My interests lie at the interface of ecology and evolution. How do the molecular and physiological pathways of organisms shape their ecology, and how does selection imposed by interactions with other organisms and the environment ultimately shape their genomes?
Current and planned projects include:
- The genomic basis of salinity adaptation in the model legume Medicago truncatula [see mt.usc.edu]
- The pan-genomic basis of nickel adaptation in wild Mesorhizobium
- Systems biology of cooperation and conflict in the legume-rhizobium symbiosis
- Structure and function of the Medicago microbiome
I grew up in rural British Columbia and attended the University of British Columbia in Vancouver, with an exchange year at McGill University in Montreal. I was part of “Science One”, an amazing first year science program that stressed the interdisciplinary nature of science. As a result, I had a hard time choosing my major—I wanted to quadruple major in math, biology, biochemistry, and english with a minor in physics. I ended up with a double major in Honours Math and Ecology, with several literature and writing courses and research experience in the evolution of polyploidy with Sally Otto, air quality modeling and environmental microbiology at the National Research Center of Canada, and experimental evolution of E. coli with Michael Doebeli.
I was a member of the Population Biology graduate group at UC Davis, having selected UCD as a school with both excellent quantitative biologists and a highly diverse taxonomic breadth of study organisms. During my first year Field Ecology course, Don Strong excavated a Lupinus nanus plant and showed me the brilliantly pink nodules formed by rhizobium bacteria. It was love at first sight. My dissertation consisted of (i) mathematical modeling of the interaction to determine whether multiply infected nodules gave rise to the evolution of cheaters [they can, but only under limited circumstances and the cheating is rarely absolute], (ii) a meta-analysis of rhizobia-legume fitness correlations [overall, they are strongly positive both across mutants and natural strains], and (iii) experimental evolution of Sinorhizobium meliloti on its host, the model legume Medicago truncatula. I selected the Medicago-Sinorhizobium interaction to focus on as it is one of the best-studied mutualistic plant-microbe interactions at the molecular level.
During my PhD, my advisor Sergey Nuzhdin and I wrote a NSF Plant Genome grant to study the genomic basis of adaptation and co-adaptation in natural populations of Medicago truncatula that occur on and off saline soils in Tunisia. Sergey moved to the University of Southern California and I joined him for my my post-doc, which was funded by this grant. I developed my bioinformatic skills, going from raw Illumina files all the way through statistical analysis and biological interpretation, collaborated on a phenotype database that involved developing the Natural Diversity module of Chado within the GMOD ecosystem, and did field work in both Tunisia and Portugal.
I start as an Assistant Professor of Plant Biology at Michigan State University in January 2013.
My other wordpress site is marenlfriesen.wordpress.com
Maren L. Friesen will be starting as an Assistant Professor in Plant Biology at MSU starting January 2013. This weblog will contain information about research and people in her lab, so check back soon!