Evolutionary codependency: insights into the mitonuclear interaction landscape from experimental and wild Caenorhabditis nematodes

Aided by new technologies, the upsurgence of research into mitochondrial genome biology during the past 15 years suggests that we have misunderstood, and perhaps dramatically underestimated, the ongoing biological and evolutionary significance of our long-time symbiotic partner. While we have begun to scratch the surface of several topics, many questions regarding the nature of mutation and selection in the mitochondrial genome, and the nature of its relationship to the nuclear genome, remain unanswered. Although best known for their contributions to studies of developmental and aging biology, Caenorhabditis nematodes are increasingly recognized as excellent model systems to advance understanding in these areas. We review recent discoveries with relevance to mitonuclear coevolution and conflict and offer several fertile areas for future work. •Caenorhabditis are versatile models for mitonuclear coevolution research.•C. elegans mitochondrial DNA mutation spectra may reflect oxidative DNA damage.•Mitochondrial DNA deletions segregate in wild isolates and readily occur in the lab.•Nuclear-encoded mechanisms promote expansion of mitochondrial DNA deletions.•Mitochondrial genomes may be an underappreciated source of rapid adaptation.