Rebecca Satterwhite

Photo by the incomparable Dr. Tim Morton
hieeeee

I am a PhD candidate in my third year at UChicago. I use microbes and molecular genetic techniques to answer questions about how evolution works in light of ecology. I consider myself very fortunate to belong to the diverse & incredibly bright group of researchers known as Bergelson Lab.

My dissertation projects test the extent to which host ecology influences genome evolution and virulence in the plant-pathogen Pseudomonas syringae. I selected 6 host-pathogen pairs for which the pathogen was already genetically characterized, with hosts including crop cultivars as well as the model host Arabidopsis thaliana. First, I test for local adaptation in this system by measuring growth of each pathogen in its own & in each other’s native hosts. Second, I test whether each pathogen’s specific complement of accessory genes has adaptive potential by repeating the reciprocal inoculation described above with transposon mutant libraries of each pathogen. To create these libraries, I used transposon mutagenesis to knock-out function of each non-essential gene in each of the 6 pathogen genomes. I am now tracking changes in knock-out frequencies over the course of infection with targeted sequencing out of the transposon. The final, combined dataset will allow for mechanistic dissection of pathogenicity as it relates to gene content variation in this generalist pathogen species.

Previously, I worked with Dr. Tim Cooper at the University of houston to earn my M.S. and produce two publications: one on costs of adaptation in specialists vs generalists (Evolution 2015), and the other on epistasis between mutations along an adaptive trajectory (Nature Ecology and Evolution 2017).

Photo by fabulous field assistant Ellie Newman
Field collection 2017: using sterile technique out of the trunk of my car

Education

2021 Ph.D. (expected) Ecology and Evolution, University of Chicago. Advisor: Dr. Joy Bergelson. “Ecological adaptation & the genomic basis of pathogenicity in natural isolates of Pseudomonas syringae

2013 M.S. Biology, Ecology and Evolution track, University of Houston. Advisor: Dr. Tim Cooper. “Experimental evolution with Escherichia coli in diverse resource environments: Jacks of all trades become masters of none”

2011 B.A. English, minor in Biology, University of Houston. Advisor: Dr. Tony Frankino.

Publications

Wünsche, A., Dinh, D. M., Satterwhite, R. S., Arenas, C. D., Stoebel, D. M., & Cooper, T. F. (2017). Diminishing-returns epistasis decreases adaptability along an evolutionary trajectory. Nature Ecology & Evolution1, 0061. doi.org/10.1038/s41559-016-0061

Satterwhite, Rebecca and Tim F. Cooper. 2015. Constraints on adaptation of E. coli to mixed-resource environments increase over time. Evolutiondoi: 10.1111/evo.12710. 

University of Chicago, Dept. of Ecology & Evolution