Population structure and geographic origin assignment of Mytilus galloprovincialis mussels using SNPs

Seafood traceability represents a major goal for regulators and fishing industries worldwide who seek to prevent commercial fraud, protect marine resources and ensure consumer safety. Genetic approaches can be used to trace the provenance of seafood based on the ability of DNA markers to assign samples back to their population of origin. Here, we have used thousands of genome-wide Single Nucleotide Polymorphism markers to provide a detailed genetic structure of the highly farmed Mediterranean mussel M. galloprovincialis in part of its native (Atlantic and Mediterranean areas) and introduced ranges (South-eastern Pacific area). Also, we have assessed the power of the newly developed markers to assign samples to their geographic origin. Results showed a clear differentiation between the Atlantic and the Mediterranean M. galloprovincialis populations, with significant differences also observed between the Mediterranean and South-eastern Pacific individuals. In addition, we found 90-100% of individuals could be correctly assigned to the Atlantic or Mediterranean/South-eastern Pacific populations when using only 10 to 25 SNPs. Our results support the possibility of the development of an accurate and cost-effective origin assignment tool with global uses in aquaculture management, seafood traceability and food safety.