Tidal heat pulses on a reef trigger a fine-tuned transcriptional response in corals to maintain homeostasis.

For reef-building corals, extreme stress exposure can result in loss of endosymbionts, leaving colonies bleached. However, corals in some habitats are commonly exposed to natural cycles of sub-bleaching stress, often leading to higher stress tolerance. We monitored transcription in the tabletop coral daily for 17 days over a strong tidal cycle that included extreme temperature spikes, and show that increases in temperature above 30.

Transcriptome-wide Changes in Coral Gene Expression at Noon and Midnight Under Field Conditions.

Reef-building corals experience high daily variation in their environment, food availability, and physiological activities such as calcification and photosynthesis by endosymbionts. On Ofu Island, American Samoa, we investigated day-night differences in gene expression under field conditions of changing pH, temperature, light, and oxygen. Using RNASeq techniques, we compared two replicate transcriptomes from a single coral colony of Acropora hyacinthus over six noons and five midnights.