Complete mitochondrial genome sequence of the tiny dragonfly, Nannophya pygmaea (Odonata: Libellulidae)

Structures and genetic information of control region in mitogenomes of Odonata

Mitogenome data of Odonata is accumulating and widely used in phylogenetic analysis. However, noncoding regions, especially control region, were usually omitted from the phylogenetic reconstruction. In an effort to uncover the phylogenetic insights offered by the control region, we have amassed 65 Odonata mitogenomes and conducted an examination of their control regions. Our analysis discovered that species belonging to Anisoptera and Anisozygoptera exhibited a stem-loop structure, which was formed by a conserved polyC-polyG stretch located near the rrns gene (encoding 12S rRNA). Conversely, the polyC-polyG region was not a conserved fragment in Zygoptera. The length and number of repetitions within the control region were identified as the primary determinants of its overall length. Further, sibling species within Odonata, particularly those in the genus Euphaea, displayed similar patterns of repetition in their control region. Collectively, our research delineates the structural variations within the control region of Odonata and suggests the potential utility of this region in elucidating phylogenetic relationships among closely related species.

The complete mitochondrial genome of Chlorogomphus shanicus Wilson, 2002 (Anisoptera: Chlorogomphidae), an endemic species in South China

In this study, the complete mitochondrial genome of Chlorogomphus shanicus Wilson, 2002 was reported, and the maximum-likelihood (ML) phylogenetic tree was constructed using 13 protein-coding genes (PCGs). The total length of the mitogenome of C. shanicus was 15,497 bp. Twelve PCGs started with ATN codons, except cox1 began with TTG codon. Most transfer RNA genes (tRNAs) were predicted to fold in a typical cloverleaf structure, except the trnS1 (gct), which lacked a dihydrouridine arm that had been simplified to a loop. The phylogenetic tree showed that Anisoptera was split into two clades, and revealed that C. shanicus was closely related to Cordulegaster boltonii (Donovan, 1807) which is endemic to Europe.

Complete mitochondrial genome of Macromia manchurica Asahina, 1964 (Odonata: Macromiidae)

We describe the first time sequencing and assembly of the complete mitochondrial genome of Macromia manchurica Asahina, 1964 (Odonata; Macromiidae; Macromia). The mitochondrial genome of M. manchurica was found to be 15,560 bp. It contains thirteen protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and AT-rich region. The overall base composition of A. japonicus is A-38.6%, C-17.0%, G-12.5%, and T-31.9%. A phylogenetic analysis of 14 species within the order Odonata and order Ephemeroptera suggested that Macromia amphigena is most closely related to M. manchurica.

Complete mitochondrial genome of Asiagomphus coreanus (Odonata: Gomphidae), which is endemic to South Korea

Asiagomphus coreanus (Doi & Okumura, 1937) belongs to the family Gomphidae in the order Odonata, and has been listed as an endemic species in South Korea. Here, we assembled its complete mitochondrial genome (mitogenome) which is 15,649 base pairs (bp) in length. The A. coreanus mitogeneome consists of a typical set of genes [13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, and 22 transfer RNA (tRNA) genes] and one major non-coding A + T-rich region which is 846 bp long. The gene arrangement of the species was identical to that of commonly found in the majority of the insects. Phylogenetic analyses using the concatenated sequences of 13 PCGs and two rRNA genes of the representative odonate mitogenomes by Bayesian inference method revealed that A. coreanus belongs to the Gomphidae family with a strong nodal support (Bayesian posterior probabilities = 1). Unlike previous phylogenetic analyses (with regards to suborder relationships) the suborder Anisozygoptera—which was represented by a single species, Epiophlebia superstes—was placed as the sister to Zygoptera.

Characterization and phylogenetic analysis of the complete mitochondrial genome of Neurothemis fulvia (Odonata: Anisoptera: Libellulidae)

Neurothemis fulvia is a dragonfly of wet forests and usually perches on fallen logs and shrubs. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of N. fulvia. This mitogenome was 15,459 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and 2 ribosomal RNA unit genes (rRNAs). The nucleotide composition of the mitogenome was biased toward A and T, with 70.5% of A + T content (A 38.8%, T 31.7%, C 16.6%, and G 12.9%). Gene order was conserved and identical to most other previously sequenced Libellulidae dragonflies. Most PCGs of N. fulvia have the conventional start codons ATN (six ATG, three ATT, and two ATC), with the exception of cox1 and nad1 (TTG). Except for four PCGs (cox1, cox2, cox3, and nad5) end with the incomplete stop codon T––, all other PCGs terminated with the stop codon TAA or TAG. Phylogenetic analysis showed that N. fulvia got together with Tramea virginia with high support value. Libellulidae had a close relationship with Corduliidae, the relationships ((Hydrobasileus + Brachythemis) + (Orthetrum + (Acisoma + (Neurothemis + Tramea)))) were supported in Libellulidae.

Complete mitochondrial genome sequence of Bekko Tombo Libellula angelina Selys, 1883 (Odonata: Libellulidae)

The dragonfly Libellula angelina Selys, 1883 (Odonata: Libellulidae) has been listed as a critically endangered species by the International Union for Conservation of Nature (IUCN) and is also an endangered insect in South Korea. We sequenced the whole genome (15,233 bp) of L. angelina species, which included a set of typical genes and one major non-coding AT-rich region with an arrangement identical to that observed in most insect genomes. The A + T-rich region harbored one identical repeat composed of 65 bp and two tRNA-like structures (trnF and trnK-like sequences) with proper anticodon and clover-leaf structures. Phylogenetic reconstruction using the concatenated sequences of 13 protein-coding genes (PCGs) and two rRNAs of the representative odonate mitogenomes utilizing both Bayesian inference and maximum-likelihood methods revealed a strong support for the monophyletic Zygoptera and a moderate to high support for the monophyletic Anisoptera suborders. Unlike that in conventional phylogenetic analysis, a relatively strong sister relationship was revealed between the suborders of Anisozygoptera and Zygoptera.

Complete mitochondrial genome sequence of Macromia daimoji Okumura, 1949 (Odonata: Macromiidae)

The dragonfly Macromia daimoji Okumura, 1949 (Odonata: Macromiidae) has been listed as an Endangered insect in South Korea. We sequenced the complete 15,198 bp mitochondrial genome (mitogenome) of this organism, which is the first mitogenome sequence reported from the family Macromiidae. The genome includes a typical set of genes [13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes) and one non-coding region with an arrangement identical to that observed in most insect genomes. Phylogenetic analyses using concatenated sequences of the 13 PCGs and 2 rRNA genes using the Bayesian inference (BI) method placed Macromiidae, represented by M. daimoji, as a sister group to Libellulidae with the highest nodal support [Bayesian posterior probabilities (BPP) = 1]. Unlike conventional phylogenetic analysis, the suborders Anisozygoptera and Zygoptera formed a strong sister group (BPP =1), justifying the use of different molecular markers for phylogenetic analysis.