Percorrer por autor "Valero, M."
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- Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifoliaPublication . ARNAUD-HAOND, Sophie; Aires, T; Candeias, R.; Teixeira, S. J. L.; Duarte, C. M.; Valero, M.; A, SerrãoSuccessful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of alpha and beta diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions.
- Seascape genetic study on Laminaria digitata underscores the critical role of sampling schemesPublication . Fouqueau, L.; Reynes, L.; Tempera, F.; Bajjouk, T.; Blanfuné, A.; Chevalier, C.; Laurans, M.; Mauger, S.; Sourisseau, M.; Assis, Jorge; Lévêque, L.; Valero, M.Understanding connectivity patterns in endangered species living in fragmented habitats is fundamental to improve management and conservation actions. Such improvements can be particularly pressing at trailing edges where populations are facing the greatest challenges of climate change, and appear all the more crucial if the species is commercially harvested. Seascape genetics have been increasingly used to meet these needs. In this study, we examined connectivity patterns among 32 populations located at the southern range limit of the oarweed kelp Laminaria digitata. Our populations were sampled in a roughly continuous manner, with the distance between neighboring populations ranging from a few km to about a few hundreds. By genotyping 11 microsatellite markers, our aim was to (1) refine analyses of population structure, (2) test whether on-shelf islands are genetically more differentiated compared to mainland populations, (3) evaluate the relative importance of various abiotic conditions in shaping the genetic structure and (4) evaluate if the relative importance of each environmental factor varied according to sampling schemes. Our analyses revealed a positive relation between connectivity links and genetic diversity: populations with high levels of connectivity were genetically enriched while isolated populations showed signs of genetic erosion. The genetically impoverished populations corresponded to the southernmost populations as well as populations along the northern coast of Brittany (Locquirec, Saint-Malo Bay) and the northernmost population in Pas-de-Calais. By performing db-RDA on various sampling schemes, geographic distance appeared as the dominant factor influencing connectivity between populations separated by great distances, while hydrodynamic processes were the main factor when analyzing continuously distributed 42 populations.