Spatiotemporal microbial evolution on antibiotic landscapes.
A key aspect of bacterial survival is the ability to evolve while migrating across spatially varying environmental challenges. Laboratory experiments, however, often study evolution in well-mixed systems. Here, we introduce an experimental device, the microbial evolution and growth arena (MEGA)-plate, in which bacteria spread and evolved on a large antibiotic landscape (120 × 60 centimeters) that allowed visual observation of mutation and selection in a migrating bacterial front. While resistance increased consistently, multiple coexisting lineages diversified both phenotypically and genotypically. Analyzing mutants at and behind the propagating front, we found that evolution is not always led by the most resistant mutants; highly resistant mutants may be trapped behind more sensitive lineages. The MEGA-plate provides a versatile platform for studying microbial adaption and directly visualizing evolutionary dynamics.
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Michael
M
Baym
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Tami D
TD
Lieberman
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Eric D
ED
Kelsic
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Remy
R
Chait
Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
Rotem
R
Gross
Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
Idan
I
Yelin
Department of Systems Biology, Harvard Medical School, Boston, MA, USA. Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel. Faculty of Computer Science, Technion-Israel Institute of Technology, Haifa, Israel. rkishony@technion.ac.il.
Roy
R
Kishony
D000222:Adaptation, Physiological / Q000235:genetics*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics*; D002939:Ciprofloxacin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D019143:Evolution, Molecular; D005838:Genotype; D008826:Microbial Sensitivity Tests / Q000295:instrumentation*; D050296:Microbial Viability / Q000187:drug effects / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D012641:Selection, Genetic; D014295:Trimethoprim / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D014295:Trimethoprim