Moises Bernal
Nathan Backenstose
Daniel Yule
Trevor J. Krabbenhoft
Katherine Eaton
2021
<p><span>Local adaptation can drive diversification of closely related species across environmental gradients and promote convergence of distantly related taxa that experience similar conditions. We examined a potential case of adaptation to novel visual environments in a species flock (Great Lakes salmonids, genus </span><i>Coregonus</i><span>) using a new amplicon genotyping protocol on the Oxford Nanopore Flongle and MinION. We sequenced five visual opsin genes for individuals of </span><i>C. artedi</i><span>, </span><i>C. hoyi</i><span>, </span><i>C. kiyi</i><span>, and </span><i>C. zenithicus.</i><span> Comparisons revealed species-specific differences in a key spectral tuning amino acid in </span><i>rhodopsin</i><span> (Tyr261Phe substitution), suggesting local adaptation of </span><i>C. kiyi</i><span> to the blue-shifted depths of Lake Superior. Ancestral state reconstruction demonstrates that parallel evolution and “toggling” at this amino acid residue has occurred several times across the fish tree of life, resulting in identical changes to the visual systems of distantly related taxa across replicated environmental gradients. Our results suggest that ecological differences and local adaptation to distinct visual environments are strong drivers of both evolutionary parallelism and diversification.</span></p>
application/pdf
10.1093/gbe/evaa237
en
Oxford University Press
Nanopore amplicon sequencing reveals molecular convergence and local adaptation of rhodopsin in Great Lakes salmonids
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