Reduced thermal tolerance in a coral carrying CRISPR-induced mutations in the gene for a heat-shock transcription factor

Significance Coral reefs are biodiversity hotspots of great ecological, economic, and aesthetic importance. Their global decline due to climate change and other stressors has increased the urgency of understanding the molecular bases of corals’ responses to stress. Analyses of coral genomes and gene-expression patterns have identified many genes that may be important in stress resistance, but rigorous testing of their function will require the analysis of appropriate mutants. Here, we used CRISPR technology to show that mutational loss of a putative regulator of gene expression in response to heat stress indeed produced a loss of heat tolerance. Such use of CRISPR to generate mutations in corals should illuminate many aspects of coral biology and, thus, help to guide conservation efforts.