Abstract
Mitochondrial genome evolution is shaped by organismal energy demands, with high-performance lineages typically showing stronger purifying selection on oxidative phosphorylation (OXPHOS) genes. We tested this relationship in Elateriformia beetles by analyzing 132 mitochondrial genomes from 15 families, categorizing species as heavily sclerotized active flyers (HARD), weakly sclerotized with reduced flight (WEAK), or sedentary larviform neotenic forms (NEOTENIC). PAML branch models revealed that dN/dS ratios varied systematically across all 13 protein-coding genes, with HARD lineages showing the strongest purifying selection, WEAK intermediate, and NEOTENIC the weakest, a pattern most pronounced in ATP8, which showed > 22-fold variation between categories. RELAX analyses confirmed that elevated dN/dS in neotenic lineages reflects weakened purifying selection rather than positive selection. Neotenic lineages also showed reduced GC content consistent with relaxed constraints. These patterns were consistent across multiple independent neotenic origins separated by > 200 million years, demonstrating that developmental shifts reallocating energy from locomotion to reproduction predictably relax mitochondrial OXPHOS constraints. Our findings extend metabolic rate principles established in vertebrates to hyper-diverse terrestrial arthropods.
Similar content being viewed by others
Shared regulatory networks link vein positioning and eyespot ring formation in butterflies
Massively parallel reporter perturbation assays uncover temporal regulatory architecture during neural differentiation
Precise modelling of mitochondrial diseases using optimized mitoBEs
Acknowledgements
The author(s) would like to thank the following individuals for providing the photographs used in Figure 1: Julien Touroult (B), Ben Keen (C), Zac Holt (D), Samuel Lee (F), and Chrissy McClarren & Andy Reago (G).
Funding
This research was funded by the Czech Science Foundation, grant number 22–35327 S (L.B., M.M., R.K., and D.K.).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Below is the link to the electronic supplementary material.
Supplementary Material 1 (download DOCX )
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Reprints and permissions
About this article
Cite this article
Motyka, M., Kusy, D., Bilkova, R. et al. Multiple independent origins of neoteny reveal convergent relaxation of mitochondrial selection in beetles.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-59230-2
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-59230-2
Source: Ecology - nature.com
