Finding genes and pathways that underlie coral adaptation.

Marine heat waves are having unprecedented impacts on reef-building corals worldwide. Corals within the same species have different sensitivity to heat stress, and part of this variation is due to genetic adaptation. Finding coral genotypes that underpin heat adaptation would allow the identification of adapted populations so that reef managers could protect and promote the spread of these adapted populations. Seascape genomics identifies candidate adaptive genotypes by associating variation in genotype frequencies across a reef system with historical thermal conditions. CRISPR/Cas9-based gene editing could assess and validate the functional roles of putative adaptive genotypes, and validated genotypes could then be used in conservation. Mass coral bleaching is one of the clearest threats of climate change to the persistence of marine biodiversity. Despite the negative impacts of bleaching on coral health and survival, some corals may be able to rapidly adapt to warming ocean temperatures. Thus, a significant focus in coral research is identifying the genes and pathways underlying coral heat adaptation. Here, we review state-of-the-art methods that may enable the discovery of heat-adaptive loci in corals and identify four main knowledge gaps. To fill these gaps, we describe an experimental approach combining seascape genomics with CRISPR/Cas9 gene editing to discover and validate heat-adaptive loci. Finally, we discuss how information on adaptive genotypes could be used in coral reef conservation and management strategies. [ABSTRACT FROM AUTHOR]