Transcriptome analysis reveals signature of adaptation to landscape fragmentation

Research output: Contribution to journalArticle

Abstract

We characterize allelic and gene expression variation between populations of the Glanville fritillary butterfly (Melitaea cinxia) from two fragmented and two continuous landscapes in northern Europe. The populations exhibit significant differences in their life history traits, e.g. butterflies from fragmented landscapes have higher flight metabolic rate and dispersal rate in the field, and higher larval growth rate, than butterflies from continuous landscapes. In fragmented landscapes, local populations are small and have a high risk of local extinction, and hence the long-term persistence at the landscape level is based on frequent re-colonization of vacant habitat patches, which is predicted to select for increased dispersal rate. Using RNA-seq data and a common garden experiment, we found that a large number of genes (1,841) were differentially expressed between the landscape types. Hexamerin genes, the expression of which has previously been shown to have high heritability and which correlate strongly with larval development time in the Glanville fritillary, had higher expression in fragmented than continuous landscapes. Genes that were more highly expressed in butterflies from newly-established than old local populations within a fragmented landscape were also more highly expressed, at the landscape level, in fragmented than continuous landscapes. This result suggests that recurrent extinctions and re-colonizations in fragmented landscapes select a for specific expression profile. Genes that were significantly up-regulated following an experimental flight treatment had higher basal expression in fragmented landscapes, indicating that these butterflies are genetically primed for frequent flight. Active flight causes oxidative stress, but butterflies from fragmented landscapes were more tolerant of hypoxia. We conclude that differences in gene expression between the landscape types reflect genomic adaptations to landscape fragmentation.

Details

Authors
  • Panu Somervuo
  • Jouni Kvist
  • Suvi Ikonen
  • Petri Auvinen
  • Lars Paulin
  • Patrik Koskinen
  • Liisa Holm
  • Minna Taipale
  • Anne Duplouy
  • Annukka Ruokolainen
  • Suvi Saarnio
  • Jukka Sireń
  • Jukka Kohonen
  • Jukka Corander
  • Mikko J. Frilander
  • Virpi Ahola
  • Ilkka Hanski
External organisations
  • University of Helsinki
  • Karolinska Institutet
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Genetics
Original languageEnglish
Article numbere101467
Number of pages12
JournalPLoS ONE
Volume9
Issue number7
Publication statusPublished - 2014 Jul 2
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes