European sea bass genome and its variation provide insights into adaptation to euryhalinity and speciation

• Published in: Nature communications Vol. 5; no. 1; p. 5770
• Main Authors: Tine, Mbaye, Kuhl, Heiner, Gagnaire, Pierre-Alexandre, Louro, Bruno, Desmarais, Erick, Martins, Rute S.T., Hecht, Jochen, Knaust, Florian, Belkhir, Khalid, Klages, Sven, Dieterich, Roland, Stueber, Kurt, Piferrer, Francesc, Guinand, Bruno, Bierne, Nicolas, Volckaert, Filip A. M., Bargelloni, Luca, Power, Deborah M., Bonhomme, François, Canario, Adelino V. M., Reinhardt, Richard
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.12.2014; Nature Publishing Group; Nature Pub. Group
• Subjects: 631/181/457; 631/181/759; Adaptation, Physiological; Animals; Aquaculture; Atlantic Ocean; Bass - genetics; Bass - physiology; Biochemistry, Molecular Biology; Biodiversity; Biodiversity and Ecology; Chromosome Mapping; Environmental regulations; Environmental Sciences; Genetic Speciation; Genetic Variation; Genetics; Genome; Genomics; Humanities and Social Sciences; Life Sciences; Molecular Sequence Data; multidisciplinary; Phylogeny; Populations and Evolution; Science; Science (multidisciplinary); Speciation; Atlantic Ocean
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6770

The European sea bass ( Dicentrarchus labrax ) is a temperate-zone euryhaline teleost of prime importance for aquaculture and fisheries. This species is subdivided into two naturally hybridizing lineages, one inhabiting the north-eastern Atlantic Ocean and the other the Mediterranean and Black seas. Here we provide a high-quality chromosome-scale assembly of its genome that shows a high degree of synteny with the more highly derived teleosts. We find expansions of gene families specifically associated with ion and water regulation, highlighting adaptation to variation in salinity. We further generate a genome-wide variation map through RAD-sequencing of Atlantic and Mediterranean populations. We show that variation in local recombination rates strongly influences the genomic landscape of diversity within and differentiation between lineages. Comparing predictions of alternative demographic models to the joint allele-frequency spectrum indicates that genomic islands of differentiation between sea bass lineages were generated by varying rates of introgression across the genome following a period of geographical isolation. The European sea bass is an economically important fish species, which is subject to intense selective breeding. Here, the authors sequence the genome of the European sea bass and highlight gene family expansions underlying adaptation to salinity change, as well as the genomic architecture of speciation between two divergent sea bass lineages.