Low incidence of clonality in cold water corals revealed through the novel use of standardized protocol adapted to deep sea sampling
|Author(s)||Becheler Ronan1, Cassone Anne-Laure1, Noel Philippe1, Mouchel Olivier1, Morrison Cheryl L.3, Arnaud-Haond Sophie1, 2|
|Affiliation(s)||1 : IFREMER, Ctr Brest, EEP LEP, Site Technopole, F-29480 Plouzane, France.
2 : IFREMER, Ctr Sete, UMR MARBEC, Bd Jean Monnet,BP 171, F-34203 Sete, France.
3 : US Geol Survey, Leetown Sci Ctr, Natl Fish Hlth Res Lab, 11649 Leetown Rd, Kearneysville, WV 25430 USA.
|Source||Deep-sea Research Part Ii-topical Studies In Oceanography (0967-0645) (Pergamon-elsevier Science Ltd), 2017-11 , Vol. 145 , P. 120-130|
|WOS© Times Cited||5|
|Keyword(s)||Cold-water coral, Lophelia pertusa, Madrepora oculata, Clonality, Fine-grained spatial genetic structure, Standardized sampling|
|Abstract||Sampling in the deep sea is a technical challenge, which has hindered the acquisition of robust datasets that are necessary to determine the fine-grained biological patterns and processes that may shape genetic diversity. Estimates of the extent of clonality in deep-sea species, despite the importance of clonality in shaping the local dynamics and evolutionary trajectories, have been largely obscured by such limitations. Cold-water coral reefs along European margins are formed mainly by two reef-building species, Lophelia pertusa and Madrepora oculata. Here we present a fine-grained analysis of the genotypic and genetic composition of reefs occurring in the Bay of Biscay, based on an innovative deep-sea sampling protocol. This strategy was designed to be standardized, random, and allowed the georeferencing of all sampled colonies. Clonal lineages discriminated through their Multi-Locus Genotypes (MLG) at 6 to 7 microsatellite markers could thus be mapped to assess the level of clonality and the spatial spread of clonal lineages. High values of clonal richness were observed for both species across all sites suggesting a limited occurrence of clonality, which likely originated through fragmentation. Additionally, spatial autocorrelation analysis underlined the possible occurrence of fine-grained genetic structure in several populations of both L. pertusa and M. oculata. The two cold-water coral species examined had contrasting patterns of connectivity among canyons, with among-canyon genetic structuring detected in M. oculata, whereas L. pertusa was panmictic at the canyon scale. This study exemplifies that a standardized, random and georeferenced sampling strategy, while challenging, can be applied in the deep sea, and associated benefits outlined here include improved estimates of fine grained patterns of clonality and dispersal that are comparable across sites and among species.|