Shedding light: nutritional and defensive interactions in ecologically important photosynthetic symbioses

This talk will be held in-person (WCPH classroom 460) and over Zoom at this link.

Symbioses between animals and microbes are widespread and have significant impacts on host physiology, ecosystem function, and evolution. In particular, symbiosis with photosynthetic organisms (“photosymbiosis”), like that between reef-building corals and Symbiodiniaceae dinoflagellate algae, allows hosts to dominate nutrient-poor tropical oceans worldwide. These algae form symbioses with other diverse, ecologically important marine animals including flatworms, sponges, and mollusks. My group’s main questions include: how do these very different host organisms interact on the cellular level with the same intracellular algal symbiont? What are the molecular mechanisms underlying these symbioses? To address this, we combine functional experimentation in old and new model systems, single-cell transcriptomics, metabolomics/lipidomics, and metabolic imaging.

Specifically in this talk, I will discuss recent work on two marine photosymbioses: cnidarians and acoel flatworms. We have previously used the model sea anemone Aiptasia and corals to reveal the importance of sterol lipid transfer from symbiont to host cnidarians. In my group, we are also establishing the acoel flatworm Waminoa as a new model for photosymbiosis. Using MALDI-mass spec imaging, we find that sterol transport also occurs in this symbiosis, and hypothesize this could be a common currency across photosymbioses. We are also applying single-cell RNA sequencing in the coral Acropora and flatworm Waminoa to understand and compare the molecular processes in symbiont-containing cells. Overall the aim of our work is to understand globally widespread and evolutionarily important photosymbioses and their response to environmental change.

Location: WCPH classroom 460

Zoom link (for virtual attendees): https://asu.zoom.us/j/82609477674?pwd=VW0xdlZKRjZWSWVDL1kyc21Id3RXZz09