Transcriptomic analyses were undertaken on both in situ collected and experimentally warmed blue mussels (Mytilus edulis) from Greenland. M. edulis were collected from the Godthabsfjorden near Nuuk, Greenland (64.45555, -51.14416) at the following locations and dates: Inner fjord (64.45941, -50.31030) on 11/06/2018; outer fjord (64.19666, -51.69) on 13/06/2018, and sub-tidal (64.19666, -51.69) on 13/06/2018 (outer fjord at 20-40cm below the lowest low water mark). The in situ collected inner and outer fjord intertidal animals with outer fjord subtidal animals used as controls were collected at 27 degree Celsius, 19 degree Celsius and 3 degree Celsius, respectively. Some of the outer fjord subtidal M. edulis were experimentally warmed to 22 degree Celsius and 32 degree Celsius for one hour to mimic high aerial exposure temperatures in the inner and outer fjord intertidal, respectively. RNA-Seq was performed on 5 animals for each treatment, with all subsequent bioinformatics analyses performed by Novogene, China.

This work was supported by the Carlsberg Foundation, the Independent Research Fund Denmark (Danmarks Frie Forskningsfond) (DFF-International Postdoc; case no. 7027-00060B), a Marie Sklodowska-Curie Individual Fellowship (IF) under contract number 797387 and Aage V. Jensens Fond (Aage V. Jensens Foundation) and NERC-UKRI core funding to the British Antarctic Survey.