Epistatic regulation of an adaptive phenotype increases population resilience to fluctuating environments
Year: 2025
Type: article
Abstract: Populations are locally adapted to their environment that can vary across space and across time. Understanding the genetic architecture of phenotypic variation that enable natural populations to track temporal changes of the environment is crucial in the context of the ongoing climate change. One successful example of ongoing climate adaptation is that of chemotype diversity in common thyme (Thymus vulgaris). Thyme harbors genetically determined individual chemotypes varying at a very local scale. Chemotypes can be grouped by their chemical composition into phenolic and non-phenolic ecotypes, which have been shown to be adapted to different local habitats. In recent years, ecotypes are shifting local frequency as they adaptively respond to ongoing climate change. To understand the genomic architecture of these phenotypes, we sequenced 1000 thyme individuals from over 50 sites spanning 9 gradients of altitude and environmental conditions across Southern France. Combining genetic, environmental and phenotypic data allowed us to catalogue and associate genetic and phenotypic diversity to environmental variation across local and regional spatial scales. Using a newly assembled genome, we mapped genetic variants determining chemotypes across populations. These include copy number variation at genes encoding terpene synthases in the biosynthesis of the monoterpenes that define the chemotypes. We characterize epistatic interactions across these loci and how this results in the maintenance of the two adaptive ecotypes. Finally, we use population genetic forward simulations to explore if and why the inferred epistatic and oligogenic genetic system provides an advantage over alternative genetic architectures for tracking environmental variation and climate change.
Authors: Garcia-Erill, Genís, Campuzano-Jiménez, Francisco, Gauthier, Perrine, Villesen, Palle, Faber, Andreas Havbro, Ørsted, Michael; id_orcid 0000-0001-8222-8399, Palmada-Flores, Marc, Santoni, Sylvain, Thompson, John D, Ehlers, Bodil Kirstine, Bataillon, Thomas
Institutions: Universitat de Girona, Aarhus University, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Institut Agro Montpellier, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7111527519
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