Selection history and epistatic interactions impact dynamics of adaptation to novel environmental stresses Journal Article

Author(s): Lagator, Mato; Colegrave, Nick; Neve, Paul B
Article Title: Selection history and epistatic interactions impact dynamics of adaptation to novel environmental stresses
Affiliation IST Austria
Abstract: In rapidly changing environments, selection history may impact the dynamics of adaptation. Mutations selected in one environment may result in pleiotropic fitness trade-offs in subsequent novel environments, slowing the rates of adaptation. Epistatic interactions between mutations selected in sequential stressful environments may slow or accelerate subsequent rates of adaptation, depending on the nature of that interaction. We explored the dynamics of adaptation during sequential exposure to herbicides with different modes of action in Chlamydomonas reinhardtii. Evolution of resistance to two of the herbicides was largely independent of selection history. For carbetamide, previous adaptation to other herbicide modes of action positively impacted the likelihood of adaptation to this herbicide. Furthermore, while adaptation to all individual herbicides was associated with pleiotropic fitness costs in stress-free environments, we observed that accumulation of resistance mechanisms was accompanied by a reduction in overall fitness costs. We suggest that antagonistic epistasis may be a driving mechanism that enables populations to more readily adapt in novel environments. These findings highlight the potential for sequences of xenobiotics to facilitate the rapid evolution of multiple-drug and -pesticide resistance, as well as the potential for epistatic interactions between adaptive mutations to facilitate evolutionary rescue in rapidly changing environments.
Keywords: Epistasis; Adaptation; pleiotropy; Evolutionary rescue; environmental change; xenobiotics
Journal Title: Proceedings of the Royal Society of London Series B Biological Sciences
Volume: 281
Issue 1794
ISSN: 0962-8452
Publisher: Royal Society, The  
Date Published: 2014-09-17
Start Page: 20141679
Sponsor: The project was supported by Leverhulme Trust
DOI: 10.1098/rspb.2014.1679
Notes: We thank Tom Vogwill for helpful discussions, Carol Evered for technical assistance and Andrew Morgan for providing opinions and comments on the manuscript.
Open access: yes (repository)