title: Adaptive differentiation coincides with local bioclimatic conditions along an elevational cline in populations of a lichen-forming fungus.
abstract: Many fungal species occur across a variety of habitats. Particularly lichens, fungi forming symbioses with photosynthetic partners, have evolved remarkable tolerances for environmental extremes. Despite their ecological importance and ubiquity, little is known about the genetic basis of adaption in lichen populations. Here we studied patterns of genome-wide differentiation in the lichen-forming fungus Lasallia pustulata along an altitudinal gradient in the Mediterranean region. We resequenced six populations as pools and identified highly differentiated genomic regions. We then detected gene-environment correlations while controlling for shared population history and pooled sequencing bias, and performed ecophysiological experiments to assess fitness differences of individuals from different environments.
  
  
  
  We detected two strongly differentiated genetic clusters linked to Mediterranean and temperate-oceanic climate, and an admixture zone, which coincided with the transition between the two bioclimates. High altitude individuals showed ecophysiological adaptations to wetter and more shaded conditions. Highly differentiated genome regions contained a number of genes associated with stress response, local environmental adaptation, and sexual reproduction.
  
  
  
  Taken together our results provide evidence for a complex interplay between demographic history and spatially varying selection acting on a number of key biological processes, suggesting a scenario of ecological speciation.
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany. francesco.dalgrande@senckenberg.de.
authors.forename: Francesco
authors.initials: F
authors.lastname: Dal Grande
authors.affiliation: Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany.
authors.forename: Rahul
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.|Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany.
authors.forename: Anjuli
authors.initials: A
authors.lastname: Meiser
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Rolshausen
authors.affiliation: Plant Ecology and Systematics, Biology Department, University of Kaiserslautern, 67653, Kaiserslautern, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Büdel
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
authors.forename: Bagdevi
authors.initials: B
authors.lastname: Mishra
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Thines
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Otte
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.|Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Pfenninger
authors.affiliation: Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany. imke.schmitt@senckenberg.de.|Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany. imke.schmitt@senckenberg.de.
authors.forename: Imke
authors.initials: I
authors.lastname: Schmitt
mesh_terms: D000222:Adaptation, Physiological; D001203:Ascomycota / Q000145:classification / Q000235:genetics* / Q000502:physiology*; D017753:Ecosystem; D016681:Genome, Fungal; D023281:Genomics; D008011:Lichens / Q000145:classification / Q000235:genetics* / Q000502:physiology*; D019083:Mediterranean Region; D013559:Symbiosis
keywords: Adaptation; Altitudinal; Climate change; Fungi; Gradient; Pool-Seq; SNP; Symbiosis; ﻿Population genomics