Widespread introgression in deep-sea hydrothermal vent mussels

BMC Evolutionary Biology

Research Article

Thorsten B. H. Reusch¹  Corinna Breusing²  Robert C. Vrijenhoek³ 

[1] GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105, Kiel, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105, Kiel, Germany;Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, 95039, Moss Landing, CA, USA;Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, 95039, Moss Landing, CA, USA;

关键词: Bathymodiolus;    Introgressive hybridization;    Hybrid zone models;    Single nucleotide polymorphisms;   

DOI  :  10.1186/s12862-016-0862-2

 received in 2016-11-07, accepted in 2016-12-21,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe analysis of hybrid zones is crucial for gaining a mechanistic understanding of the process of speciation and the maintenance of species boundaries. Hybrid zones have been studied intensively in terrestrial and shallow-water ecosystems, but very little is known about their occurrence in deep-sea environments. Here we used diagnostic, single nucleotide polymorphisms in combination with one mitochondrial gene to re-examine prior hypotheses about a contact zone involving deep-sea hydrothermal vent mussels, Bathymodiolus azoricus and B. puteoserpentis, living along the Mid-Atlantic Ridge.ResultsAdmixture was found to be asymmetric with respect to the parental species, while introgression was more widespread geographically than previously recognized. Admixed individuals with a majority of alleles from one of the parental species were most frequent in habitats corresponding to that species. Mussels found at a geographically intermediate vent field constituted a genetically mixed population that showed no evidence for hybrid incompatibilities, a finding that does not support a previously inferred tension zone model.ConclusionsOur analyses indicate that B. azoricus and B. puteoserpentis hybridize introgressively across a large geographic area without evidence for general hybrid incompatibilities. While these findings shed new light onto the genetic structure of this hybrid zone, many aspects about its nature still remain obscure. Our study sets a baseline for further research that should primarily focus on the acquisition of additional mussel samples and environmental data, a detailed exploration of vent areas and hidden populations as well as genomic analyses in both mussel hosts and their bacterial symbionts.

【 授权许可】

CC BY   
© The Author(s). 2017