Figure 2

Corals exhibit a similar response to heat stress with and without deoxygenation. (a) Number (and percentage) of differentially expressed (DE) transcripts at FDR < 0.05 that were common to or unique between normoxic (H0) and deoxygenated (Hd) conditions when comparing heating temperatures (33 °C, 36 °C, 39 °C) to the baseline (30 °C). (b) Log₂-fold change (FC_log2) differences in gene expression of common heat stress genes under normoxic and deoxygenated heat stress. Considered DE transcripts are associated with calcium signalling, heat shock proteins, mitochondria, cytoskeletal restructuring, necrosis, glycolysis promotion, and ROS mitigation. Colour gradient indicates log₂-fold change, where green and yellow represent a positive and negative fold change, respectively. White space indicates no DE. Asterisks indicate those transcripts also reported under deoxygenation stress in coral^25,34. (c) Expression dynamics across temperatures for both conditions (H0 and Hd) for hypoxia-inducible factor alpha subunit (HIFα), prolyl hydroxylase domain 2/4 (EGLN1/P4HTM), HIFα inhibitor (HIFAN), and heat shock protein 90 (HSP90B1). Expression estimates are based on fragments per kilobase of transcript per million mapped reads (FPKM). Error bars denote standard error with n = 4 for each condition.