From the laboratory to the wild: salinity-based genetic differentiation of the European sea bass (Dicentrarchus labrax) using gene-associated and gene-independent microsatellite markers

TitleFrom the laboratory to the wild: salinity-based genetic differentiation of the European sea bass (Dicentrarchus labrax) using gene-associated and gene-independent microsatellite markers
Publication TypeJournal Article
Year of Publication2015
AuthorsGuinand, B, Quéré N, Desmarais E, Lagnel J, Tsigenopoulos CS, Bonhomme F
JournalMarine Biology
Volume162
Pages515-538
Abstract

Convincing evidence reporting adaptive variation
for physiologically and/or ecologically important traits
in marine taxa is often derived from studies comparing field
and laboratory observations and based on candidate-gene
markers, mainly allozymes, responding to habitat selection.
Likewise, patterns of genetic differentiation between
sea and lagoon populations of the euryhaline European sea
bass (Dicentrarchus labrax) were shown to correlate with
changes in allele frequencies recorded during experimental
salinity challenges, suggesting potential role for local adaptation. However, there has been criticism of these past
approaches, causing a need for further investigation. We
reinvestigated this correlation in European sea bass using
a set of 20 micro- and one minisatellite markers, some of
which are associated with candidate genes. We used rigorous
experimental settings to demonstrate that only one
single gene-associated marker consistently reported significant
genetic differentiation between fish raised in seawater
compared to fish acclimated to freshwater (locus EIF3E;
FST = 0.060; p = 0.007, n = 268). A few other loci were
shown to be false positive and did not respond to selection.
Furthermore, a field study of sea–lagoon differentiation
in wild European sea bass (n = 144) using the same
loci reported marginally significant genetic differentiation
at locus EIF3E (FST = 0.0114, p = 0.068). This locus was
identified as putatively under selection. Two other microsatellite
loci associated with genes (DLA0070 and DLA0060,
respectively) were found to significantly participate to sea–
lagoon differentiation and deviate from neutral expectation.
The evidence for sea–lagoon local adaptation in sea bass
remains faint if not highly elusive.

DOI10.1007/s00227-014-2602-8

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