Meeting Abstract
The Great Barrier Reef (GBR) extends across 15 degrees of latitude, corresponding to 3°C mean sea surface temperature difference between its northernmost and southernmost locations. Thermal gradients also exist within latitudes across the continental shelf, with inshore reefs experience up to 2oC higher midsummer temperatures than offshore reefs. Previous studies have shown that populations of the coral Acropora millepora exhibit differences in heat tolerance with respect to both latitudinal and cross-shelf (inshore-offshore) temperature gradients. However, no study to date has correlated genetic variation and gene expression across these temperature gradients. Here, we characterize population genomic signatures of selection in six A.millepora populations throughout the GBR, representing inshore and offshore locations, and examine the extent of gene expression divergence between coral populations from the warm low-latitude Wilkie Island and the cooler mid-GBR Orpheus Island. Our results highlight key physiological processes and regulatory mutations that may confer selective benefits on A. millepora populations, depending on the local thermal regime.
