Genomic signatures of adaptation in invasive sea lamprey of the Laurentian Great Lakes

Background/Question/Methods

The sea lamprey (Petromyzon marinus) is a jawless fish that normally feeds as a parasite in the Atlantic Ocean, but spawns and rears in freshwater. In North America the species has become invasive and, by the late 1800s, had established freshwater-resident populations in Lake Ontario and the adjacent Finger Lakes (NY, USA). By the 1930s, construction of the Welland canal that bypasses Niagara Falls had allowed it to invade the other four Laurentian Great Lakes as well. Unlike anadromous sea lamprey, Great Lakes sea lamprey spend their entire lives in freshwater.

Results/Conclusions

Here we present our results from whole genome re-sequencing of 262 sea lamprey collected from the Great Lakes, Finger Lakes, and the North American anadromous population. The majority of sea lamprey captured in the Great Lakes area represent a single large population that originates from a recent genetic bottleneck. This freshwater population has evolved to be genetically distinct from the contemporary anadromous populations; there appears to be little or no genetic exchange between the two. Genomic scans for loci involved in local adaptation revealed an enrichment of genes involved in cell adhesion and synaptic signalling, among others. In my presentation I will explore evidence for selection on genes associated with physiological responses to lampricide and the potential utility of putatively adaptive loci for genetic control in the invasive population.