Mitonuclear Discordance of Beetles Shaped by Incomplete Lineage Sorting and Introgression Under Loose Interaction...

Area of Science:

• Evolutionary Biology
• Genomics
• Molecular Biology

Background:

• Metazoan oxidative phosphorylation (OXPHOS) complexes require coevolution of mitochondrial and nuclear genes.
• Mitochondrial and nuclear genomes have distinct inheritance patterns, potentially leading to evolutionary conflicts.

Purpose of the Study:

• To analyze phylogenetic signals of mitochondrial, nuclear-encoded OXPHOS, and general nuclear genes in 53 beetle species.
• To investigate instances and mechanisms of mitonuclear discordance in beetles.

Main Methods:

• Phylogenetic reconstructions using mitochondrial and nuclear genes.
• Reticulate evolutionary network analyses.
• Comparative analysis of gene evolutionary histories.

Main Results:

• Two cases of mitonuclear discordance were identified: noterids (OXPHOS divergence) and rhysodines (mitochondrial introgression).
• Mitonuclear discordance in noterids attributed to incomplete lineage sorting; rhysodines showed introgressive hybridization.
• Limited efficacy of nuclear compensation at the gene level, with weak correlations between nuclear-encoded OXPHOS and mitochondrial genes.

Conclusions:

• Beetles exhibit loose mitonuclear interactions, with decoupled evolutionary trajectories.
• This decoupling may act as an evolutionary buffer for genomic conflicts.
• Essential OXPHOS systems are maintained despite independent evolutionary paths of genomes.