Conservation and Variability in Mitochondrial Genomes of Perlodidae: Insights from Comparative Mitogenomics

The mitochondrial genomes of three stoneflies, e.g., <i>Tibetisoperla wangluyui</i> Huo and Du, 2021, <i>Perlodinella kozlovi</i> Klapálek, 1912 and <i>Perlodinella epiproctalis</i> (Zwick, 1997), were sequenced in this study, with lengths 16,043 bp, 16,024 bp, and 16,071 bp, respectively. Each mitogenome contained 37 genes including 22 tRNAs, two ribosomal RNAs, 13 protein-coding genes (PCGs), and a noncoding control region (CR). In general, standard ATN start and TAN termination codons were evident in the PCGs. Meanwhile, in this paper, three newly published mitochondrial genomes and 11 existing mitochondrial genomes of the Perlodidae from NCBI were analyzed. Among the 13 PCGs in the mitochondrial genome of Perlodidae, the lengths of atp6, atp8, cox2, cox3, cytb, nad1, nad2, nad3, and nad4 are exactly the same, and the length of cox1 is 1536-1569 bp. The length of nad4L is 297, but the length of <i>Arcynopteryx dichroa</i> is 300. The length of nad5 ranges from 1732 bp to 1752 bp, while that of nad6 ranges from 525 bp to 534 bp. The length of rrnL is between 1292 and 391 bp, and the length of rrnS is between 793 and 869 bp. In addition, we found that atp8 in Isoperlinae started with GTG as a start codon but in Perlodinae, it started with ATG. Despite these advances, mitochondrial genome data from the Perlodidae are still needed.