Molecular genetic differentiation of native populations of Mediterranean blue mussels, Mytilus galloprovincialis Lamarck, 1819, and the relationship with environmental variables

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The role of plasticity-related functional reorganization in the explanation of central dyslexias

The genetic constitution of mussels (<i>Mytilus</i> spp.) was studied by means of three nuclear (Me 15/16, EF-bis, ITS) and one mtDNA (ND2-COIII) marker on a large European scale. In addition to a sharp cline between Atlantic and Mediterranean <i>M. galloprovincialis</i>, we observed a clear genetic distinction between the Black Sea and Mediterranean populations and a higher incidence of <i>M. trossulus</i> than reported so far in northern European populations. The frequency of <i>M. galloprovincialis</i> nuclear alleles was high along the Iberian Peninsula and decreased abruptly along the French coasts with a high frequency of <i>M. edulis</i> alleles in the Bay of Biscay, The Netherlands, Germany, Iceland, Barents and White Seas, and with little evidence of introgression between the two taxa. <i>M. trossulus</i> alleles were observed in the Baltic Sea and Danish Straits as expected. In addition, occurrence of <i>M. trossulus</i> alleles in cold waters of Iceland, Barents Sea and White Sea is reported for the first time

The re-appearance of the Mytilus spp. complex in Svalbard, Arctic, during the Holocene: The case for an arrival by anthropogenic flotsam

The blue mussel Mytilus spp. complex has re-appeared in the high Arctic in Svalbard after a thousand years, with the first recent indication of its appearance in 2002 at the mouth of Isfjorden on the west coast. We examine its genetic affinity to selected North Atlantic populations and the modes of spread that may be responsible for its recent re-colonisation. We record here its distribution on Svalbard archipelago along the north-western coastline and within Isfjorden collected over a seven years period. We record for the first time the intertidal occurrence that includes a presence close to a glacier front. Genetic composition of mussels Mytilus spp. from different Svalbard locations reveal similarities mainly with populations of M. edulis, M. trossulus and their hybrid from Western Europe, Faroe Island, Scotland and Norway. The re-introduction to Svalbard most probably involved shipping and natural or anthropogenic flotsam. It seems that a new transport vector - large plastic debris - plays a significant role in this process