Please find the symposium program at this link
Keynote Address: The archaeal roots of eukaryotic life
A public talk by Dr. Brett J. Baker
Friday, April 11th 2025, 4-5 PM in G10 Macdonald-Harrington Building
McGill University, Montreal
Dr. Brett J. Baker is a microbial ecologist and Associate Professor in the department of Integrative Biology at the University of Texas at Austin, affiliated with the Marine Science Institute.
Talk Description: The events that led to the origin of complex cellular life, eukaryotes, is a biological mystery. Asgard archaea were pivotal in the origin of complex cellular life. Hodarchaeales (Asgardarchaeota class Heimdallarchaeia) were recently shown to be the closest relatives of eukaryotes. A massive DNA sequencing of coastal and deep-sea sediments has doubled the number of Asgardarchaeota genomes. Global distribution analysis reveals that Heimdallarchaeia clades are present in a variety of marine environments and suggest niche partitioning, with Hodarchaeales primarily found in coastal marine sediments. Metabolic reconstructions suggest Heimdallarchaeia form distinct metabolic guilds from other Asgardarchaeota. These archaea encode hallmark proteins of aerobic lifestyle eukaryotes, suggesting the last common archaeal-eukaryotic ancestor was capable of oxygen utilization. Based on these findings, we have updated Heimdallarchaeiiea-centric model of the origin of eukaryotes in which key hallmarks for aerobic respiration may have been present in the Asgard-eukaryotic ancestor. We have also recently started to characterize the lipid composition of Hodarchaeales and have shown they contain pathways for dipternoids, that have been shown to mediate symbiotic interactions in bacteria. This expanded catalog of Asgard genomic diversity reveals that these Archaea likely conferred energetic advantages during the early stages of eukaryogenesis and constitutes a valuable resource for investigations into the origins and evolution of cellular complexity.