Meeting Abstract

10.2  Friday, Jan. 4  Gene expression signatures of local adaptation in reef-building corals MATZ, MV*; KENKEL, CD; BAY, LK; Univ. of Texas at Austin; Univ. of Texas at Austin; Australian Institute of Marine Science matz@utexas.edu

The role of algal symbionts (Symbiodinium sp.) in adaptation of corals to local environmental conditions is well established, but little is known about the complementary mechanisms employed by the coral host. We present two experiments involving RNA-seq profiling of host gene expression in corals originating from different thermal environments. In the first experiment (Porites astreoides, Florida Keys), corals from inshore and offshore reefs were kept in common garden conditions involving long-term heat stress for 6 weeks. In the second experiment (Acropora millepora, Great Barrier Reef), corals were reciprocally transplanted between their native locations separated by about 1000 kilometers along the length of GBR, for 6 months. Two particularly interesting themes emerge from the functional analysis of hundreds of genes that were differentially regulated with respect to the site of origin or, in the second experiment, the site of outplanting. There is an effect on genes processing carbonate and bicarbonate ions and putatively involved in calcification. In addition, many genes involved in lipid transport and metabolism become regulated. It is tempting to speculate that these two apparently disparate functional modules might be linked through the regulation of proteins converting pyruvate to oxaloacetate, which was a strong signal observed in both experiments. There is, therefore, a possibility that corals might possess a central regulatory mechanism for physiological adaptation or acclimatization, similarly to what has been observed through ecological genomics studies in threespine stickleback fish (Gasterosteus aculeatus) and the Glanville fritillary butterfly (Melitaea cinxia).