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Extreme weather poses huge challenges for animals that must adapt to wide variations in environmental temperature and, in many cases, it can lead to the local extirpation of populations or even the extinction of an entire species. Previous studies have found that one element of amphibian adaptation to environmental stress involves changes in mitochondrial gene expression at low temperatures. However, to date, comparative studies of gene expression in organisms living at extreme temperatures have focused mainly on nuclear genes. This study sequenced the complete mitochondrial genomes of five Asian hylid frog species: Dryophytes japonicus , D. immaculata , Hyla annectans , H. chinensis and H. zhaopingensis . It compared the phylogenetic relationships within the Hylidae family and explored the association between mitochondrial gene expression and evolutionary adaptations to cold stress. The present results showed that in D. immaculata , transcript levels of 12 out of 13 mitochondria genes were significantly reduced under cold exposure ( p < 0.05); hence, we put forward the conjecture that D . immaculata adapts by entering a hibernation state at low temperature. In H. annectans , the transcripts of 10 genes ( ND1 , ND2 , ND3 , ND4 , ND4L , ND5 , ND6 , COX1 , COX2 and ATP8 ) were significantly reduced in response to cold exposure, and five mitochondrial genes in H. chinensis ( ND1 , ND2 , ND3 , ND4L and ATP6 ) also showed significantly reduced expression and transcript levels under cold conditions. By contrast, transcript levels of ND2 and ATP6 in H . zhaopingensis were significantly increased at low temperatures, possibly related to the narrow distribution of this species primarily at low latitudes. Indeed, H. zhaopingensis has little ability to adapt to low temperature (4 °C), or maybe to enter into hibernation, and it shows metabolic disorder in the cold. The present study demonstrates that the regulatory trend of mitochondrial gene expression in amphibians is correlated with their ability to adapt to variable climates in extreme environments. These results can predict which species are more likely to undergo extirpation or extinction with climate change and, thereby, provide new ideas for the study of species extinction in highly variable winter climates.

Dryophytes versicolor is one of the most extreme freeze-tolerant frogs from eastern North America. In this study, the mitochondrial genome of D. versicolor was sequenced to analyze the phylogenetic relationships among Hylidae and investigate mitochondrial gene expression in response to freezing and anoxia. The total length of the D. versicolor mitogenome is the longest known to date among the available family members of Hylidae. Both maximum likelihood (ML) and Bayesian inference (BI) analyses strongly supported D. versicolor as a sister clade to (D. japonica + D. ussuriensis) + (D. suweonensis + D. immaculata (KP212702)), and indicated that Dryophytes is monophyletic. Using the mitochondrial genome, gene expression analysis was performed using RT-qPCR in skeletal muscle samples, and determined that relative levels of D. versicolor COX2 increased by 2.40 ± 0.23 fold in response to anoxia, but did not change with exposure to freezing. In addition, ND3 transcript levels decreased in response to anoxia but remained constant during freezing. By contrast, COX1 transcript levels decreased with exposure to freezing, but did not change under anoxic conditions. These results suggest that modulations of protein-coding mitochondrial genes of D. versicolor may play a role in the molecular response to freezing and anoxia tolerance., (Copyright © 2019. Published by Elsevier B.V.)

We acquired 21 complete mitogenomes and 6 nearly complete mitogenomes of mantises belonging to 8 families (Hymenopodidae, Iridopterygidae, Mantidae, Metallyticidae, Sibyllidae, Tarachodidae, Thespidae, Toxoderidae) using 14 pairs of mantid specific primer sets and found that 5 species of mantises have duplicate copies (2-4) of trnR: Ambivia undata, Creobroter jiangxiensis, Creobroter urbanus, Phyllothelys sp1. and Theopropus elegans while two novel gene arrangements CR-I-NCR-I-NCR-I-NCR-I-NCR-I-NCR*-Q-M and COII-K*-D*-K-D*-K-D*-K-D were found in Schizocephala bicornis and Stenotoxodera porioni, respectively. The multiple copies of trnR are caused by independent duplications. The gene arrangements in Stenotoxodera porioni with three identical copies of trnK can be explained as mid-way through the TDRL process while the form of gene arrangement in Schizocephala bicornis is unclear. In the phylogeny at the family level, the monophyly of Liturgusidae and Iridopterygidae was supported, whereas the monophyly of Hymenopodidae, Mantidae and Tarachodidae wasn't. The features of mantis mitochondrial genomes including high duplication rates of trnR, trnK and trnI indicate that Mantodea mitochondrial genomes maybe a useful model system for studying gene duplication. However, derived gene arrangements may not be appropriate for phylogenetic inference in Mantodea as they aren't synapomorphy and aren't shared by close relatives., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Complete mitochondrial (mt) genomes have been used extensively to test hypotheses about microevolution and to study population structure, phylogeography, and phylogenetic relationships of Anura at various taxonomic levels. Large-scale mt genomic reorganizations have been observed among many fork-tongued frogs (family Dicroglossidae). The relationships among Dicroglossidae and validation of the genus Feirana are still problematic. Hence, we sequenced the complete mt genomes of Nanorana taihangnica (=F. taihangnica) and N. yunnanensis as well as partial mt genomes of six Quasipaa species (dicroglossid taxa), two Odorrana and two Amolops species (Ranidae), and one Rhacophorus species (Rhacophoridae) in order to identify unknown mt gene rearrangements, to investigate the validity of the genus Feirana, and to test the phylogenetic relationship of Dicroglossidae., Results: In the mt genome of N. taihangnica two trnM genes, two trnP genes and two control regions were found. In addition, the trnA, trnN, trnC, and trnQ genes were translocated from their typical positions. In the mt genome of N. yunnanensis, three control regions were found and eight genes (ND6, trnP, trnQ, trnA, trnN, trnC, trnY and trnS genes) in the L-stand were translocated from their typical position and grouped together. We also found intraspecific rearrangement of the mitochondrial genomes in N. taihangnica and Quasipaa boulengeri. In phylogenetic trees, the genus Feirana nested deeply within the clade of genus Nanorana, indicating that the genus Feirana may be a synonym to Nanorana. Ranidae as a sister clade to Dicroglossidae and the clade of (Ranidae + Dicroglossidae) as a sister clade to (Mantellidae + Rhacophoridae) were well supported in BI analysis but low bootstrap in ML analysis., Conclusions: We found that the gene arrangements of N. taihangnica and N. yunnanensis differed from other published dicroglossid mt genomes. The gene arrangements in N. taihangnica and N. yunnanensis could be explained by the Tandem Duplication and Random Loss (TDRL) and the Dimer-Mitogenome and Non-Random Loss (DMNR) models, respectively. The invalidation of the genus Feirana is supported in this study.

The mt genome of Paa spinosa (Anura: Ranoidae) is a circular molecule of 18,012 bp in length, containing 38 genes (including an extra copy of tRNA-Met gene). This mt genome is characterized by three distinctive features: a cluster of rearranged tRNA genes (LTPF tRNA gene cluster), a tandem duplication of tRNA-Met gene (Met1 and Met2), and distinct repeat regions at both 5' and 3'-sides in the control region. Comparing the locations and the sequences of all tRNA-Met genes among Ranoidae, and constructing NJ tree of the nucleotide of those tRNA-Met genes, we suggested a tandem duplication of tRNA-Met gene can be regarded as a synapomorphy of Dicroglossinae. To further investigate the phylogenetic relationships of anurans, phylogenetic analyses (BI, ML and MP) based on the nucleotide dataset and the corresponding amino acid dataset of 11 protein-coding genes (except ND5 and ATP8) arrived at the similar topology.

Simple Summary: Lamiinae is the largest subfamily among the Cerambycidae (longhorn beetles), and its members are distributed worldwide. The monophyly of Lamiinae is generally recognized, but there are still diverse ideas as to whether the tribes belonging to Lamiinae are monophylic. Ambiguous classification boundaries and the existence of synonyms are major issues leading to controversies over Lamiinae classification. It is not enough to conduct research solely on the morphological characteristics and simple molecular loci of longhorn beetles. Mitochondrial genomes have proven to be reliable markers and can shed more light on phylogenetic relationships among Lamiinae. The present study resolved infra-subfamilial relationships among Lamiinae and provides more mitochondrial data for further phylogenetic research on longhorn beetles. Lamiinae is the largest subfamily of the Cerambycidae (longhorn beetles), with approximately 21,863 described species. Previous phylogenetic studies of Lamiinae showed that this subfamily was monophyletic, but the relationship between the tribes of Lamiinae is still controversial. Partial molecular data and species morphological characteristics are not sufficient to resolve species phylogenetic studies perfectly. At the same time, the full mitochondrial genome contains more comprehensive genetic data. Benefiting from the development of next-generation sequencing (NGS), mitochondrial genomes can be easily acquired and used as reliable molecular markers to investigate phylogenetic relationships within Cerambycidae. Using NGS technology, we obtained 11 mitochondrial genome sequences of Lamiinae species. Based on this newly generated mitochondrial genome dataset matrix, we reconstructed the phylogeny of Lamiinae. The Bayesian Inference and Maximum Likelihood analyses strongly support the monophyly of four tribes (Lamiini, Batocerini, Mesosini, and Saperdini), whereas the tribe Acanthocinini was identified as paraphyletic. Other mitochondrial structural features were also observed: the start codon in the nad1 gene of all 11 mitochondrial genomes is TTG; 17–22 bp intergenic spacers (IGS) with a 'TACTA' motif were found between trnS2 and nad1. Moreover, two long IGS were found in Mesosa myops and Batocera sp. Tandem repeats were found in the IGS of Batocera sp. [ABSTRACT FROM AUTHOR]

Simple Summary: The tropical and subtropical paddy frog, Fejervarya kawamurai (Anura: Dicroglossidae), is a common and widespread species in Asia. Amphibians can adapt to small changes in climate, but extreme temperature changes can lead to metabolic abnormalities affecting numerous cell functions. Damage or disruption of mitochondrial respiratory chain complexes can be lethal. The present study characterizes the mitochondrial genome of F. kawamurai to evaluate its evolutionary relationship within Dicroglossidae and to analyze the effects of extreme temperature change on mitochondrial gene expression of proteins involved in oxidative phosphorylation. Unusual climates can lead to extreme temperatures. Fejervarya kawamurai, one of the most prevalent anurans in the paddy fields of tropical and subtropical regions in Asia, is sensitive to climate change. The present study focuses primarily on a single question: how do the 13 mitochondrial protein-coding genes (PCGs) respond to extreme temperature change compared with 25 °C controls? Thirty-eight genes including an extra tRNA-Met gene were identified and sequenced from the mitochondrial genome of F. kawamurai. Evolutionary relationships were assessed within the Dicroglossidae and showed that Dicroglossinae is monophyletic and F. kawamurai is a sister group to the clade of (F. multistriata + F. limnocharis). Transcript levels of mitochondrial genes in liver were also evaluated to assess responses to 24 h exposure to low (2 °C and 4 °C) or high (40 °C) temperatures. Under 2 °C, seven genes showed significant changes in liver transcript levels, among which transcript levels of ATP8, ND1, ND2, ND3, ND4, and Cytb increased, respectively, and ND5 decreased. However, exposure to 4 °C for 24 h was very different in that the expressions of ten mitochondrial protein-coding genes, except ND1, ND3, and Cytb, were significantly downregulated. Among them, the transcript level of ND5 was most significantly downregulated, decreasing by 0.28-fold. Exposure to a hot environment at 40 °C for 24 h resulted in a marked difference in transcript responses with strong upregulation of eight genes, ranging from a 1.52-fold increase in ND4L to a 2.18-fold rise in Cytb transcript levels, although COI and ND5 were reduced to 0.56 and 0.67, respectively, compared with the controls. Overall, these results suggest that at 4 °C, F. kawamurai appears to have entered a hypometabolic state of hibernation, whereas its mitochondrial oxidative phosphorylation was affected at both 2 °C and 40 °C. The majority of mitochondrial PCGs exhibited substantial changes at all three temperatures, indicating that frogs such as F. kawamurai that inhabit tropical or subtropical regions are susceptible to ambient temperature changes and can quickly employ compensating adjustments to proteins involved in the mitochondrial electron transport chain. [ABSTRACT FROM AUTHOR]

Mantodea is a predatory insect group, its members occupying a diverse array of widely distributed habitats. Praying mantis species utilize hunting strategies including remarkable mimicry and unique camouflage for hiding from natural enemies while catching their prey. The emergence of a "cyclopean ear" in mantises is thought to be a morphological innovation of the group, and an "arms race" with echolocating bats is one of the hypotheses put forward to account for the emergence of the mantis ear from a coevolutionary perspective. However, this hypothesis has not been rigorously tested because of a lack of robust higher‐level phylogeny and a detailed chronogram of Mantodea. Previous phylogenetic studies found an incongruence between traditional classification and molecular phylogenetics due to the convergent evolution of various ecomorphic strategies of the lineage. Here, we performed a comprehensive phylogenetic analysis of Mantodea based on data from 61 mitogenomes. Our analyses showed that the monophyly of Acanthopidae, Haaniidae, Nanomantidae, Miomantidae and Mantidea was supported. The newly updated Gonypetidae were paraphyletic, whereas Eremiaphilidae, Deroplatyidae and Toxoderidae were polyphyletic. Our molecular dating analyses inferred that Spinomantodea originated at ca. 149 Ma (Late Jurassic), whereas the origin of hearing mantises (Cernomantodea) was inferred as Early Cretaceous (119 Ma, 95% CI: 110–129 Ma). The molecular dating results indicated that the hearing organ in mantises did not arise in response to bat predation. Our study provides a robust framework for further evolutionary comparative studies of mantises. [ABSTRACT FROM AUTHOR]

Simple Summary: Hylidae is a rich family of Anura that is widely distributed across the world. Previous studies have shown that the Hyla and Dryophytos genera in the Hylidae used to belong to the same genus. The Eurasian species (including Hyla sanchiangensis) originated in North America and spread through the Beringian Land Bridge to Asia during the last ice age. Adaptation to low temperatures may require more energy expenditure. Mitochondria are the center of energy metabolism and, through oxidative phosphorylation, provide most of the ATP energy for the physiological and biochemical activities of the body. The mitogenome was used to investigate whether Hyla and Dryophytos genera are subject to positive selection. In addition, as a unique species in China, the distinction between Hyla sanchiangensis (Anura: Hylidae) and two different sites was also compared and analyzed in this paper. Hyla sanchiangensis (Anura: Hylidae) is endemic to China and is distributed across Anhui, Zhejiang, Fujian, Guangdong, Guangxi, Hunan, and Guizhou provinces. The mitogenomes of H. sanchiangensis from two different sites (Jinxiu, Guangxi, and Wencheng, Zhejiang) were sequenced. Phylogenetic analyses were conducted, including 38 mitogenomes of Hylidae from the NCBI database, and assessed the phylogenetic relationship of H. sanchiangensis within the analyzed dataset. Two mitogenomes of H. sanchiangensis showed the typical mitochondrial gene arrangement with 13 protein-coding genes (PCGs), two ribosomal RNA genes (12S rRNA and 16S rRNA), 22 transfer RNA (tRNA) genes, and one non-coding control region (D-loop). The lengths of the 12S rRNA and 16S rRNA genes from both samples (Jinxiu and Wencheng) were 933 bp and 1604 bp, respectively. The genetic distance (p-distance transformed into percent) on the basis of the mitogenomes (excluding the control region) of the two samples was calculated as 4.4%. Hyla sanchiangensis showed a close phylogenetic relationship with the clade of (H. annectans + H. tsinlingensis), which was supported by ML and BI analyses. In the branch-site model, five positive selection sites were found in the clade of Hyla and Dryophytes: Cytb protein (at position 316), ND3 protein (at position 85), and ND5 protein (at position 400) have one site, respectively, and two sites in ND4 protein (at positions 47 and 200). Based on the results, we hypothesized that the positive selection of Hyla and Dryophytes was due to their experience of cold stress in historical events, but more evidence is needed to support this conclusion. [ABSTRACT FROM AUTHOR]

The complete mitochondrial (mt) genome of Leptomantella tonkinae (Hebard, 1920) was 15,527 bp in length and contained 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs, and one control region. The gene arrangement of mt genome of L. tonkinae was identical to the primitive mantis. The overall AT content of the mt genome was 74%. In ML and BI phylogenetic analyses, the monophyly of Leptomantellidae was robustly supported and the clade of Leptomantellidae is a sister clade to the group of (Gonypetidae+(Leptomantellidae+(Amorphoscelidae+Nanomantidae))). [ABSTRACT FROM AUTHOR]

The phylogenetic relationship of Ephemeridae (Insect: Ephemeroptera) remains hotly debated using mitochondrial (mt) genomes. All previously reported mt genomes of Ephemeridae belong to the genus Ephemera. This study provides the first complete mt genome sequence from the genus Hexagenia with an analysis of the mitogenome of Hexagenia rigida Mc Dunnough, 1924 (Ephemeroptera: Ephemeridae) and providing new information to discuss the phylogenetic relationships within Ephemeroptera. The complete mt genome of H. rigida was a circular molecule of 16,159 bp in length, containing 37 genes (2 rRNA genes, 13 protein-coding genes, 22 tRNA genes), which showed the typical mt gene arrangement of insects. The AT content of the whole genome was 70.0% and the length of the control region was 1091 bp. All protein-coding genes used ATN as the start codon, and most PCGs used TAA/TAG as the stop codons excluding COI, COII, ND5 and Cyt b that used T as the stop codon. BI and ML phylogenetic trees constructed from 27 species of 13 families showed that Ephemeridae is a sister clade to the clade Polymitarcyidae. [ABSTRACT FROM AUTHOR]

Rana johnsi (Smith 2009) firstly considered as the member of genus Pseudorana, has been moved into the genus Rana. In this study, we sequenced the complete mitochondrial (mt) genome of R. johnsi using the Sanger method. The circular mt genome was 17,873 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosome RNA genes, and one control region. The overall nucleotide composition in majority-strand was 28% A, 29% T, 29% C, and 14% G. We discussed the phylogenetic relationship of R. johnsi in genus Rana using ML and BI analyses based on 13 PCGs. Excluding the clade of subgenus Lithobates, Rana draytonii was the basal clade to all other Rana species, which included R. johnsi as the basal clade. The monophyly of genus Rana was supported, whereas Pseudorana was failed to support. [ABSTRACT FROM AUTHOR]

The Lonchodinae (Phasmatodea: Phasmatidae) is rich in insect species with more than 330 species of 40 genera. The phylogenetic relationships within Lonchodinae have been under debate. We successfully sequenced the complete mitogenome of Eurycantha calcarata Lucas, 1869 (Phasmatodea: Lonchodinae) with a length of 16,280 bp, which had the same genes and gene arrangements as those of various published papers on stick insects. The whole mitogenome and control region of E. calcarata had a high AT content of 78.2 and 85.9%, respectively. All PCGs used ATN as the start codon, and most PCGs used TAA/TAG as the stop codons excluding COX2 (T), COX3 (TA), and ND5 (TA). To discuss the phylogeny of Lonchodinae, we reconstructed the phylogenetic relationships of 27 species of Phasmatodea including E. calcarata and two species of Embioptera used as outgroups. In BI and ML trees, the monophyly of Lonchodinae and Necrosciinae was well supported, whereas the monophyly of Clitumninae was not recovered. These results indicated that Lonchodinae was a sister clade to Phylliinae and E. calcarata was a sister clade to Phraortes genus. [ABSTRACT FROM AUTHOR]

Zoodes fulguratus is a common species of Cerambycidae, reported from Vietnam, Nepal, Laos, Burma, and China. To date, no mitochondrial genomes of the genus Zoodes have been reported. In this study, we sequenced and analyzed the first mitochondrial genome of Z. fulguratus to discuss its phylogenetic relationship within the subfamily Cerambycinae. This mitochondrial genome showed the typical insect gene arrangement: a circular molecule of 15,885 bp long with 13 protein-coding genes, two ribosomal RNA genes (rRNAs), and 22 transfer RNA genes (tRNAs). The AT content of the whole mitogenome was 74.2% with a high asymmetric nucleotide presentation revealed by a positive AT-skew (0.067) and a negative GC-skew (–0.178), whereas the AT content of the A + T rich region was 80%. The Maximum likelihood (ML) and Bayesian inference (BI) phylogenetic analyses showed that Z. fulguratus is a sister clade of Gnatholea eburifera. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Pedetontus zhejiangensis (Microcoryphia: Machilidae) was successfully sequenced. The mitochondrial genome of P. zhejiangensis was a circular molecule of 15,602 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and the control region, which showed the typical insect mitochondrial genome arrangement. The AT content of the whole genome was 73.8% and the length of the control region was 671 bp with 82.5% AT content. In BI and ML phylogenetic trees, P. zhejiangensis was a sister group to Pedetontus silvestrii, and the monophyly of Pedetontus was strongly supported. The genus Pedetontinus was a sister group to Pedetontus. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Mantis religiosa (Mantodea: Mantidae) from Canada was successfully sequenced. The mitochondrial genome was a circular molecule of 15,521 bp in length, containing 13 protein-coding genes, two rRNA genes, 23 tRNA genes (including an extra tRNAArg gene), and the control region. The AT content of the whole genome was 76.9% and the length of the control region was 636 bp with 81.9% AT content. The structure of the M. religiosa mitochondrial genome from Canada was almost identical to M. religiosa from China and their genetic distance was just 0.017. In Bayesian inference (BI) and maximum likelihood (ML) analyses, we found that M. religiosa was a sister clade to Statilia sp. and the monophyly of the genera Hierodula and Rhombodera was not supported. [ABSTRACT FROM AUTHOR]

The phylogenetic relationship between Ephemeroptera (mayflies) and Odonata (dragonflies and damselflies) remains hotly debated in the insect evolution community. We sequenced the complete mitochondrial genome of Caenis sp. (Ephemeroptera: Caenidae) to discuss the phylogenetic relationship of Palaeoptera. The mitochondrial genome of Caenis sp. is a circular molecule of 15,254 bp in length containing 37 genes (13 protein-coding genes, 22 tRNAs, and 2 rRNAs), which showed the typical insect mitochondrial gene arrangement. In BI and ML phylogenetic trees using 71 species of 12 orders, our results support the Ephemeroptera as the basal group of winged insects. [ABSTRACT FROM AUTHOR]

The mitochondrial genome of Fejervarya kawamurai is a circular molecule of 17,650 bp in length, containing 13 protein-coding genes, two rRNA genes, 23 tRNA genes (including an extra tRNA-Met), and the control region. The AT content of the whole genome is 56.9%. In Bayesian inference (BI) and Maximum likelihood (ML) analyses, we found that F. kawamurai is a sister clade to F. multistriata and F. limnocharis. The monophyly of Fejervarya, Quasipaa, Nanorana was well supported (1.00 in BI and 100% in ML). [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Choroterpides apiculata (Ephemeroptera: Leptophlebiidae) is typically a circular molecule of 15,199 bp in length, containing 37 genes (13 protein-coding genes, 22 tRNAs, and two rRNAs) and one control region. The overall A + T content of the whole genome is 74% and the A + T content of the control region is 79.7%. In Bayesian inference and maximum-likelihood phylogenetic trees using 24 species from 13 families of Ephemeroptera, the monophyly of the families Isonychiidae, Heptageniidae, Vietnamellidae, Leptophlebiidae, Caenidae, and Baetidae were highly supported and C. apiculata was a sister group to Habrophlebiodes zijinensis. [ABSTRACT FROM AUTHOR]

Simple Summary: The family Scarabaeidae is one of the largest families in the insect order Coleoptera and is comprised of two quasi-systematics groups, Pleurosticti and Laparosticti. Pleurosticti is an economically important scarab group comprising about 20,000 species, the majority of which are phytophagous. Despite the innumerable studies based on ecological, molecular, and morphological characteristics, their taxonomy is still unclear and subject to many scientific hypotheses. The mitochondrial (mt) genome can provide tangible information to resolve the phylogenetic relationships within the family Scarabaeidae. However, the available mt genomes of Scarabaeidae in GenBank are underrepresented. Thus, we sequenced and analyzed 18 new phytophagous Scarabaeidae mitochondrial genomes from two subfamilies, Cetoniinae and Dynastinae, to conduct phylogenetic analyses within Scarabaeidae. This study contributes to increasing our knowledge about phytophagous Scarabaeidae. The availability of next-generation sequencing (NGS) in recent years has facilitated a revolution in the availability of mitochondrial (mt) genome sequences. The mt genome is a powerful tool for comparative studies and resolving the phylogenetic relationships among insect lineages. The mt genomes of phytophagous scarabs of the subfamilies Cetoniinae and Dynastinae were under-represented in GenBank. Previous research found that the subfamily Rutelinae was recovered as a paraphyletic group because the few representatives of the subfamily Dynastinae clustered into Rutelinae, but the subfamily position of Dynastinae was still unclear. In the present study, we sequenced 18 mt genomes from Dynastinae and Cetoniinae using next-generation sequencing (NGS) to re-assess the phylogenetic relationships within Scarabaeidae. All sequenced mt genomes contained 37 sets of genes (13 protein-coding genes, 22 tRNAs, and two ribosomal RNAs), with one long control region, but the gene order was not the same between Cetoniinae and Dynastinae species. All mt genomes of Dynastinae species showed the same gene rearrangement of trnQ-NCR-trnI-trnM, whereas all mt genomes of Cetoniinae species showed the ancestral insect gene order of trnI-trnQ-trnM. Phylogenetic analyses (IQ-tree and MrBayes) were conducted using 13 protein-coding genes based on nucleotide and amino acid datasets. In the ML and BI trees, we recovered the monophyly of Rutelinae, Cetoniinae, Dynastinae, and Sericinae, and the non-monophyly of Melolonthinae. Cetoniinae was shown to be a sister clade to (Dynastinae + Rutelinae). [ABSTRACT FROM AUTHOR]

The phylogenetic relationship of Caenidae remains hotly debated within the Ephemeroptera. We sequenced the complete mitochondrial genome of Caenis sp. (Ephemeroptera: Caenidae) to discuss the phylogenetic relationships among the Caenidae. The mitochondrial genome of Caenis sp. collected from Jian'ou, Fujian province, China is a circular molecule of 15,392 bp in length containing 37 genes (13 protein-coding genes, 22 tRNAs, and two rRNAs), which showed the typical insect mitochondrial gene arrangement. In BI and ML phylogenetic trees using 23 species from 13 families, the monophyly of the families Caenidae, Heptageniidae, Isonychiidae, and Vietnamellidae was strongly supported. The clade of Caenidae is a sister clade to the clade of Teloganodidae and Baetidae. [ABSTRACT FROM AUTHOR]

Simple Summary: Twenty-seven complete mitochondrial genomes of Phasmatodea have been published in the NCBI. To shed light on the intra-ordinal and inter-ordinal relationships among Phasmatodea, more mitochondrial genomes of stick insects are used to explore mitogenome structures and clarify the disputes regarding the phylogenetic relationships among Phasmatodea. We sequence and annotate the first acquired complete mitochondrial genome from the family Pseudophasmatidae (Peruphasma schultei), the first reported mitochondrial genome from the genus Phryganistria of Phasmatidae (P. guangxiensis), and the complete mitochondrial genome of Orestes guangxiensis belonging to the family Heteropterygidae. We analyze the gene composition and the structure of the three mitochondrial genomes. We recover the monophyly of Phasmatodea and show the sister-group relationship between Phasmatodea and Mantophasmatodea after removal of the Embioptera and Zoraptera species. We recover the monophyly of Heteropterygidae and the paraphyly of Diapheromeridae, Phasmatidae, Lonchodidae, Lonchodinae, and Clitumninae. Insects of the order Phasmatodea are mainly distributed in the tropics and subtropics and are best known for their remarkable camouflage as plants. In this study, we sequenced three complete mitochondrial genomes from three different families: Orestes guangxiensis, Peruphasma schultei, and Phryganistria guangxiensis. The lengths of the three mitochondrial genomes were 15,896 bp, 16,869 bp, and 17,005 bp, respectively, and the gene composition and structure of the three stick insects were identical to those of the most recent common ancestor of insects. The phylogenetic relationships among stick insects have been chaotic for a long time. In order to discuss the intra- and inter-ordinal relationship of Phasmatodea, we used the 13 protein-coding genes (PCGs) of 85 species for maximum likelihood (ML) and Bayesian inference (BI) analyses. Results showed that the internal topological structure of Phasmatodea had a few differences in both ML and BI trees and long-branch attraction (LBA) appeared between Embioptera and Zoraptera, which led to a non-monophyletic Phasmatodea. Consequently, after removal of the Embioptera and Zoraptera species, we re-performed ML and BI analyses with the remaining 81 species, which showed identical topology except for the position of Tectarchus ovobessus (Phasmatodea). We recovered the monophyly of Phasmatodea and the sister-group relationship between Phasmatodea and Mantophasmatodea. Our analyses also recovered the monophyly of Heteropterygidae and the paraphyly of Diapheromeridae, Phasmatidae, Lonchodidae, Lonchodinae, and Clitumninae. In this study, Peruphasma schultei (Pseudophasmatidae), Phraortes sp. YW-2014 (Lonchodidae), and species of Diapheromeridae clustered into the clade of Phasmatidae. Within Heteropterygidae, O. guangxiensis was the sister clade to O. mouhotii belonging to Dataminae, and the relationship of (Heteropteryginae + (Dataminae + Obriminae)) was recovered. [ABSTRACT FROM AUTHOR]

Simple Summary: The longicorn beetle, Monochamus alternatus, is a major vector for the transmission of pine wilt disease, which is caused by a nematode pathogen, Bursaphelenchus xylophilus (or also possibly by B. mucronatus) that is spread by the beetle as it feeds on pine trees. In this study, the mitochondrial genome sequences of four longicorn species (Coleoptera: Cerambycidae: Lamiinae) were determined to further elaborate the phylogenetic relationships of Lamiinae. RT-qPCR was also used to assess the expression of eight mitochondrial protein-coding genes in M. alternatus when carrying B. mucronatus or not, so as to explore the relationship between these two species. The results showed that expression of mitochondria-encoded genes was elevated in M. alternatus beetles that were infected with B. mucronatus, suggesting that B. mucronatus putatively activates an immune response, which significantly affects the metabolic processes of M. alternatus. These results are of significance for further understanding the phylogenetic relationships of longicorn beetles and controlling the spread of pine wilt disease. We determined the mitochondrial gene sequence of Monochamus alternatus and three other mitogenomes of Lamiinae (Insect: Coleoptera: Cerambycidae) belonging to three genera (Aulaconotus, Apriona and Paraglenea) to enrich the mitochondrial genome database of Lamiinae and further explore the phylogenetic relationships within the subfamily. Phylogenetic trees of the Lamiinae were built using the Bayesian inference (BI) and maximum likelihood (ML) methods and the monophyly of Monochamus, Anoplophora, and Batocera genera was supported. Anoplophora chinensis, An. glabripennis and Aristobia reticulator were closely related, suggesting they may also be potential vectors for the transmission of the pine wood pathogenic nematode (Bursaphelenchus xylophilus) in addition to M. alternatus, a well-known vector of pine wilt disease. There is a special symbiotic relationship between M. alternatus and Bursaphelenchus xylophilus. As the native sympatric sibling species of B. xylophilus, B. mucronatus also has a specific relationship that is often overlooked. The analysis of mitochondrial gene expression aimed to explore the effect of B. mucronatus on the energy metabolism of the respiratory chain of M. alternatus adults. Using RT-qPCR, we determined and analyzed the expression of eight mitochondrial protein-coding genes (COI, COII, COIII, ND1, ND4, ND5, ATP6, and Cty b) between M. alternatus infected by B. mucronatus and M. alternatus without the nematode. Expression of all the eight mitochondrial genes were up-regulated, particularly the ND4 and ND5 gene, which were up-regulated by 4–5-fold (p < 0.01). Since longicorn beetles have immune responses to nematodes, we believe that their relationship should not be viewed as symbiotic, but classed as parasitic. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Isonychia kiangsinensis is a circular molecule of 15,456 bp in length, containing 2 rRNA genes, 13 protein-coding genes, 22 tRNA genes, and a control region. The AT content of the overall base composition is 62.9%. The length of the control region for I. kiangsinensis is 745 bp with 68.6% AT content. In BI and ML phylogenetic trees, Isonychia kiangsinensis was a sister clade to I. ignota and Isonychiidae was shown to be the basal clade of Ephemeroptera excluding Siphluriscidae. The monophyly of the families Isonychiidae, Heptageniidae, Viemamellidae, and Baetidae and the genus Isonychia were well supported. [ABSTRACT FROM AUTHOR]

The mitochondrial genome of Epeorus herklotsi (Ephemeroptera: Heptageniidae) is a circular molecule of 15,801 bp in length with a base composition of 32.7% A, 32.9% T, 21.5% C, 13.0% G, including extra tRNAMet gene. The IMQM tRNA cluster is found in E. herklotsi as well as Parafornuru youi and two species of Epeorus (KM244708, KJ493406), while the typical IQM tRNA cluster is found in Paegniodes cupulatus. In BI and ML phylogenetic trees, the monophyly of the families Heptageniidae, Baetidae, and Ephemerellidae are highly supported. E. herklotsi is a sister clade to Epeorus sp2. (KJ493406). [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome sequence of the hybrid of Hoplobatrachus chinensis (♀) × H. rugulosus (♂) was obtained in this study. The circular mitochondrial genome was 20,282 bp in length (including extra ND5 genes). Compared with the complete mitogenome of the parents, the results indicated that the mitochondria of the hybrid tiger frog was consistent with a maternal inheritance. Phylogenetic analyses using concatenated nucleotide sequences of the 11 protein-coding genes with two different methods (maximum likelihood and MrBayes analysis) both highly supported a close relationship of the hybrid frogs with the Chinese tiger frog (=H. chinensis). [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Psychomantis borneensis (Mantodea: Hymenopodidae) was successfully sequenced. The mitochondrial genome is found to be 15,493 bp long and is a circular molecule containing 37 genes (13 protein-coding genes, 22 tRNAs, and 2 rRNAs), typically found in other mantis mitochondrial genomes. The AT content of the whole genome was 72.4% and the length of the control region was 697 bp with 79.9% AT content. A phylogenetic tree was constructed based on the BI and ML analysis of 16 species of Mantodea. The results showed that P. borneensis was a sister clade to (Anaxarcha zhengi + Creobroter gemmata) (Hymenopodidae). The monophyly of the family Mantidae and the genus Theopompa, Hierodula, and Rhombodera were not supported. The outcome of this study will provide a useful data for population genetics studies as well as serve as a tool for better characterizing phylogenetic analysis of Mantodea. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of the thirteen-lined ground squirrel,Ictidomys tridecemlineatus(Rodentia: Sciuridae) was sequenced to analyze the gene arrangement. It is a circular molecule of 16,458 bp in length including 37 genes typically found in other squirrels. The AT content of the overall base composition is 63.7% and the length of the control region is 1016 bp with 63.0% AT content. In BI and ML phylogenetic trees,I. tridecemlineatusis a sister clade to the genusCynomys, andTamias sibiricusis a sister clade to (Marmota himalayana + (I. tridecemlineatus + (C. leucurus + C. ludovicianus))). Ratufinae is well supported as the basal clade of Sciuridae. The monophyly of the family Sciuridae and its subfamilies Callosciurinae, Xerinae and Sciurinae are well supported. [ABSTRACT FROM AUTHOR]

Background: Complete mitochondrial (mt) genomes have been used extensively to test hypotheses about microevolution and to study population structure, phylogeography, and phylogenetic relationships of Anura at various taxonomic levels. Large-scale mt genomic reorganizations have been observed among many fork-tongued frogs (family Dicroglossidae). The relationships among Dicroglossidae and validation of the genus Feirana are still problematic. Hence, we sequenced the complete mt genomes of Nanorana taihangnica (=F. taihangnica) and N. yunnanensis as well as partial mt genomes of six Quasipaa species (dicroglossid taxa), two Odorrana and two Amolops species (Ranidae), and one Rhacophorus species (Rhacophoridae) in order to identify unknown mt gene rearrangements, to investigate the validity of the genus Feirana, and to test the phylogenetic relationship of Dicroglossidae. Results: In the mt genome of N. taihangnica two trnM genes, two trnP genes and two control regions were found. In addition, the trnA, trnN, trnC, and trnQ genes were translocated from their typical positions. In the mt genome of N. yunnanensis, three control regions were found and eight genes (ND6, trnP, trnQ, trnA, trnN, trnC, trnY and trnS genes) in the L-stand were translocated from their typical position and grouped together. We also found intraspecific rearrangement of the mitochondrial genomes in N. taihangnica and Quasipaa boulengeri. In phylogenetic trees, the genus Feirana nested deeply within the clade of genus Nanorana, indicating that the genus Feirana may be a synonym to Nanorana. Ranidae as a sister clade to Dicroglossidae and the clade of (Ranidae + Dicroglossidae) as a sister clade to (Mantellidae + Rhacophoridae) were well supported in BI analysis but low bootstrap in ML analysis. Conclusions: We found that the gene arrangements of N. taihangnica and N. yunnanensis differed from other published dicroglossid mt genomes. The gene arrangements in N. taihangnica and N. yunnanensis could be explained by the Tandem Duplication and Random Loss (TDRL) and the Dimer-Mitogenome and Non-Random Loss (DMNR) models, respectively. The invalidation of the genus Feirana is supported in this study. [ABSTRACT FROM AUTHOR]

Abstract Different mitochondrial gene copies or gene rearrangements are observed in some interspecific mitochondrial genomes (mitogenomes), but few in intraspecific mitogenomes. In this study, we sequenced the complete mitogenomes of Statilia maculata and Statilia nemoralis (Mantinae: Mantini). The genetic distance of the whole genomes between these two species was just 0.5%, suggesting that S. maculata and S. nemoralis might be the same species. The mitogenome of S. maculata had five copies of trnR genes (three copies were identical and the other two had some base substitutions), whereas the mitogenome of S. nemoralis had six trnR genes. Five, six or seven tandem copies of trnR genes in S. maculata were found in different localities, respectively. We further sequenced the ND3 - ND5 region of fifty individuals hatched from one ootheca (Tianjin) and we found that all individuals had five identical tandem copies of trnR genes and same sequences. Hence, we concluded that different copies of trnR genes can occur in the same species. The mitogenomes of S. maculata and S. nemoralis with other mitogenomes of Mantinae species published were used to construct BI and ML phylogenetic trees. In this study, both BI and ML phylogenetic trees showed that Mantini and Statilia were monophyletic whereas Paramantini was paraphyletic. [ABSTRACT FROM AUTHOR]

• The genomes of Acanthopoidea and Galinthiadoidea species were firstly reported. • Two novel gene rearrangements of ND3-A-R-N-S-E-F and COX1-L2-COX2 in Mantodea were found. • The monophyly of Acanthopoidea was supported by ML and BI trees. The mitochondrial genome (mitogenome) plays an important role in phylogenetic studies of many species. The mitogenomes of many praying mantis groups have been well-studied, but mitogenomes of special mimic praying mantises, especially Acanthopoidea and Galinthiadoidea species, are still sorely lacking in the NCBI database. The present study analyzes five mitogenomes from four species of Acanthopoidea (Angela sp., Callibia diana , Coptopteryx sp., Raptrix fusca) and one of Galinthiadoidea (Galinthias amoena) that were sequenced by the primer-walking method. Among Angela sp. and Coptopteryx sp., three gene rearrangements were detected in ND3-A-R-N-S-E-F and COX1-L2-COX2 gene regions, two of which were novel. In addition, individual tandem repeats were found in control regions of four mitogenomes (Angela sp., C. diana , Coptopteryx sp., G. amoena). For those, plausible explanations were derived from the tandem duplication-random loss (TDRL) model and the slipped-strand mispairing model. One potential motif was found in Acanthopidae that was seen as a synapomorphy. Several conserved block sequences (CBSs) were detected within Acanthopoidea that paved the way for the design of specific primers. Via BI and ML analysis, based on four datasets (PCG12, PCG12R, PCG123, PCG123R), the merged phylogenetic tree within Mantodea was reconstructed. This showed that the monophyly of Acanthopoidea was supported and that the PCG12R dataset was the most suitable for reconstructing the phylogenetic tree within Mantodea. [ABSTRACT FROM AUTHOR]

Three complete mitochondrial genomes of Blaberidae (Insecta: Blattodea) ( Gromphadorhina portentosa , Panchlora nivea , Blaptica dubia ) and one complete mt genome of Blattidae (Insecta: Blattodea) ( Shelfordella lateralis ) were sequenced to further understand the characteristics of cockroach mitogenomes and reconstruct the phylogenetic relationship of Blattodea. The gene order and orientation of these four cockroach genomes were similar to known cockroach mt genomes, and contained 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and one control region. The mt genomes of Blattodea exhibited a characteristics of a high A + T composition (70.7%–74.3%) and dominant usage of the TAA stop codon. The AT content of the whole mt genome, PCGs and total tRNAs in G. portentosa was the lowest in known cockroaches. The presence of a 71-bp intergenic spacer region between trnQ and trnM was a unique feature in B. dubia , but absent in other cockroaches, which can be explained by the duplication/random loss model. Based on the nucleotide and amino acid datasets of the 13 PCGs genes, neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and bayesian inference (BI) analyses were used to rebuild the phylogenetic relationship of cockroaches. All phylogenetic analyses consistently placed Isoptera as the sister cluster to Cryptocercidae of Blattodea. Ectobiidae and Blaberidae (Blaberoidea) formed a sister clade to Blattidae. Corydiidae is a sister clade of all the remaining cockroach species with a high value in NJ and MP analyses of nucleotide and amino acid datasets, and ML and BI analyses of the amino acid dataset. [ABSTRACT FROM AUTHOR]

• The complete mitochondrial genome of C. yixingensis was sequenced for the first time. • The steady state transcript levels of mitochondrial COX3 , ND4 and ND4L genes were reduced under 40 μg/L imidacloprid for 24 h. • Steady state transcript levels of ND4 and ND4L were also significantly reduced under different concentrations. As one of the most common benthic invertebrates in freshwater, mayflies are very sensitive to changes in water quality and have high requirements for the water environment to allow their nymphs to successfully live and grow. Neonicotinoids, such as imidacloprid, can enter fresh water and pollute the aquatic environment. The present study had two goals: (1) investigate imidacloprid effects on mayfly larvae Choroterpes (Euthralus) yixingensis , and (2) contribute to the phylogenetic status of Ephemeroptera that has always been controversial. Nymphs were collected from Jinhua, China and exposed to different concentrations imidacloprid (5, 10, 20, and 40 μg/L) in the laboratory. Survival of C. yixingensis nymphs decreased as a function of time and imidacloprid concentration with only ~ 55% survival after 72 h exposure to 40 μg/L imidacloprid. After culture under 40 μg/L imidacloprid for 24 h, the steady state transcript levels of mitochondrial COX3 , ND4 and ND4L genes were reduced to just 0.07 ± 0.11, 0.30 ± 0.16, and 0.28 ± 0.13 as compared with respective control values (P < 0.01). Steady state transcript levels of ND4 and ND4L were also significantly reduced in a dose-dependent manner (P < 0.05), suggesting that the steady state transcript pattern of these genes in mayfly nymphs can change in response to different levels of environmental contamination. Hence, the mitochondrial protein-coding genes of mayflies could potentially be developed as biomarkers for water ecotoxicity monitoring in the future. In addition, we used the mitochondrial genome sequence of C. yixingensis for an assessment of the phylogenetic tree of Ephemeroptera. The monophyly of Leptophlebiidae was supported and showed that Leptophlebiidae was a sister group to the clade (Baetidae + Caenidae). [ABSTRACT FROM AUTHOR]