Evolthon: A community endeavor to evolve lab evolution.

Sivan Kaminski Strauss,Andras Solt,Emmanuel D Levy,Noa Aharon Hefetz,Alice Flint,Bálint Csörgő,Iftach Nachman,Ehud Sass,Elad Herz,Ning Yin,Michael M Desai,Aditya M Kunjapur,Michael Klutstein,Marc Rübsam,David G Wernick,Jeffrey E Gerst,Timothy M Wannier,Orna Dahan,Noah Jakimo,Yitzhak Pilpel,Roy Kishony,Olga Snitser,Idan Yelin,Thrasyvoulos Karydis,Deepa Agashe,Prashant Kumar,Omri Adini,Csaba Pál,Dvir Schirman,Daniel Schultz,Tanita Wein,Dor Russ,Yinon M Bar-On,Andreas Mershin,Sibylle C Vonesch,Shira Nouriel,Atray Dixit,Dmitry Zabezhinsky,Lars M Steinmetz,Aaron N Brooks,Dikla Levi,George M Church,Tal Dagan,Razi Zeidan,William F Mueller,Daniel Schraivogel,Nilima Walunjkar,Markus Ralser,Joseph M Georgeson,Ronen Hazan,Roni Rak,Bianca P Hennig,Katarzyna P Adamala,Shannon Johnson,Avihu H Yona,Ghil Jona,Rachel Soo Hoo Smith,Viridiana Olín-Sandoval ,Bede P Busby ,Alex N Nguyen Ba ,Timothy A Stiles ,Simmie L Foster ,Einat Shaer Tamar

doi:10.1371/journal.pbio.3000182

Abstract

In experimental evolution, scientists evolve organisms in the lab, typically by challenging them to new environmental conditions. How best to evolve a desired trait? Should the challenge be applied abruptly, gradually, periodically, sporadically? Should one apply chemical mutagenesis, and do strains with high innate mutation rate evolve faster? What are ideal population sizes of evolving populations? There are endless strategies, beyond those that can be exposed by individual labs. We therefore arranged a community challenge, Evolthon, in which students and scientists from different labs were asked to evolve Escherichia coli or Saccharomyces cerevisiae for an abiotic stress—low temperature. About 30 participants from around the world explored diverse environmental and genetic regimes of evolution. After a period of evolution in each lab, all strains of each species were competed with one another. In yeast, the most successful strategies were those that used mating, underscoring the importance of sex in evolution. In bacteria, the fittest strain used a strategy based on exploration of different mutation rates. Different strategies displayed variable levels of performance and stability across additional challenges and conditions. This study therefore uncovers principles of effective experimental evolutionary regimens and might prove useful also for biotechnological developments of new strains and for understanding natural strategies in evolutionary arms races between species. Evolthon constitutes a model for community-based scientific exploration that encourages creativity and cooperation.

Highlights

The known saying, “Nothing in biology makes sense except in light of evolution,” [1] clearly exemplifies the pivotal role of evolutionary thinking in biology
Some participants engineered genomes to introduce beneficial mutations at various levels of design, ranging from knock-in of genes induced as cold-resistance proteins, to random transformation of genomic DNA from coldresistant yeast strains
A noteworthy strategy is the daily-dilution routine performed at the desired condition, because it is the common strategy used in lab evolution experiments

Summary

Introduction

The known saying, “Nothing in biology makes sense except in light of evolution,” [1] clearly exemplifies the pivotal role of evolutionary thinking in biology.

Results

Conclusion