Browsing by Author "Reynes, Lauric"
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- Development of tools to rapidly identify cryptic species and characterize their genetic diversity in different European kelp speciesPublication . Mauger, Stéphane; Fouqueau, Louise; Avia, Komlan; Reynes, Lauric; Serrao, Ester; Neiva, J.; Valero, MyriamMarine ecosystems formed by kelp forests are severely threatened by global change and local coastline disturbances in many regions. In order to take appropriate conservation, mitigation, and restoration actions, it is crucial to identify the most diverse populations which could serve as a “reservoir” of genetic diversity. This requires the development of specifc tools, such as microsatellite markers to investigate the level and spatial distribution of genetic diversity. Here, we tested new polymorphic microsatellite loci from the genome of the kelp, Laminaria digitata, and tested them for cross-amplifcation and polymorphism in four closely related congeneric species (Laminaria hyperborea, Laminaria ochroleuca, Laminaria rodriguezii, and Laminaria pallida). Adding these 20 new microsatellite loci to the ten L. digitata loci previously developed by Billot et al. (Mol Ecol 7:1778-1780, 1998) and Brenan et al. (J R Soc Interface 11:1-12, 2014) and to the ten L. ochroleuca loci previ ously developed by Coelho et al. (Conserv Genet Resource 6:949-950, 2014), we retained a total of 30 polymorphic loci for L. digitata, 21 for L. hyperborea, 16 for L ochroleuca, 18 for L. rodriguezii, and 12 for L. pallida. These markers have been tested for the frst time in the last two species. As predicted, the proportion of markers that cross-amplifed between species decreased with increasing genetic distance. In addition, as problems of species identifcation were reported in this family, mainly between L. digitata and Hedophyllum nigripes, but also between L. digitata, L. hyperborea, and L. ochroleuca in areas where their range distributions overlap, we report a rapid PCR identifcation method based on species-specifc COI mitochondrial primers that allows these four species of kelp to be rapidly distinguished.
- Multi-generation dispersal shapes the genetic structure of the canopy-forming seaweed Ericaria amentacea syn. Cystoseira amentacea in the north-western Mediterranean SeaPublication . Reynes, Lauric; Legrand, Térence; Blanfuné, Aurélie; Assis, Jorge; Thibaut, Thierry; Bottin, LorraineCanopy-forming seaweeds, especially fucoids (Fucales, Phaeophyceae), constitute marine forests in the Mediterranean Sea that deliver key ecosystem services. However, escalating human pressures in coastal areas have led to habitat fragmentation, significantly impacting the dynamics of gene flow and evolutionary trajectories. In this study, we investigated population connectivity among 43 sites with Ericaria amentacea in the northwestern Mediterranean Sea. By integrating microsatellite genotyping and biophysical modelling, we aimed to evaluate the hypothesis that population connectivity is approximated by oceanographic connectivity, rather than coastal distance. While traditional approaches to oceanographic connectivity had focused on single-generation dispersal models, we adopted a multi-generation perspective. This involves employing a biophysical model that considers gene flow through multiple stepping-stone populations across the E. amentacea distribution and over distinct generations of dispersal. Using distance-based redundancy analysis (dbRDA), we found that multi-generation dispersal significantly contributes to genetic differentiation, surpassing the influence of coastal distance. Even so, genetic differentiation remained significant among all population pairs, suggesting that gene flow may be hindered by differential selection acting against migrants and/or obscured by the effects of local genetic drift. The latter is likely, given the species' low dispersal potential and self-compatibility, both of which promote small, spatially restricted breeding units. In addition, our results emphasized that oceanographic connectivity promoted long-distance dispersal across northern Corsica and Eastern Provence over a single generation through the drifting of fertile thalli, which might have contributed to moderate differentiation between local populations. Overall, this framework highlights the value of considering multi-generation dispersal across numerous intermediate stepping-stones for informing management strategies aimed at enhancing population connectivity and safeguarding genetic diversity in seaweeds.
- On the specific status of eastern mediterranean dendrophyllia corals (Cnidaria, Anthozoa): genetic characterization and speciation scenariosPublication . Aurelle, Didier; Haguenauer, Anne; Blaise, Chloé; Reynes, Lauric; Arnaud‐Haond, Sophie; Boavida, Joana; Cabau, Cédric; Klopp, Christophe; Lundalv, Tomas; Noûs, Camille; Sartoretto, Stéphane; Wienberg, Claudia; Jiménez, Carlos E.; Orejas, CovadongaThe deep-sea corals Dendrophyllia ramea and Dendrophyllia cornigera occur in Mediterranean and Atlantic waters. Both species are found in different environmental conditions, and they can colonize hard and soft substrates. These species then display an important ecological plasticity along with morphological plasticity. Nevertheless, there is a large knowledge gap on the genetic characteristics of the two species, including on the relationships between them and the possibility of cryptic species along their range. The recent discovery of Dendrophyllia populations off Cyprus in the eastern Mediterranean Sea raised new questions in this context. These corals were related to D. ramea but had some morphological differences with other known populations of this species. Here, we study the specific status of Dendrophyllia corals from Cyprus on the basis of morphology and genetics. The genetic data are interpreted by comparison with the same analysis performed on two Caryophyllia species. Both morphological and genetic data confirm that corals found off Cyprus belong to the D. ramea species. We further tested the speciation scenario using transcriptome data: the results indicate an absence of current gene flow between D. ramea and D. cornigera and that the divergence occurred more than 3 million years ago. We discuss the possible historical and ecological factors which may have shaped speciation in these species.