Recent advances in understanding mitochondrial genome diversity.
Level 5 - mechanism / opinion, no new human data
Narrative review of evolutionary genomics (graded Level 5 by design analogy)
PubMed 32399193 · doi:10.12688/f1000research.21490.1
What was done
This paper is a narrative review synthesizing recent high-throughput sequencing findings on the structural, functional, and evolutionary diversity of eukaryotic mitochondrial genomes (mitogenomes).
What was found
Mitogenome structure and size vary substantially across eukaryotic lineages. Animals maintain relatively compact genomes ranging from 11 to 50 kb with conserved gene content in bilaterians. Plant mitogenomes are significantly larger and more variable, ranging from 66 kb to 11.3 Mb, characterized by large intergenic repeats prone to recombination. Fungal mitogenomes occupy an intermediate size range of 12 to 236 kb. Across multicellular and unicellular eukaryotes, variations exist in conformation (circular vs. linear, single vs. multipartite), presence of self-splicing introns, gene order, genetic code usage, and transfer RNA editing, with some anaerobic unicellular lineages experiencing severe reduction or complete loss of the mitogenome.
Why it matters
Understanding the broad structural variability of mitochondrial genomes clarifies eukaryotic evolutionary trajectories and highlights the lineage-specific mechanisms governing organellar genome evolution.
Limits
The abstract describes a broad narrative synthesis rather than a systematic review or meta-analysis. It does not provide quantitative effect estimates, formal search parameters, or study selection criteria.
Cited by
- supports Cellular mitochondria originated as bacterial endosymbionts that integrated into eukaryotic cells and retain their own genome.