10.5061/DRYAD.8VJ725T
Wellband, Kyle
Université Laval
University of New Brunswick
Mérot, Claire
Université Laval
Linnansaari, Tommi
University of New Brunswick
Elliott, J. A. K.
Université Laval
Curry, R. Allen
University of New Brunswick
Bernatchez, Louis
Université Laval
Data from: Chromosomal fusion and life history-associated genomic
variation contribute to within-river local adaptation of Atlantic salmon
Dryad
dataset
2018
six6
structural variation
chromosomal fusion
Salmo salar
2018-11-20T10:09:13Z
2018-11-20T10:09:13Z
en
https://doi.org/10.1111/mec.14965
6137852 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Chromosomal inversions have been implicated in facilitating adaptation in
the face of high levels of gene flow, but whether chromosomal fusions also
have similar potential remains poorly understood. Atlantic salmon are
usually characterized by population structure at multiple spatial scales;
however, this is not the case for tributaries of the Miramichi River in
North America. To resolve genetic relationships between populations in
this system and the potential for known chromosomal fusions to contribute
to adaptation we genotyped 728 juvenile salmon using a 50K SNP array.
Consistent with previous work, we report extremely weak overall population
structuring (Global FST = 0.004) and failed to support hierarchical
structure between the river’s two main branches. We provide the first
genomic characterization of a previously described polymorphic fusion
between chromosomes 8 and 29. Fusion genomic characteristics included high
LD, reduced heterozygosity in the fused homokaryotes, and strong
divergence between the fused and the unfused rearrangement. Population
structure based on fusion karyotype was five times stronger than neutral
variation (FST = 0.019) and the frequency of the fusion was associated
with summer precipitation supporting a hypothesis that this rearrangement
may contribute local adaptation despite weak neutral differentiation.
Additionally, both outlier variation among populations and a polygenic
framework for characterizing adaptive variation in relation to climate
identified a 250 Kb region of chromosome 9, including the gene six6 that
has previously been linked to age-at-maturity and run-timing for this
species. Overall our results indicate that adaptive processes, independent
of major river branching, are more important than neutral processes for
structuring these populations.
Miramichi Ssal genotype dataZIP archive containing Miramichi River
Atlantic Salmon genotype data in binary PLINK v1.9 format (.BED, .BIM,
.FAM)CAST_2016_50K_all.zip