Complete Mitochondrial Genome of Suwallia teleckojensis (Plecoptera: Chloroperlidae) and Implications for the Higher Phylogeny of Stoneflies

Abstract

Stoneflies comprise an ancient group of insects, but the phylogenetic position of Plecoptera and phylogenetic relations within Plecoptera have long been controversial, and more molecular data is required to reconstruct precise phylogeny. Herein, we present the complete mitogenome of a stonefly, Suwallia teleckojensis, which is 16146 bp in length and consists of 13 protein-coding genes (PCGs), 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and a control region (CR). Most PCGs initiate with the standard start codon ATN. However, ND5 and ND1 started with GTG and TTG. Typical termination codons TAA and TAG were found in eleven PCGs, and the remaining two PCGs (COII and ND5) have incomplete termination codons. All transfer RNA genes (tRNAs) have the classic cloverleaf secondary structures, with the exception of tRNA^Ser(AGN), which lacks the dihydrouridine (DHU) arm. Secondary structures of the two ribosomal RNAs were shown referring to previous models. A large tandem repeat region, two potential stem-loop (SL) structures, Poly N structure (2 poly-A, 1 poly-T and 1 poly-C), and four conserved sequence blocks (CSBs) were detected in the control region. Finally, both maximum likelihood (ML) and Bayesian inference (BI) analyses suggested that the Capniidae was monophyletic, and the other five stonefly families form a monophyletic group. In this study, S. teleckojensis was closely related to Sweltsa longistyla, and Chloroperlidae and Perlidae were herein supported to be a sister group.

Keywords: Chloroperlidae; Plecoptera; Suwallia teleckojensis; mitochondrial genome; phylogenetics.

Figure A1

Phylogenetic trees generated from different datasets and methods. (A) The tree was obtained by BI analysis of the PCG13 dataset. (B) The tree was obtained by ML analysis of the PCG13 dataset. (C) The tree was obtained by BI analysis of the PCGR dataset. (D) The tree was obtained by ML analysis of the PCGR dataset.

Figure 1

Map of the mitochondrial genome of S. teleckojensis. Direction of gene transcription is indicated by the arrows. Protein-coding genes (PCGs) are shown as blue arrows, rRNA genes as purple arrows, tRNA genes as red arrows, and control region (CR) as gray arrows. tRNA genes are labeled according to single-letter IUPAC-IUB abbreviations (L1: UUR, L2: CUN, S1: AGN, S2: UCN). The GC content is plotted using a black sliding window, as the deviation from the average GC content of the entire sequence. GC skew is plotted as the deviation from the average GC skew of the entire sequence.

Figure 2

Secondary structures of 22 tRNAs of S. teleckojensis. All tRNAs are labeled with the abbreviations of their corresponding amino acids. Dashes (–) indicate Watson−Crick base pairing and dots (•) indicate G−U base pairing.

Figure 3

Predicted secondary structure of the lrRNA gene in S. teleckojensis. Roman numerals represent the conserved domain structures. Dashes (–) indicate Watson–Crick base pairings and dots (•) indicates G–U base pairing. I–VI indicate six domains in the secondary structure of lrRNA.

Figure 4

Predicted secondary structure of the srRNA gene in S. teleckojensis. Roman numerals denote the conserved domain structure. Dashes (−) indicate Watson-Crick base pairing and dots (•) indicate G–U base pairing. I–III indicate three domains in the secondary structure of srRNA.

Figure 5

Control region of the S. teleckojensis mitogenome. (A) Structure elements found in the control region of S. teleckojensis. (B) Putative stem-loop structures found in the control region of S. teleckojensis.

Figure 6

The alignment of conserved structural elements of CRs among stoneflies. Sequence identity among species was indicated by colored boxes. CSB1–4 indicates four conserved sequence blocks in the CRs. Blue color means 100% sequnce identity. Pink color means 75% sequnce identity. Green color means 50% sequnce identity.

Figure 7

Phylogenetic tree of the 16 sequenced stoneflies. Bayesian inference and Maximum Likelihood Analysis inferred from PCGs and PCGR supported the same topological structure. Values at nodes are ML bootstrap values and Bayesian posterior probabilities using the PCG13 (up) and PCGR (down) datasets. The tree was rooted with two outgroups (P. youi and I. ignota).