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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. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Gene rearrangements have been found in several mitochondrial genomes of Mantodea, located in the gene blocks CR- I-Q-M-ND2 , COX1 - K - D - ATP8 and ND3-A-R-N-S-E-F-ND5. We have sequenced one mitogenome of Amelidae (Yersinia mexicana) and six mitogenomes of Mantidae to discuss the mitochondrial gene rearrangement and the phylogenetic relationship within Mantidae. These mitogenomes showed rearrangements of tRNA genes except for Asiadodis yunnanensis and Hierodula zhangi. These novel gene rearrangements of Mantidae were primarily concentrated in the region of CR- I-Q-M-ND2 , including gene translocation, duplication and pseudogenization. For the occurrences of these rearrangements, the tandem duplication-random loss (TDRL) model and slipped-strand mispairing model were suitable to explain. Large non-coding regions (LNCRs) located in the region of CR- I-Q-M-ND2 were detected in most Mantidae species, whereas some LNCRs had high similarity to the control region (CR). Both BI and ML phylogenetic analyses supported the monophyly of Mantidae and the paraphyly of Mantinae. The phylogenetic results with the gene order and the location of NCRs acted as forceful evidence that specific gene rearrangements and special LNCRs may be synapomorphies for several groups of mantises. [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]

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. [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]