Rethinking eukaryogenesis: genomic signatures suggest an aerobic host.

Abstract

The long-standing paradigm of a strictly 'anaerobic host' for eukaryogenesis is fundamentally challenged by an expanded genomic catalog of Asgard archaea. Recent genomic predictions by Appler et al. reveal that Heimdallarchaeia, the closest archaeal relatives to eukaryotes, encode hallmark proteins of an aerobic lifestyle, suggesting they may have harbored the potential for aerobic respiration prior to mitochondrial endosymbiosis.