Genomic and phenotypic evolution of Escherichia coli in a novel citrate-only resource environment

eLife

Alice Tillman¹  Tanush Jagdish²  Rohan Maddamsetti²  Jessica A Baxter³  Richard E Lenski³  Jeffrey E Barrick³  Nkrumah A Grant⁴  Zachary D Blount⁵  Joan L Slonczewski⁵  Sumaya T Ahmed⁵  Jeremy Moore⁵  Brooke A Sommerfeld⁶ 

[1] Program for Systems, Synthetic, and Quantitative Biology, Harvard University, Cambridge, United States;The BEACON Center for the Study of Evolution in Action, East Lansing, United States;Department of Biology, Kenyon College, Gambier, United States;Department of Biomedical Engineering, Duke University, Durham, United States;Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, United States;The BEACON Center for the Study of Evolution in Action, East Lansing, United States;

关键词: adaptation;    experimental evolution;    genomics;    gene amplification;    evolutionary innovation;    niche invasion;   

DOI  :  10.7554/eLife.55414

来源: DOAJ

【 摘 要 】

Evolutionary innovations allow populations to colonize new ecological niches. We previously reported that aerobic growth on citrate (Cit+) evolved in an Escherichia coli population during adaptation to a minimal glucose medium containing citrate (DM25). Cit+ variants can also grow in citrate-only medium (DM0), a novel environment for E. coli. To study adaptation to this niche, we founded two sets of Cit+ populations and evolved them for 2500 generations in DM0 or DM25. The evolved lineages acquired numerous parallel mutations, many mediated by transposable elements. Several also evolved amplifications of regions containing the maeA gene. Unexpectedly, some evolved populations and clones show apparent declines in fitness. We also found evidence of substantial cell death in Cit+ clones. Our results thus demonstrate rapid trait refinement and adaptation to the new citrate niche, while also suggesting a recalcitrant mismatch between E. coli physiology and growth on citrate.

【 授权许可】

Unknown