Replicated anthropogenic hybridisations reveal parallel patterns of admixture in marine mussels.
MetadataShow full item record
Simon, A., Arbiol, C., Nielsen, E. E., Couteau, J., Sussarellu, R., Burgeot, T., Bernard, I., et al. (2020). Replicated anthropogenic hybridisations reveal parallel patterns of admixture in marine mussels.. Evolutionary applications, 13 (3), 575-599. https://doi.org/10.1111/eva.12879
Human-mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in di erent places, they provide informally replicated experiments for studying hybridisation. We here examined 4279 Mytilus mussels, sampled in Europe and genotyped with 77 ancestry informative markers. We identi ed a type of introduced mussels, called ‘dock mussels’, associated with port habitats and displaying a particular genetic signal of admixture between M. edulis and the Mediterranean lineage of M. galloprovincialis. These mussels exhibit similarities in their ancestry compositions, regardless of the local native genetic backgrounds and the distance separating colonised ports. We observed ne-scale genetic shifts at the port entrance, at scales below natural dispersal distance. Such sharp clines do not fit with migration selection tension zone models, and instead suggest habitat choice and early stage adaptation to the port environment, possibly coupled with connectivity barriers. Variations in the spread and admixture patterns of dock mussels seem to be in uenced by the local native genetic backgrounds encountered. We next examined departures from the average admixture rate at different loci, and compared human-mediated admixture events, to naturally admixed populations and experimental crosses. When the same M. galloprovincialis background was involved, positive correlations in the departures of loci across locations were found; but when di erent backgrounds were involved, no or negative correlations were observed. While some observed positive correlations might be best explained by a shared history and saltatory colonisation, others are likely produced by parallel selective events. Altogether, genome-wide effect of admixture seems repeatable, and more dependent on genetic background than environmental context. Our results pave the way towards further genomic analyses of admixture, and monitoring of the spread of dock mussels both at large and ne spacial scales.
ANR Project HySea (ANR-12-BSV7-0011); Russian Science Foundation project N°19-74-2002.
Embargo Lift Date
External DOI: https://doi.org/10.1111/eva.12879
This record's URL: https://www.repository.cam.ac.uk/handle/1810/297522
All rights reserved