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Sergey Kryazhimskiy


We are interested in uncovering general principles of how mutations affect phenotypes at multiple levels of biological organization (gene expression, metabolic fluxes, etc.), and how these effects combine to determine organism’s fitness across environments. We approach this problem using experiments in model microorganisms S. cerevisiae and E.coli and mathematical modeling.

Our lab has three complementary themes. First, we empirically characterize how the effects of hundreds of mutations on fitness depend on the external environment and on the genetic background of the organism. In technical terms, we characterize the statistics of epistasis and pleiotropy. Second, we attempt to predict from first principles how mutations are expected to perturb cellular physiology and fitness. Third, we measure some of these mutational perturbations of cell physiology (e.g., changes in gene expression profiles) and test our theoretical predictions.


  • Neverov AD, Kryazhimskiy S, Plotkin JB, Bazykin GA (2015). Coordinated evolution of influenza A surface proteins. PLoS Genetics 11: e1005404 (PMID: 26247472)
  • Baym M, Kryazhimskiy S, Lieberman T, Chung H, Desai MM, Kishony R (2015). Inexpensive multiplexed library preparation for megabase-sized genomes. PLoS One 10: e0128036 (PMID: 26000737)
  • Kryazhimskiy S, Rice DP, Jerison ER, Desai MM (2014). Global epistasis makes adaptation predictable despite sequence-level stochasticity. Science 344: 1519–1522 (PMID: 24970088)
  • Kryazhimskiy S, Rice DP, Desai MM (2012). Population subdivision and adaptation in asexual populations of Saccharomyces cerevisiae. Evolution 66: 1931–1941 (PMID: 22671557)
  • Kryazhimskiy S, Tkačik G, Plotkin JB (2009). The dynamics of adaptation on correlated fitness landscapes. Proc Natl Acad Sci USA 106: 18638–18643 (PMID: 19858497)


Sergey Kryazhimskiy received his Ph.D. from Princeton University in 2008.

He did his postdoctoral work at the University of Pennsylvania and Harvard University where he was awarded the Burroughs Wellcome Fund Career Award at Scientific Interface. He will join the EBE faculty in January 2016.