Guzinski, J.; Ruggeri, P.; Ballenghien, M.; Mauger, S.; Jacquemin, B.; Jollivet, C.; Coudret, J.; Jaugeon, L.; Destombe, C.; Valero, M. Seascape Genomics of the Sugar Kelp Saccharina latissima Along the North Eastern Atlantic Latitudinal Gradient. Genes2020, 11, 1503.
Guzinski, J.; Ruggeri, P.; Ballenghien, M.; Mauger, S.; Jacquemin, B.; Jollivet, C.; Coudret, J.; Jaugeon, L.; Destombe, C.; Valero, M. Seascape Genomics of the Sugar Kelp Saccharina latissima Along the North Eastern Atlantic Latitudinal Gradient. Genes 2020, 11, 1503.
Temperature is one of the most important range-limiting factors for many seaweeds. Driven by the recent climatic changes, rapid northward shifts of species’ distribution ranges can potentially modify the phylogeographic signature of Last Glacial Maximum such as increased genetic diversity at lower latitudes. To explore this question in detail in the kelp Saccharina latissima, we used microsatellites and double digest RAD-sequencing derived SNPs on S. latissima sporophytes sampled within 11 sites spanning the entire European Atlantic latitudinal range of this species. In addition, we checked for statistical correlation between genetic marker allele frequencies and three environmental proxies (sea surface temperature, salinity, and water turbidity). Our findings revealed that genetic diversity was significantly higher for the northern localities compared to the southern ones in contrast to the expected phylogeographic pattern. This suggests that the southernmost S. latissima populations are negatively affected by the recent climatic changes but also that the recolonization of S. latissima range following the LGM may have occurred from northerly refugia. Seven SNPs and 12 microsatellite alleles were found to be significantly associated with at least one of the three environmental variables. We discuss the potential adaptive functions of the genes associated with the outlier markers and the importance of these markers for successful conservation and aquaculture strategies for S. latissima in this age of rapid global change.
local adaptation; genetic diversity; outlier loci; environmental variables; phylogeography; SNPs and microsatellites
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