Plasmids, small independently replicating DNA segments found mostly in bacteria and archaebacteria, are molecular trucks, buses and taxicabs. Different plasmids can spread resistance against antibiotics, turn a benign bacterium into a virulent pathogen or degrade environmental contaminants.
By transferring genes among them, plasmids enable the ongoing evolution of these tiny and ever-present microbes.
Now, the National Science Foundation has awarded a grant of $1.1 million to a team of researchers from the University of Georgia to study how plasmids work in the bacterial world, especially on hosts important in agricultural, clinical or ecological processes.
“This is the first major grant awarded by any federal agency specifically for genomic studies of these ubiquitous mobile genetic elements,” said UGA microbiologist and team leader Anne Summers.
Others on the UGA team from the microbiology department include Tim Hoover, Jan Mrazek, Joy Peterson, Barny Whitman and Juergen Wiegel. Also on the team from the Franklin College of Arts and Sciences are Mary Ann Moran, marine sciences department, and Michael W. Adams, biochemistry and molecular biology department. Other colleagues include Margie Lee from the population medicine department in the College of Veterinary Medicine, and Timothy Denny, from the plant pathology department in the College of Agricultural and Environmental Sciences.
The new project will study plasmids isolated directly from freshly obtained and carefully preserved bacteria and archaebacteria. This is the first project to examine natural isolates in a wide range of such otherwise well-studied prokaryotes, the domain of organisms lacking a cell nuclear membrane.
“UGA is unique in the U.S., perhaps in the world, in having expertise in such a wide range of diverse prokaryotes as well as in plasmid biology,” said Summers.
Since this is the first such study that will examine these plasmids in freshly isolated prokaryotes, it could change the perceptions of these cellular components among those who study them. There’s another important aspect of the grant, too, according to Summers. “The project includes graduate and undergraduate components designed to give aspiring scientists an appreciation for the significance of horizontal gene transfer,” she said. “They will gain hands-on experience with both bench and computer analyses of these phenomena.”
Undergraduates from outside UGA also will join in all stages of the process during eight-week research projects available each summer during the three-year period of the award.