Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E16
Höfundar / Authors: Axel Wilhelm Einarsson, Einar Árnason, Katrín Halldórsdóttir
Starfsvettvangur / Affiliations: University of Iceland
Kynnir / Presenter: Axel Wilhelm Einarsson
Chromosomal structural rearrangements such as inversions are large scale genomic mutations. Inversions suppress recombination in heterozygotes. If they combine adaptive gene complexes within their genomic islands of differentiation, they are often called supergenes. Such islands are known in the Atlantic cod, maintaining genomic divergence and ecotypes. Little is known about the related polar cod, although its panmictic distribution insinuates small if any, genomic diversity. However, there are strong indications for distinct populations, although genetic analyses have not been conclusive. Here we find genomic evidence for two inversions in a sample of polar cod from regions around Greenland at the exact chromosomal locations found in Atlantic cod. The inversions on linkage group 1 and 7 in the Atlantic cod, both linked to temperature adaptation, also seem to be present in the polar cod. A clear geographical separation of these different genotypes is not found, although there are signs of heterozygote deficiency in our sample, indicating the Wahlund effect or Dobzhansky-Muller hybridization incompatibility. The polar cod is a critical player in the Arctic food web, transferring a large share of energy from plankton to mammals and birds. With warming temperatures, cold-adapted gadid species such as the polar cod are under threat, as is the whole Arctic ecosystem. As the habitat of polar cod is already shrinking, these results may aid our understanding of polar cod future success or demise.