RT Journal Article
SR Electronic
T1 Heritable variation in bleaching responses and its functional genomic basis in reef-building corals (<em>Orbicella faveolata</em>)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 185595
DO 10.1101/185595
A1 Katherine E. Dziedzic
A1 Holland Elder
A1 Eli Meyer
YR 2017
UL http://biorxiv.org/content/early/2017/09/10/185595.abstract
AB Reef-building corals are highly sensitive to rising ocean temperatures, and substantial adaptation will be required for animals and the ecosystems they support to persist in changing ocean conditions. Genetic variation that might support adaptive responses has been measured in larval stages of some corals, but these estimates remain unavailable for adult corals and the functional basis of this variation remains unclear. In this study, we focused on the potential for adaptation in Orbicella faveolata, a dominant reef-builder in the Caribbean. We conducted thermal stress experiments using corals collected from natural populations in Bocas del Toro, Panama, and then used multilocus SNP genotypes to estimate genetic relatedness among samples. This allowed us to estimate narrow-sense heritability of variation in bleaching responses, revealing that this variation was highly heritable (h2=0.89). This estimate suggests substantial potential for adaptive responses to warming by natural populations of O. faveolata in this region. To investigate the functional basis for this variation, we applied genomic and transcriptomic approaches enabled by growing sequence resources for this species. We used a genetic linkage map we’ve recently developed to map associations between SNP genotypes and bleaching responses, and identified two genetic markers associated with bleaching. We also profiled gene expression in corals with contrasting bleaching phenotypes, uncovering substantial variation in responses to thermal stress between heat-tolerant and heat-susceptible corals.Integrating these genomic and transcriptomic data with quantitative genetic analysis provides a new perspective on the mechanistic basis for thermal tolerance phenotypes and the potential for adaptation to rising ocean temperatures.