Curry and other members of the team will sequence and study three ant genomes and 14 fungal and bacterial genomes associated with the ants.

The connections between the ants, their fungus farms and disease, or, more accurately, the lack of disease, in the fungus, has intrigued Currie from the beginning of his work. Either the disease was unique and not visible to us, Currie speculated, or the ants “have evolved incredible mechanisms to prevent disease.”

Fortunately, the latter proved to be the case. And that has opened up new worlds of research and posed myriad new questions.

First, there is important basic science to understand. By studying the genomes of different ant lineages, Currie may be able to bring the tools of modern-day science to bear on one of Darwin’s most interesting but little-explored ideas. In the “Origin of Species,” Darwin touched on the co-evolution of plant and animal communities and posited that such relationships were governed by intricate natural mechanisms rather than chance.

“When we look at the plants and bushes clothing an entangled bank,” wrote Darwin, “we are tempted to attribute their proportional numbers and kinds to what we call chance. But how false a view this is!”

Basically, we don’t evolve in isolation from all the life around us, though science has not looked deeply into this aspect of evolutionary change. Currie will be among the first scientists to look closely at how mutual interdependence influences evolution at the genetic level. He’ll do it by studying the ants and fungus and bacteria that live in the big, plastic boxes in his laboratory, his own version of Darwin’s “tangled bank.”

Though Currie is very taken by the basic science, he also points out that the information gleaned from the sequencing is likely to have practical benefits, too. For example, the bacteria used by the ants to grow and make their parasite-fighting antibiotic is the same kind of bacteria from which we have produced half the antibiotics now used in medicine. Already, Currie said, one antibiotic found by the researchers has passed an anti-cancer screen at Harvard.

So understanding the genetics of the bacteria holds out the promise of advances in our use of them to produce antibiotics.
Yet another likely benefit is in a field strangely removed from medicine. Currie and his team are also studying the enzymes the ants use to mulch the leaves they cut up and feed to the fungus. Perhaps, he said, there is something to be learned here that will expand our production of biofuels. After all, evolution has made these ant species into very efficient bio-processors over the last 50 million years.

Currie also said there is great educational value in the sequencing project. Students are fascinated by the ants and their fungus farms (think about the ant farm you had when you were a kid), and Currie is also putting together a plan that will eventually involve student scientists in the project. He hopes to provide high school science teachers with kits that will allow them to involve their students in helping to gather and analyze data from the sequenced genomes.
It all seems a lot to ask of the lowly ant.

But, then, maybe an ant that has figured out how to keep antibiotics working for 50 million years isn’t so lowly after all.