Comparative Analysis of the Mitochondrial Genomes of Five Species of Anabropsis (Orthoptera: Anostostomatidae) and the Phylogenetic Implications of Anostostomatidae

TL;DR

This study analyzes mitochondrial genomes of five Anabropsis species to clarify their evolutionary relationships and challenges previous classifications.

Contribution

The study provides new mitochondrial genome data for Anabropsis species and reveals their phylogenetic relationships using Bayesian and maximum likelihood methods.

Findings

Anabropsini is not monophyletic, suggesting the need for taxonomic revision.

Anabropsis is monophyletic with a stable subgeneric topology.

Ka/Ks values suggest wing length alone is unreliable for subgeneric classification.

Abstract

In China, the Anostostomatidae family is represented by a single tribe, Anabropsini, and two genera (Anabropsis and Melanabropsis). However, molecular data for Anabropsini remain limited, and its monophyly remains unverified. The phylogenetic relationships among the Anabropsis subgenera are also debated. To address these gaps, we sequenced and analyzed the mitochondrial genomes of five Anabropsis species. Additionally, we reconstructed the phylogeny of Anostostomatidae using maximum likelihood and Bayesian inference methods. The results indicated that Anabropsini is not monophyletic, and the topological structure between subgenera within the Anabropsis genus is stable.

In China, Anostostomatidae is represented by a single tribe, Anabropsini; two genera; and 33 species. Although extensive research has been conducted on Anabropsini, the monophyly of this tribe within Anostostomatidae remains unverified. Furthermore, the phylogenetic relationships within Anabropsis remain under debate. To address these gaps, we sequenced and annotated the mitochondrial genomes of five Anabropsini species to investigate their mitochondrial characteristics and phylogenetic positions and clarify the relationships among Anabropsis subgenera. The total mitochondrial length of the five species ranged from 15,985 bp to 16,423 bp and contained 13 protein-coding genes, 22 tRNAs, 2 rRNAs, and 1 control region. A grouped analysis of selection pressure on Anabropsis revealed that the Ka/Ks values for alate and apterous forms are not significantly different, suggesting that using wing length alone as the basis for dividing subgenera within Anabropsis may be unreliable. Tertiary structure modeling of proteins showed that the variable sites were concentrated in α-helix regions. Phylogenetic trees were reconstructed using the Bayesian inference and maximum likelihood methods and were based on two better datasets, namely, PCG123 (all codon positions of the PCGs) and PCG123 + 2R (all codon positions of PCGs, 12SrRNA, and 16SrRNA). The results indicate that the Chinese Anabropsini is paraphyletic, whereas Anabropsis is monophyletic, with a stable subgeneric topology.

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