Herbarium manager tracks fern migration
OCTOBER 2011 - When herbarium collection manager Jordan Metzgar organized the Exploring the Fern Frontier symposium for the International Botanical Congress in Melbourne, Australia over the summer, he asked his colleague Mike Barker to participate.
The biological diversity specialist at the University of Arizona and his wife, Katrina Dlugosch, oversee labs stocked with next-generation sequencing equipment capable of turning out DNA data in amounts hundreds of times greater than previous technology allowed.
It turned out to be a good connection to reestablish.
Metzgar is working on his Ph.D. at UAF, focusing on the parsley fern (Cryptogramma). He’s reconstructing the migration patterns of two Alaskan species (C. acrostichoides, the American parsley fern, and C. sitchensis, the Sitka parsley fern) after the last ice age, work that requires detailed molecular data. As they were catching up, Barker mentioned the sophisticated equipment in his wife’s lab and invited him to visit.
“That email was a little awkward,” Metzgar said. “It was like, ‘Mike says it would be OK to use your equipment.’ But she was very receptive.”
Metzgar spent just under a week in Tucson doing the prep work, using restriction enzymes and chopping up the DNA from many different specimens to create one combined super-sample.
“I’m looking at the DNA sequences of different plants to discover diverse spots where the parsley fern may have sought refuge during the last ice age. These refugia weren’t glaciated and acted as lifeboats.”
The other alternative would be that the plant retreated to warmer climates in the south, but that’s not what Metzgar’s betting happened. “They are associated with glaciers and are one of the first plants to come in when a glacier recedes.”
It also makes sense that ferns are the plants he’s specializing in. “I was going on a hike one summer in Pennsylvania while I was an undergrad. We were looking for a great blue heron rookery I thought was in the area. My companions were pointing out different ferns. We saw 12 or 15 species that day. We never did find the rookery.”
But Metzgar found his passion. He graduated from Cornell and took a job in a botany lab at Duke University. There he helped a post-doc with a tree fern project. (Tree ferns are tropical species with trunk-like stems that grow up to 20 meters tall.) He also worked on some side projects of his own, including the taxonomy of nitrogen-fixing water ferns used as bio-fertilizer in rice paddies.
Since he’s been at UAF, Metzgar has completed a taxonomic study of the genus Cryptogramma. Now he’s waiting for the results of his DNA study which are expected around Thanksgiving. “It will be the largest genomic data set of any fern.”