Seminar: Dr. Mikhail Matz, University of Texas at Austin

Extent and evolutionary significance of heritable variation in reef-building corals (Host: Sara Davies)

Corals are excellent subjects for quantitative genetics: you can fragment the same colony into clonal replicates and expose them to various treatments, and generate thousands of offspring according to a desired crossing scheme to measure parental effects and even map quantitative trait loci. Our recent experiments along these lines brought several important insights. Individual colonies of the same coral species can differ by the expression of >25% of the genome, with up-regulated expression of hundreds of genes directly inherited by the offspring from their parents. Maternal effects vary but can influence thousands of genes, and are particularly prominent for energy-related traits such as oxidative metabolism. Other fitness-related physiological traits are also highly heritable: heat tolerance of coral larvae can vary up to ten-fold depending on the parents, and there is considerable variation in larval settlement, growth rate and disease susceptibility among coral genotypes. This variation represents raw material for natural selection, capable of fueling both local adaptation and evolution in response to climate change.