Meeting Abstract
20.6 Saturday, Jan. 4 14:45 Local adaptation in a Caribbean coral is associated with gene expression plasticity KENKEL, CD*; ALMANZA, AT; MATZ, MV; The University of Texas at Austin; The University of Texas at Austin; The University of Texas at Austin carly.kenkel@gmail.com
Understanding the mechanisms used by reef-building corals adapt to local conditions that vary in space can help refine predictions about how they will adapt in time to the effects of global climate change. In the Florida Keys, inshore patch reefs that are subject to high nutrient loads and thermal extremes host diverse coral communities, often with better cover than the more benign offshore reef tract. We preformed a reciprocal transplant of the mustard hill coral, Porites astreoides , between inshore and offshore reefs to test for local adaptation and identify the physiological mechanisms that enable this species to inhabit such disparate reef environments. Each reef site was represented by 15 colonies (genotypes), which were fragmented and outplanted at local and foreign sites. Following one year of transplantation coral energetic stores (total protein and lipid) and growth rates were significantly elevated in corals at their home reef site, consistent with local adaptation. Global gene expression profiling revealed significant differential expression in corals from different populations and in response to transplantation. Stress response genes were elevated in corals transplanted to the inshore reef site. Concomitantly, these genes were also constitutively up-regulated in inshore-origin corals, consistent with the front-loading hypothesis. Inshore-origin corals also appear to exhibit higher gene expression plasticity when transplanted to a novel environment than offshore corals, which may reflect acclimatization or adaptation to the environmental variability of their native reef site. Gene coexpression network analysis (WGCNA) revealed significant correlations between coregulated host gene groups and symbiont-related traits, which may reflect host regulation of intracellular symbiont populations.
