Contrasting transcriptome response to thermal stress in two key zooplankton species, Calanus finmarchicus and C. glacialis

• Published in: Marine Ecology Progress Series
• Main Authors: Smolina, Irina, Kollias, Spyros, Møller, Eva Friis, Lindeque, Penelope K., Sundaram, Arvind, Fernandes, Jorge, Hoarau, Galice
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: Arctic; Greenland; Arctic copepod; Calanus finmarchicus; Climate change; Disko Bay; Northeast Atlantic; Zooplankton
• Online Access: http://hdl.handle.net/10852/46090; http://urn.nb.no/URN:NBN:no-50289; https://doi.org/10.3354/meps11398

Climate change has already led to the range expansion of warm-water plankton assemblages in the northeast Atlantic and the corresponding range contraction of colder-water species. The temperate copepod Calanus finmarchicus is predicted to shift farther northward into polar waters traditionally dominated by the arctic copepod C. glacialis. To identify temperature-mediated changes in gene expression that may be critical for the thermal acclimation and resilience of the 2 Calanus spp., we conducted a whole transcriptome profiling using RNA-seq on an Ion Torrent platform. Transcriptome responses of C. finmarchicus and C. glacialis from Disko Bay, west Greenland, were investigated under realistic thermal stresses (at +5, +10 and +15°C) for 4 h and 6 d. C. finmarchicus showed a strong response to temperature and duration of stress, involving up-regulation of genes related to protein folding, transcription, translation and metabolism. In sharp contrast, C. glacialis displayed only low-magnitude changes in gene expression in response to temperature and duration of stress. Differences in the thermal responses of the 2 species, particularly the lack of thermal stress response in C. glacialis, are in line with laboratory and field observations and suggest a vulnerability of C. glacialis to climate change.