Mitochondrial Genome Evolution in Arthropod Lineages

Mitochondrial genomes of arthropods are typically compact circular molecules encoding 13 protein-coding genes, two ribosomal RNAs and 22 transfer RNAs. Across lineages such as mites, ticks, spiders and crustaceans, mitochondrial gene order exhibits remarkable plasticity through transpositions, inversions and tandem duplications followed by random loss. Concurrently, many arthropod groups display extensive truncation of tRNA genes, frequently lacking one or both secondary arms yet retaining functionality through RNA editing or co-evolved protein factors. Comparative studies reveal that patterns of gene arrangement and nucleotide composition serve as powerful phylogenetic markers, resolving deep splits and clarifying relationships obscured by morphological convergence. Moreover, adaptive modifications in mitochondrial-encoded respiratory subunits reflect selective pressures associated with habitat transitions, from intertidal inundation to parasitic lifestyles, highlighting the central role of mitochondrial genome evolution in ecological diversification and species delimitation.

Research from Nature Portfolio

Analyses of oribatid mite mitogenomes demonstrate that sarcoptiform mites exhibit the least rearranged gene order relative to a basal arthropod pattern, while retaining a high number of complete cloverleaf-like tRNA structures—challenging the assumption that extreme tRNA reduction is universal in this group. In giant tarantulas, sequencing of complete mitogenomes uncovered multiple tRNA transpositions and a tandem duplication–random loss event, leading to unique synapomorphic gene boundaries. Comparative phylogenetic reconstructions combining gene order and sequence data yielded topologies concordant with morphological and multi-gene studies, and identified conserved control region motifs. These findings underscore how mitochondrial gene architecture both records evolutionary history and contributes to robust phylogenetic inference within Chelicerata.

Mitochondrial Genome Evolution in Arthropod Lineages publication trend

The graph below shows the total number of articles in mitochondrial genome evolution in arthropod lineages across all publications each year (not limited to Nature Index journals).

Technical terms

Mitochondrial genome: Circular DNA molecule within mitochondria encoding essential genes for oxidative phosphorylation and organelle biogenesis.

Gene rearrangement: Alteration of gene order or orientation through mechanisms such as inversions, transpositions or tandem duplication–random loss.

tRNA truncation: Reduction in transfer RNA length, often involving loss of D-arm or T-arm, requiring alternative secondary structures or editing for functionality.

Control region: Non-coding segment of mitochondrial DNA rich in adenine and thymine that regulates replication and transcription initiation.

Positive selection: Evolutionary process by which advantageous genetic variants rise in frequency, detectable through elevated ratios of nonsynonymous to synonymous substitutions.

References

1. Arm-less mitochondrial tRNAs conserved for over 30 millions of years in spiders. BMC Genomics (2019).
2. The Complete Mitochondrial Genome of endemic giant tarantula, Lyrognathus crotalus (Araneae: Theraphosidae) and comparative analysis. Scientific Reports (2020).
3. The mitochondrial genome of the oribatid mite Paraleius leontonychus: new insights into tRNA evolution and phylogenetic relationships in acariform mites. Scientific Reports (2018).
4. The complete mitochondrial genome of the intertidal spider (Desis jiaxiangi) provides novel insights into the adaptive evolution of the mitogenome and the evolution of spiders. BMC Ecology and Evolution (2021).