loading page

Recent speciation and hybridization in Icelandic deep-sea isopods: an integrative approach using genomics and proteomics
  • +5
  • Eva Paulus,
  • Saskia Brix,
  • Annabelle Siebert,
  • Pedro Martínez Arbizu,
  • Sven Rossel,
  • Janna Peters,
  • Jörundur Svavarsson,
  • Martin Schwentner
Eva Paulus
University of Groningen
Author Profile
Saskia Brix
Senckenberg am Meer
Author Profile
Annabelle Siebert
Senckenberg am Meer
Author Profile
Pedro Martínez Arbizu
Senckenberg Research Institute
Author Profile
Sven Rossel
Senckenberg am Meer
Author Profile
Janna Peters
Senckenberg am Meer Deutsches Zentrum für Marine Biodiversitätsforschung
Author Profile
Jörundur Svavarsson
University of Iceland
Author Profile
Martin Schwentner
Naturhistorisches Museum Wien
Author Profile

Abstract

The 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 present in all species.

Peer review status:UNDER REVIEW

17 Mar 2021Submitted to Molecular Ecology
19 Mar 2021Assigned to Editor
19 Mar 2021Submission Checks Completed
06 Apr 2021Reviewer(s) Assigned