Biochemical Genetics

, Volume 50, Issue 5, pp 454–466

Differences in Salinity Tolerance and Gene Expression Between Two Populations of Atlantic Cod (Gadus morhua) in Response to Salinity Stress

  • P. F. Larsen
  • E. E. Nielsen
  • K. Meier
  • P. A. Olsvik
  • M. M. Hansen
  • V. Loeschcke
Article

DOI: 10.1007/s10528-011-9490-0

Cite this article as:
Larsen, P.F., Nielsen, E.E., Meier, K. et al. Biochem Genet (2012) 50: 454. doi:10.1007/s10528-011-9490-0

Abstract

Populations of marine fish, even from contrasting habitats, generally show low genetic differentiation at neutral genetic markers. Nevertheless, there is increasing evidence for differences in gene expression among populations that may be ascribed to adaptive divergence. Studying variation in salinity tolerance and gene expression among Atlantic cod (Gadus morhua) from two populations distributed across a steep salinity gradient, we observed high mortality (45% North Sea cod and 80% Baltic Sea cod) in a reciprocal common garden setup. Quantitative RT-PCR assays for expression of hsp70 and Na/K-ATPase α genes demonstrated significant differences in gene regulation within and between populations and treatment groups despite low sample sizes. Most interesting are the significant differences observed in expression of the Na/K-ATPase α gene in gill tissue between North Sea and Baltic cod. The findings strongly suggest that Atlantic cod are adapted to local saline conditions, despite relatively low levels of neutral genetic divergence between populations.

Keywords

Gene expression variationPopulation structureSalinity gradientSalinity tolerance

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • P. F. Larsen
    • 1
    • 2
  • E. E. Nielsen
    • 2
  • K. Meier
    • 2
  • P. A. Olsvik
    • 3
  • M. M. Hansen
    • 1
  • V. Loeschcke
    • 1
  1. 1.Department of Biological SciencesAarhus UniversityAarhus CDenmark
  2. 2.National Institute of Aquatic Resources, Technical University of DenmarkSilkeborgDenmark
  3. 3.National Institute of Nutrition and Seafood ResearchNordnes, BergenNorway