The on-going climate change should have major impacts on the different components of biodiversity, from genes to ecosystems. Mediterranean marine species are already suffering from climate change, as shown by mortality events linked with thermal anomalies. This is especially true for cnidarians which have an important ecological role in Mediterranean benthic ecosystems and are attractive species for recreational scuba-diving. Among cnidarians the red coral,Corallium rubrum, also has a direct economical value. The main objective of the project is to understand the variability and evolution of adaptive abilities of the red coral to thermal stress. This species is present in very contrasted ecological conditions which correspond to genetically differentiated populations. Moreover, colonies from different regions, depths but also from the same site present thermotolerance differences. These differences might be linked to the individual history through acclimatization or to population level through genetic adaptation. During this PhD program, two complementary approaches will be developed to study these mechanisms:
i. Transcriptomic basis of thermotolerance differences : colonies from differents depths will be submitted to a common thermal stress in aquarium. The stress response will be evaluated just before necrosis using Illumina Next Generation Sequencing. This RNASeq procedure will allow identifying the components of the response to thermal stress in this species and to assess the variability of this response between individuals.
ii. Genomic study of local adaptation : we will look for genetic-environment associations through the identification of outlier loci with particular patterns of genetic differentiation. The RAD-sequencing (Restriction site Associated DNA sequencing) protocol will be applied here to characterize genetic polymorphism in a high number of independent loci.