Recent speciation and hybridization in Icelandic deep-sea isopods: An integrative approach using genomics and proteomics.

• Main Authors: Brix, Saskia, Paulus, Eva, Martinez Arbizu, Pedro, Rossel, Sven, Peters, Janna, Schwentner, Martin
• Format: Dataset
• Language: unknown
• Published: 2022
• Subjects: Haploniscus bicuspis; Haploniscidae; Asellota; Isopoda; proteomics; Greenland; Iceland
• Online Access: https://zenodo.org/record/6015252; https://doi.org/10.5061/dryad.r2280gbcd

The crustacean marine isopod species Haploniscus bicuspis (G.O. Sars, 1877) shows circum-Icelandic distribution in a wide range of environmental conditions and along well-known geographic barriers, such as the Greenland-Iceland-Faroe (GIF) Ridge. We wanted to explore population genetics, phylogeography and cryptic speciation as well as to investigate whether previously described, but unaccepted subspecies have any merit. Using the same set of specimens, we combined mitochondrial COI sequences, thousands of nuclear loci (ddRAD), and proteomic profiles, plus selected morphological characters using Confocal Laser Scanning Microscopy (CLSM). Five divergent genetic lineages were identified by COI and ddRAD, two south and three north of the GIF Ridge. Assignment of populations to the three northern lineages varied and detailed analyses revealed hybridization and gene flow between them, suggesting a single northern species with a complex phylogeographic history. No apparent hybridization was observed among lineages south of the Ridge, inferring the existence of two more species. Differences in proteomic profiles between the three putative species were minimal, implying an ongoing or recent speciation process. Population differentiation was high, even among closely associated populations, and higher in mitochondrial COI than nuclear ddRAD loci. Gene flow is apparently male-biased, leading to hybrid zones and instances of complete exchange of the local nuclear genome through immigrating males. This study did not confirm the existence of subspecies defined by male characters, which probably characterize different male developmental stages. The files MetaDataxlsx.xlsx and Hellinger_Matrix.csv refer to the proteomic data. All other data belong to the ddRAD. Funding provided by: German Science Foundation (DFG)*Crossref Funder Registry ID: Award Number: BR3843/4-1,5-1 and MerMet17-06 (This work was also supported by the DFG initiative 1991 'Taxon-omics' [grant number RE2808/3-1 and RE2808/3-2].) All H. bicuspis specimens ...