Local adaptation at the transcriptome level in brown trout: Evidence from early life history temperature genomic reaction norms

Kristian Meier, Michael Møller Hansen, Eric Normandeau, Karen-Lise Dons Mensberg, Jane Frydenberg, Peter Foged Larsen, Dorte Bekkevold, L. Bernatchez

Research output: Contribution to journalJournal articleResearchpeer-review

444 Downloads (Pure)

Abstract

Local adaptation and its underlying molecular basis has long been a key focus in evolutionary biology. There has recently been increased interest in the evolutionary role of plasticity and the molecular mechanisms underlying local adaptation. Using transcriptome analysis, we assessed differences in gene expression profiles for three brown trout (Salmo trutta) populations, one resident and two anadromous, experiencing different temperature regimes in the wild. The study was based on an F2 generation raised in a common garden setting. A previous study of the F1 generation revealed different reaction norms and significantly higher QST than FST among populations for two early life-history traits. In the present study we investigated if genomic reaction norm patterns were also present at the transcriptome level. Eggs from the three populations were incubated at two temperatures (5 and 8 degrees C) representing conditions encountered in the local environments. Global gene expression for fry at the stage of first feeding was analysed using a 32k cDNA microarray. The results revealed differences in gene expression between populations and temperatures and population × temperature interactions, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations. These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level of phenotypic plasticity at the transcriptome level. Our study demonstrates the usefulness of transcriptome approaches to identify genes with different temperature reaction norms. The responses observed suggest that populations may vary in their susceptibility to climate change.
Original languageEnglish
Article numbere85171
JournalPLOS ONE
Volume9
Issue number1
ISSN1932-6203
DOIs
Publication statusPublished - 2014

Fingerprint Dive into the research topics of 'Local adaptation at the transcriptome level in brown trout: Evidence from early life history temperature genomic reaction norms'. Together they form a unique fingerprint.

Cite this