Meeting Abstract
Octocorals are predicted to dominate reefs under increasing environmental stress, largely due to their ability to better resist both abiotic and biotic stressors. In the fall of 2014, an unknown disease was observed affecting octocorals of the genus Eunicea on reefs near Florida’s coast. Signs of the disease were dark black appearance, indicative of heavily melanization of the tissue. To determine the immune response of these corals, fragments of healthy and infected colonies of Eunicea calyculata from the Florida coast were collected in fall of 2014 and analyzed using RNAseq analyses and biochemical immune assays. RNAseq data was analyzed for differential expression patterns using Cufflinks and co-expression groups were identified using the R package WGCNA. Differential expression analyses revealed that genes up regulated in diseased colonies were enriched for processes involved in adhesion and cell signaling, while downregulated genes were enriched for metabolic and transcriptional processes. Furthermore, WGCNA analyses identified one module of genes enriched in immune processes which was positively correlated to disease status, and a second module of genes, enriched in transcriptional and translational processes, which was negatively correlated to disease status. Together these findings not only provide insight into the immune response of E. calyculata, but also demonstrate a clear tradeoff between immune response and fitness of colonies that may have important ecological consequences.
