Large-scale mitochondrial COI gene sequence variability reflects the complex colonization history of the invasive soft-shell clam, Mya arenaria (L.) (Bivalvia)

• Published in: Estuarine, Coastal and Shelf Science
• Main Authors: Lasota, Rafal, Pierscieniak, Karolina, Garcia, Pascale, Simon-Bouhet, Benoit, Wolowicz, Maciej
• Other Authors: University of Gdansk, Institute of Oceanography-Department of Marie Ecosystem Functionning, LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Spread; Founder effect; Bottleneck effect; Introduction; mtDNA; Population genetics; [SDE]Environmental Sciences; White Sea
• Online Access: https://hal.archives-ouvertes.fr/hal-01548817; https://doi.org/10.1016/j.ecss.2016.08.033

International audience The aim of the study was to determine genetic diversity in the soft-shell clam Mya arenaria on a widegeographical scale using mtDNA COI gene sequences. Low levels of genetic diversity was found, whichcan most likely be explained by a bottleneck effect during Pleistocene glaciations and/or selection. Thegeographical genetic structuring of the studied populations was also very low. The star-like phylogeny ofthe haplotypes indicates a relatively recent, rapid population expansion following the glaciation periodand repeated expansion following the founder effect(s) after the initial introduction of the soft-shell clamto Europe. North American populations are characterized by the largest number of haplotypes, includingrare ones, as expected for native populations. Because of the founder effect connected with initial andrepeated expansion events, European populations have significantly lower numbers of haplotypes incomparison with those of North America. We also observed subtle differentiations among populationsfrom the North and Baltic seas. The recently founded soft-shell clam population in the Black Seaexhibited the highest genetic similarity to Baltic populations, which confirmed the hypothesis thatM. arenaria was introduced to the Gulf of Odessa from the Baltic Sea. The most enigmatic results wereobtained for populations from the White Sea, which were characterized by high genetic affinity withAmerican populations.