Exploring the Mitogenomes of Acroneuriinae: The First Report of Gene Rearrangements in Plecoptera Species and Phylogenetic Analyses of Perlidae.

Perlidae represents one of the most diverse and ecologically important groups within the order Plecoptera. However, the phylogenetic relationships within Perlidae remain unresolved due to morphological plasticity and the limited availability of molecular data. Here we sequenced and assembled the mitogenome of Hemacroneuria ovalis and Hesperoperla pacifica. By comparing with other published Acroneuriinae mitogenomes, we found that minimal length variation in protein-coding genes (PCGs), transfer RNA genes (tRNAs), and ribosomal RNA genes (rRNAs), whereas the control region (CR) exhibits considerable length divergence. Meanwhile, the mitogenome of Acroneuriinae species is relatively conserved in nucleotide composition and codon usage. The nucleotide diversity (Pi) and Ka/Ks values indicated that the ND6 gene evolves at a faster rate than the COI gene, and all 13 PCGs are under purifying selection. We also identified gene rearrangement in these two mitogenomes, representing the first report of such events in the order Plecoptera. Phylogenetic results support the monophyly of the tribes Claasseniini, Neoperlini, and Kiotinini, as well as the subfamily Perlinae. Trees from the PCG and PCG12 datasets exhibited more congruent and well accepted topologies. Although both Acroneuriini and Perlini failed to demonstrate monophyly, the phylogenetic relationships among the five families of Perlidae were still reconstructed as (((Perlini + Neoperlini) + Claasseniini) + Kiotinini) + Acroneuriini.