70K SNP array data for Lumpfish (Cyclopterus lumpus) across the trans-Atlantic

In marine species with large populations and high dispersal potential,
large-scale genetic differences and clinal trends in allele frequency can
provide insight into the evolutionary processes that shape diversity.
Lumpfish, Cyclopterus lumpus, is found throughout the North Atlantic and
has traditionally been harvested for roe and more recently used as a
cleaner fish in salmon aquaculture. We used a 70K SNP array to evaluate
trans-Atlantic differentiation, genetic structuring, and clinal variation
across the North Atlantic. Basin-scale structuring between the Northeast
and Northwest Atlantic was significant, with enrichment for loci
associated with developmental/mitochondrial function. We identified a
putative structural variant on chromosome 2, likely contributing to
differentiation between Northeast and Northwest Atlantic Lumpfish, and
consistent with post-glacial trans-Atlantic secondary contact. Redundancy
Analysis identified climate associations both in the Northeast (N = 1269
loci) and Northwest (N = 1637 loci), with 103 shared loci between them.
Clinal patterns in allele frequencies were observed in some loci (15% -
Northwest and 5% - Northeast) of which 708 loci were shared and involved
with growth, developmental processes, and locomotion. The combined
evidence of trans-Atlantic differentiation, environmental associations,
and clinal loci, suggests that both regional and large-scale
potentially-adaptive population structuring is present across the North
Atlantic.