Jul 2026· Journal of the Entomological Research Society· 0 citations· 60 references
TL;DR
The first complete mitogenome of Eurostus validus is reported and indicates that both mutation pressure and natural selection shape codon usage bias, with natural selection playing a dominant role.
Abstract
The genus Eurostus is distributed across East and Southeast Asia, inhabiting forest and agricultural ecosystems and participating in plant-insect interactions. However, the absence of a complete mitochondrial genome has limited understanding of its evolution and phylogeny. Here, we report the first complete mitogenome of Eurostus validus. The circular genome is 15,948 bp and contains the typical 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs, two ribosomal RNAs, and a control region. Comparative analyses with other tessaratomid mitogenomes revealed strong AT bias, consistent strand asymmetry, and conserved patterns of amino acid and codon usage. Among Pentatomoidea, atp8 showed the highest nucleotide diversity, whereas cox1 was the most conserved. ENC-plot and neutrality analyses indicated that both mutation pressure and natural selection shape codon usage bias, with natural selection playing a dominant role. Phylogenetic analyses based on the PCG12RNA dataset using Bayesian inference and maximum likelihood strongly supported family monophyly. The topology recovered Dinidoridae and Tessaratomidae as sister groups, with well-resolved relationships within Tessaratomidae. These results provide a valuable genomic resource and improve understanding of Pentatomoidea evolution.
The infraorder Spiruromorpha comprises diverse parasitic nematodes of veterinary and medical importance, many of which utilize arthropods as intermediate hosts/vectors. However, phylogenetic relationships and evolutionary history within this group remain poorly resolved due to limitations of single-gene markers and the scarcity of fossil records. Complete mitochondrial genomes offer robust alternatives for resolving deep evolutionary radiations and understanding adaptive processes relevant to parasite–vector–host interactions.
We assembled and characterized the first complete mitochondrial genome of
Cyrnea seurati
(Habronematoidea) from a Eurasian hobby (
Falco subbuteo
) in China. The 13,761 bp circular genome contains 12 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs, with gene arrangement conserved within Habronematoidea but featuring unique initiation codons (GTT for
nad4
and TTT for
cytb
). Comparative analysis revealed high genetic divergence from other Habronematoidea species (20.5–37.4% in nucleotide sequences), confirming its distinct generic status. Phylogenomic analyses of 54 Spiruromorpha mitogenomes resolved two major clades and widespread paraphyly among superfamilies, with mitochondrial data providing greater resolution than 18S rRNA. Divergence time estimation, calibrated using published fossil records, traced the most recent common ancestor of Spiruromorpha to the Devonian (~ 366.77 Mya), with major radiations coinciding with the Jurassic–Cretaceous transition—a period marked by diversification of insect vectors and vertebrate hosts. Positive selection was detected in nine PCGs, notably in OXPHOS genes (
cox2
,
cytb
,
nad1
,
nad6
), suggesting adaptive evolution to diverse host environments and metabolic demands. Codon usage analysis revealed strong AT-biased preferences and species-specific adaptive patterns linked to host origins.
This study provides the first mitogenomic resource for the genus
Cyrnea
, significantly advancing the molecular dataset for Spiruromorpha. Our phylogenomic framework resolves long-standing uncertainties in spiruromorph relationships and highlights the potential of mitochondrial markers for tracing parasite–vector coevolutionary dynamics. The detected positive selection signals implicate mitochondrial adaptation in the ecological diversification of these parasites, with implications for understanding nematode parasitism, pathogen control, and the evolutionary interplay between parasites, vectors, and hosts.
Yuan-Ping Deng, Aiyun Zhao, Yi-Liu Liu et al.· Parasites & Vectors· 0 citations
Combined mitogenomic and multi-locus phylogenomics clarified the phylogenetic placement of these taxa and provided timescale estimates for their divergence and enriches the mitogenomic resources of Phytophthora from pristine natural ecosystems.
Yi-Jia Sun, Xiao-Wei Chen, Wenxin Wang et al.· IMA Fungus· 0 citations
We employed second-generation sequencing technology to determine the complete mitochondrial genome of Mioscirtus w. wagneri (Eversmann, 1859), which is the first species reported in the genus Mioscirtus. The mitochondrial genome spans 15,632 base pairs and encodes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and an AT-rich control region (D-loop region). The nucleotide composition exhibits a strongly A+T bias (75.6%). Among the 13 PCGs, 27 codons exhibited higher usage frequencies, predominantly with A/U endings. All tRNA genes adopt the canonical cloverleaf secondary structure, except for tRNASer(AGN), which lacks the dihydrouridine (DHU) arm. Nucleotide diversity and evolutionary rate analyses across mitogenomes of Oedipodinae revealed pervasive purifying selection acting on all 13 PCGs (Ka/Ks < 1). Among these, ND2 exhibited the highest nucleotide diversity, whereas ND4L exhibited the lowest. Phylogenetic analyses were conducted based on the concatenated nucleotide sequences of all 13 PCGs, using both Maximum likelihood (ML) and Bayesian inference (BI) frameworks, which produced an identical topology strongly supported M. w. wagneri as a monophyletic lineage within the subfamily Oedipodinae. This lineage formed a sister group relationship with species of the genus Celes and shared a most recent common ancestor with species of the genus Oedipoda, together constituting the tribe Oedipodini. This phylogenetic relationship is consistent with traditional morphology-based classifications. These findings expand the currently sparse mitogenomic resource for the subfamily Oedipodinae and provide a robust genetic foundation for future studies on the population genetics and evolutionary history of M. w. wagneri.
The complete plastome of C. erectus is characterized, providing the first complete cp genome resource for C. erectus, and offering a foundation for further phylogenomic and conservation studies within Arecaceae.
Sheikh Sunzid, S. Ahmed, Nusrat Jahan et al.· Korean Journal of Plant Taxo...· 0 citations
