Harvard researchers are unlocking the evolutionary secrets of one of the world's most recognizable groups of mushrooms, and to do it, they're using one of the most comprehensive fungal "family trees" ever created.
As reported in paper published July 18 in PLoS ONE, Associate Professor of Organismic and Evolutionary Biology Anne Pringle and Ben Wolfe, a Post-Doctoral Fellow in FAS Center for Systems Biology, studied the genetics of more 100 species of Amanita mushrooms about one-sixth of the genus' total diversity to create an elaborate phylogeny showing how each species is related to one another.
Arguably the most widely-recognized group of mushrooms in the world, Amanita mushrooms have appeared in popular culture ranging from Fantasia to the Super Mario Brothers video games. Though it includes a number of edible species, such as the Amanita caesarea, the group is probably best known for its many toxic species, including the death-cap mushroom.
Armed with their family tree, Pringle and Wolfe were able to determine that Amanita evolution has largely been away from species that help decompose organic material and toward those that live symbiotically on trees and their roots. More interestingly, they found that the transition came at a steep price the loss of the genes associated with breaking down cellulose.
"There had been earlier suggestions that this type of gene loss might be taking place, but our study is the first precise test of that hypothesis," Pringle said. "The idea makes sense if you're going to actively form a cooperative relationship with a tree, you probably shouldn't simultaneously be trying to break it apart and eat it. But it's a very tricky dance to form these kinds of tight, cooperative interactions, and I think this work shows there is a cost associated with that. You have to change, you have to commit, and it can become a sort of gilded cage these mushrooms are very successful, but they're
|Contact: Peter Reuell|