Data from: Diagnostic gene expression biomarkers of coral thermal stress

Gene expression biomarkers can enable rapid assessment of physiological
conditions in situ, providing a valuable tool for reef managers interested
in linking organism physiology with large-scale climatic conditions. Here,
we assessed the ability of quantitative PCR (qPCR) based gene expression
biomarkers to evaluate (1) the immediate cellular stress response (CSR) of
Porites astreoides to incremental thermal stress and (2) the magnitude of
CSR and cellular homeostasis response (CHR) during a natural bleaching
event. Expression levels largely scaled with treatment temperature, with
the strongest responses occurring in heat shock proteins. This is the
first demonstration of a “tiered” CSR in a coral, where the magnitude of
expression change is proportional to stress intensity. Analysis of a
natural bleaching event revealed no signature of an acute CSR in normal or
bleached corals, indicating that the bleaching stressor(s) had abated by
the day of sampling. Another long-term stress CHR-based indicator assay
was significantly elevated in bleached corals; though assay values overall
were low, suggesting good prospects for recovery. This study represents
the first step in linking variation in gene expression biomarkers to
stress tolerance and bleaching thresholds in situ by quantifying the
severity of ongoing thermal stress and its accumulated long-term impacts.