Periodic Reporting for period 5 - SYMCELLS (Resolving the molecular mechanisms of intracellular coral-algal symbiosis)
Periodo di rendicontazione: 2022-06-01 al 2023-05-31
Research on coral symbiosis is also timely, since coral reefs are home to >25% of all marine species and provide food and income to millions of people. Thus coral reef ecosystems have major ecological and economic impacts for society. Yet, coral reefs are currently threatened by ‘coral bleaching’ due to climate change. Environmental stress such as the increase in sea water temperature leads to the breakdown of coral-algal symbiosis, which - if not reversed in a timely manner - leads to coral death. Understanding the molecular basis of the symbiotic interaction of corals and their symbionts provides the basis to understand the mechanisms of bleaching and thus the basis to develop effective means to mitigate coral reef loss.
Most corals acquire symbionts anew each generation during larval stages and the first objective of the project aims to uncover the fundamental mechanisms involved in symbiont acquisition and integration into host cells. Nutrient transfer from symbiont to host is vital to the survival of corals in nutrient poor environments and the second objective is to uncover key mechanisms of the metabolic transfer between the partners, as well as exploring the mechanisms of how symbionts can persist intracellularly inside host cells.
Along the way we also developed various new techniques, protocol and molecular tools to further establish Aiptasia as a model system for the cell biology, ecology and evolution of coral symbiosis. Specifically, we developed a protocol for microinjection to deliver mRNA, protein and DNA to Aiptasia larvae (Jones et al., Scientific Reports 2018), symbiont transformation (Gornik et al, Frontiers in Marine Science, 2022) and larval settlement to close the Aiptasia life cycle (Maegele et al., PNAS, in press). These methods are key to pave the way for a functional analysis of coral symbiosis looking at both partners, cnidarian host and dinoflagellate symbiont.
Finally, we engaged in some side projects during the course of SYMCELLS that are tangential to our analysis of symbiosis and cover the topic of the mechanisms of light sensing in symbiotic cnidarians and its function for adapting to challenging environments (Gornik et al., Molecular Biology and Evolution, 2020 and Kishimoto et al., Scientific Reports, in revision) and a comparative analysis on nutrient allocation in anemones, Garshall et al., bioRxiv doi: 10.1101/2023.05.15.540851).