| Summary: | In the context of the multidisciplinary European research programmes ACES (Atlantic Coral Ecosystem Study), which objective was to formulate recommendations for a future sustainable use of Europe’s deep-water coral margin, the present study aimed to map the genetic variability of deep-water coral ecosystems in the northeast Atlantic. Such an approach is important to preserve the long-term evolutionary potential of species and communities. Various molecular methods were used to assess the genetic diversity of deep-water corals, by focusing on Lophelia pertusa , the main reef-building species in the northeast Atlantic. Investigations at a high taxonomic level aimed to understand the evolutionary history of azooxanthellate corals by placing them within the evolutionary tree of the Order Scleractinia, using partial sequences of the mitrochondrial 16S ribosomal RNA encoding gene. The taxonomy of L. pertusa was consistent with morphological studies at the family level. However, the specimens collected from the eastern and western Atlantic were genetically highly differentiated. Madrepora oculata, another framework building coral in the northeast Atlantic, was found not to be correctly classified by morphological analysis. Intraspecific analyses were also undertaken for L. pertusa, using two complementary methods: DNA sequencing and microsatellite screening. L. pertusa individuals collected at ten different sampling sites, distributed along the European margin and in Scandinavian fjords, were sequenced for the ribosomal Internal Transcribed Spacer (ITS) 1 and 2 nuclear DNA regions, and for the mitochondrial Cytochrome c Oxidase subunit I gene (COI), and screened with ten specific microsatellites markers, developed for L. pertusa . The ITS sequence data indicated a strong genetic differentiation between different fjord populations, and suggested that these sites have been colonized, after the last glaciation period, through migrants originating from more closely related, continental margin populations. The ...
|
|---|