Obligate endosymbiosis enables genome expansion during eukaryogenesis

Journal article

The endosymbiosis of an alpha-proteobacterium that gave rise to mitochondria was one of the key events in eukaryogenesis. One striking outcome of eukaryogenesis was a much more complex cell with a large genome. Despite the existence of many alternative hypotheses for this and other patterns potentially related to endosymbiosis, a constructive evolutionary model in which these hypotheses can be studied is still lacking. Here, we present a theoretical approach in which we focus on the consequences rather than the causes of mitochondrial endosymbiosis. Using a constructive evolutionary model of cell-cycle regulation, we find that genome expansion and genome size asymmetry arise from emergent host–symbiont cell-cycle coordination. We also find that holobionts with large host and small symbiont genomes perform best on long timescales and mimic the outcome of eukaryogenesis. By designing and studying a constructive evolutionary model of obligate endosymbiosis, we uncovered some of the forces that may drive the patterns observed in nature. Our results provide a theoretical foundation for patterns related to mitochondrial endosymbiosis, such as genome size asymmetry, and reveal evolutionary outcomes that have not been considered so far, such as cell-cycle coordination without direct communication

Authors: von der Dunk, SHA; Hogeweg, P; Snel, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Communications Biology
• Volume: 6
• Issue: 1
• Pages: 777-777
• Article number: 777
• Publication date: 2023-07-25
• DOI: 10.1038/s42003-023-05153-x
• EISSN: 2399-3642
• ISSN: 2399-3642
• Language: English
• Keywords: Genome; Endosymbiosis; Ecology; Gene; Obligate; Genetics; Biology; Evolutionary biology; Plastid