Contrasting effects of historical contingency on phenotypic and genomic trajectories during a two-step evolution experiment with bacteria
|Author(s)||Plucain Jessica1, 2, Suau Antonia1, 2, 3, Cruveiller Stephane4, 5, 6, Medigue Claudine4, 5, 6, Schneider Dominique1, 2, Le Gac Mickael1, 2, 7|
|Affiliation(s)||1 : Univ Grenoble Alpes, Lab Technol Ingn Med & Complex Informat Math & Ap, F-38000 Grenoble, France.
2 : CNRS, TIMC IMAG, F-38000 Grenoble, France.
3 : Conservatoire Natl Arts & Metiers, Paris, France.
4 : CEA, Direct Sci Vivant, Inst Genom, Genoscope, Evry, France.
5 : CNRS UMR8030, Evry, France.
6 : Lab Anal Bioinformat Genom & Metab, Evry, France.
7 : IFREMER, DYNECO Pelagos, F-29280 Plouzane, France.
|Source||Bmc Evolutionary Biology (1471-2148) (Biomed Central Ltd), 2016-04 , Vol. 16 , P. -|
|WOS© Times Cited||6|
|Keyword(s)||Experimental evolution, Escherichia coli, Adaptation, Historical contingency, Epistasis|
|Abstract||BackgroundThe impact of historical contingency, i.e. the past evolutionary history of a population, on further adaptation is mostly unknown at both the phenotypic and genomic levels. We addressed this question using a two-step evolution experiment. First, replicate populations of Escherichia coli were propagated in four different environmental conditions for 1000 generations. Then, all replicate populations were transferred and propagated for further 1000 generations to a single new environment.
ResultsUsing this two-step experimental evolution strategy, we investigated, at both the phenotypic and genomic levels, whether and how adaptation in the initial historical environments impacted evolutionary trajectories in a new environment. We showed that both the growth rate and fitness of the evolved populations obtained after the second step of evolution were contingent upon past evolutionary history. In contrast however, the genes that were modified during the second step of evolution were independent from the previous history of the populations.
ConclusionsOur work suggests that historical contingency affects phenotypic adaptation to a new environment. This was however not reflected at the genomic level implying complex relationships between environmental factors and the genotype-to-phenotype map.