Symbiotic associations enable organisms to adopt new ecological roles. Using the anemone model Aiptasia, we dissect the mechanisms, ecology and evolution underlying coral-algal endosymbiosis to learn how molecular interactions between distinct species lead to stable and complex ecosystems, which have co-evolved over millions of years.
Symbiotic associations occur in all domains of life and are key drivers of adaption and evolutionary diversification. A prime example is the endosymbiosis between corals and eukaryotic, photosynthetic dinoflagellates which transfer critical nutrients to their coral host. Here, two very distinct cells, an animal host and a dinoflagellate symbiont cell, coordinate their functions to drive the productivity and biodiversity of a whole ecosystem. This highlights the need for cell biology of endosymbiosis. This is challenging because corals are difficult experimental subjects. To make this possible we apply a unique model systems’ approach using the symbiosis anemone model Aiptasia, modern organismal biology, cell biology, biochemistry, and comparative work with phylogenetically relevant organisms at the bench and corals in the field. Dissecting the cell biology of this endosymbiotic life-style at the mechanistic level is critical to understand its evolution and response to the environment. Research on coral symbiosis is also timely, since coral reefs are home to >25% of all marine species and currently threatened by ‘coral bleaching’ due to climate change.