Cytonuclear discordance explained

Cytonuclear discordance describes the discrepancy in phylogenetic relationships using mitochondrial DNA (mtDNA) versus nuclear genes (or nuclear DNA, nDNA). In other words, mitochondrial and nuclear gene sequences may lead to different, if not contradictory, phylogenetic trees that show the relationships among species. In theory, nuclear DNA and mtDNA sequences should lead to similar phylogenetic tree topologies among species but this is often not the case.

Other terms for the concept are Nuclear-mitochondrial discordance or mito-nuclear discordance.

Examples

An example are Australian rock-wallabies (Petrogale) in which several species form a monophyletic group with nDNA genes, but not with mtDNA. This cytonuclear discordance involves at least four operational taxonomic units (OTUs) across four species.^[1]

Another example is the relationship among grasshoppers (Orthoptera). Phylogenies based on complete mitogenomes recovered some species as para- or polyphyletic. By contrast, a phylogeny based on nuclear genes derived from transcriptomic data retrieved all species as monophyletic clusters.^[2]

Many other taxonomic groups display cytonuclear discordance, e.g. Burmese pythons^[3] or vipers of the genus Cerastes.

Notes and References

Potter . Sally . Moritz . Craig . Piggott . Maxine P . Bragg . Jason G . Afonso Silva . Ana C . Bi . Ke . McDonald-Spicer . Christiana . Turakulov . Rustamzhon . Eldridge . Mark D B . 2024-04-05 . Museum skins enable identification of introgression associated with cytonuclear discordance . Systematic Biology . 73 . 3 . 579–593 . en . 10.1093/sysbio/syae016 . 1063-5157. free . 11377193 .
Hawlitschek . Oliver . Ortiz . Edgardo M. . Noori . Sajad . Webster . Kathleen C. . Husemann . Martin . Pereira . Ricardo J. . May 2022 . Transcriptomic data reveals nuclear-mitochondrial discordance in Gomphocerinae grasshoppers (Insecta: Orthoptera: Acrididae) . Molecular Phylogenetics and Evolution . en . 170 . 107439 . 10.1016/j.ympev.2022.107439.
Hunter . Margaret E. . Johnson . Nathan A. . Smith . Brian J. . Davis . Michelle C. . Butterfield . John S. S. . Snow . Ray W. . Hart . Kristen M. . September 2018 . Cytonuclear discordance in the Florida Everglades invasive Burmese python (Python bivittatu s) population reveals possible hybridization with the Indian python (P. molurus) . Ecology and Evolution . en . 8 . 17 . 9034–9047 . 10.1002/ece3.4423 . 2045-7758 . 6157680 . 30271564. 2018EcoEv...8.9034H .