New publication: Trans-oceanic genomic divergence of Atlantic cod ecotypes is associated with large inversions

By Paul R Berg1,2, Bastiaan Star1, Christophe Pampoulie3, Ian R. Bradbury4,5,6, Paul Bentzen6, Jeffrey A. Hutchings1,6,7, Sissel Jentoft1,8 and Kjetill S. Jakobsen1 in Heredity

Abstract

Chromosomal rearrangements such as inversions can play a crucial role in maintaining polymorphism underlying complex traits and contribute to the process of speciation. In Atlantic cod (Gadus morhua), inversions of several megabases have been identified that dominate genomic differentiation between migratory and nonmigratory ecotypes in the Northeast Atlantic. Here, we show that the same genomic regions display elevated divergence and contribute to ecotype divergence in the Northwest Atlantic as well. The occurrence of these inversions on both sides of the Atlantic Ocean reveals a common evolutionary origin, predating the >100 000-year-old trans-Atlantic separation of Atlantic cod. The long-term persistence of these inversions indicates that they are maintained by selection, possibly facilitated by coevolution of genes underlying complex traits. Our data suggest that migratory behaviour is derived from more stationary, ancestral ecotypes. Overall, we identify several large genomic regions—each containing hundreds of genes—likely involved in the maintenance of genomic divergence in Atlantic cod on both sides of the Atlantic Ocean.

 

Heredity advance online publication, 20 September 2017, pages 1-11.

Official journal of the Genetics Society

DOI: 10.1038/hdy.2017.54

Link to online publication here.

Link to pdf here

 

1Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Norway

2Centre for Molecular Medicine Norway, Faculty of Medicine, University of Oslo, Norway

3Marine and Freshwater Research Institute, Reykjavik, Iceland

4Department of Fisheries and Oceans, St John’s, Newfoundland, Canada

5Ocean Sciences Centre, Memorial University of Newfoundland, St John’s, Newfoundland, Canada

6Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada

7Institute of Marine Research, Flødevigen Marine Research Station, Norway

8Centre for Coastal Research, University of Agder, Kristiansand, Norway

Published Oct. 6, 2017 1:57 PM - Last modified Oct. 6, 2017 2:25 PM