The Project ‘New tools, methods, and resources for aquatic symbioses’, is funded by  the Gordon and Betty Moore Foundation via a Grant Agreement #9319 for Macquarie University (#9319) to B. Llorente.

Our lab is partner of a multidisciplinary, synergic team with complementary expertise in symbiosis, synthetic biology, evolutionary biology, and bioinformatics, as well as in the biology of cyanobacteria, D. discoideum, and S. cerevisiae. Specifically, the AIRE team is in charge of the evolutionary bioinformatic component of the grant.

In brief, this work tackles the issue of the evolution of photoendosymbiosis. Currently, the knowledge of primary photoendosymbioses remains very limited, in particular the complexity of the first steps of primary photoendosymbioses, which might be governed by principles that impose strong barriers to the establishment of stable interactions. Importantly, these first steps and their constraints are impossible to investigate using current approaches.

The primary barriers to understanding the early evolution of aquatic photosynthetic eukaryotes have been the inherent limitations of mainstream approaches to address cryptic processes of the distant past. Phylogenetics and phylogenomics have drawbacks associated with the erosion of phylogenetic signal and the loss and lateral transfer of genes, while current models already have a co-evolutionary history with a photosynthetic endosymbiont and, hence, they are limited in providing information about the early stages of photoendosymbiosis. To advance mechanistic understanding of primary photoendosymbioses, and thus to better decipher what happened in aquatic environments at the origins of Archaeplastida and Paulinella spp., this project will develop innovative models designed to catch the early steps of the process of photoendosymbiosis in action. We will harness synthetic biology approaches and highly experimentally tractable organisms to develop synthetic photoendosymbiosis models consisting of cyanobacteria living inside eukaryotic host cells, and use comparative analyses of molecular evolution to understand how this symbiosis evolves. In particular, the AIRE team will develop new tools to optimize the automated detection of key aspects of endosymbiosis, such as:

• Endosymbiotic gene transfers
• Gene creation and remodeling, via the detection of host-endosymbiont chimeric genes and rearrangements within the host and endosymbiont genomes
• Establishment of novel and rewired genetic interactions, involving the integration of host and endosymbiont biological processes