Complete mitochondrial genome of Chilo suppressalis (Walker) (Lepidoptera: Crambidae)

The complete sequence of the mitochondrial genome (mitogenome) of the rice stem borer Chilo suppressalis (Walker) (Lepidoptera: Crambidae) was determined to be 15,465 bp. It contains 13 protein-coding genes (PCGs), 22 tRNA genes, the large and small rRNA genes, and an A+T-rich region. The nucleotide composition of the mitogenome of C. suppressalis is highly A+T biased, accounting for 79.70% in whole mitogenome, 77.74% in PCGs, 84.70% in tRNAs, 81.20% in rRNAs and 94.19% in A+T-rich region, respectively. The PCGs have typical ATN start codons, except for cox1, which contains the unusual CGA. The C. suppressalis A+T-rich region contains a conserved structure combining the motif ATAGA and a 19-bp poly-T stretch, but absence of the 9-bp poly-A element upstream trnM.     

Complete mitochondrial genome of the nerippe fritillary butterfly, Argynnis nerippe (Lepidoptera: Nymphalidae)

The complete mitochondrial genome sequence of the nerippe fritillary butterfly, Argynnis nerippe, which is listed as an endangered species in Korea, is described with an emphasis on the A+T-rich region. The 15,140-bp long circular molecule consisted of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and 1 control region, known in insect as the A+T-rich region, as found in typical metazoans. The 329-bp long A+T-rich region located between srRNA and tRNA(Met) possessed the highest A/T content (95.7%) than any other region of the genome. Along with the several conserved sequences found typically in the lepidopteran insects the genome contained one tRNA(Met)-like and tRNA(Leu)(UUR)-like sequence in the A+T-rich region.     

The complete mitochondrial genome of fall armyworm <Emphasis Type="Italic">Spodoptera frugiperda</Emphasis> (Lepidoptera:Noctuidae)

The mitochondrial genome (mitogenome) can provide important information for understanding molecular evolution and phylogenetic analyses. The complete mitogenome of Spodoptera frugiperda (Lepidoptera:Noctuidae) was determined to be 15,365 bp in length and has the typical gene order found in Noctuidae mitogenomes, it includes 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a A+T-rich region. The nucleotide composition was biased toward A+T nucleotides (81.09 %) and the AT skew of this mitogenome was slightly positive (0.004). All PCGs were initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene which was initiated by CGA. Eight of the 13 PCGs have the incomplete termination codon, T or TA. All the tRNA genes displayed the typical clover-leaf structure of mitochondrial tRNAs, with the exception of trnS1 (AGN). The A+T-rich region was 328 bp in length and consisted of several features common to the Noctuidae insects. Phylogenetic analysis showed that the S. frugiperda was within the Noctuidae.     

斐豹蛱蝶线粒体基因组全序列的测定和分析(英文)

该研究对斐豹蛱蝶(Argyreus hyperbius)(鳞翅目:蛱蝶科)线粒体基因组全序列进行了测定和初步分析。结果表明:斐豹蛱蝶线粒体基因全序列全长为15156bp,包含13个蛋白质编码基因、22个tRNA和2个rRNA基因以及1个非编码的A+T富集区,基因排列顺序与其它鳞翅目种类一致;线粒体全序列核苷酸组成和密码子使用显示出明显的A+T偏好(80.8%)和轻微的AT偏移(AT skew,?0.019)。基因组中共存在11个2～52bp不等的基因间隔区,总长96bp;以及14个1～8bp不等的基因重叠区,总长34bp。除COI以CGA作为起始密码子外,13个蛋白质编码基因中的其余12个基因是以ATN作为起始密码子。除COI和COII基因是以单独的一个T为终止密码子,其余11个蛋白质编码基因都是以TAA结尾的。除了缺少DHU臂的tRNASer(AGN),其余的tRNA基因都显示典型的三叶草结构。tRNA(AGN)和ND1之间的基因间隔区包含一个ATACTAA结构域,这个结构域在鳞翅目中是保守的。A+T富集区没有较大的多拷贝重复序列,但是包含一些微小重复结构:ATAGA结构域下游的20bp poly-T结构,ATTTA结构域后的(AT)9重复,以及位于tRNAMet上游的5bp poly-A结构等。这项研究所揭示的斐豹蛱蝶的线粒体基因组特征,不仅为认识蛱蝶科的遗传多样性贡献数据,而且对于该物种的保护生物学、群体遗传学、谱系地理及演化研究等具有重要意义。     

The complete mitochondrial genome of the wild silkworm moth, Actias selene

The complete mitochondrial genome (mitogenome) of Actias selene (Lepidoptera: Saturniidae) was determined to be 15,236 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a control region. The arrangement of 13 PCGs was similar to that of other sequenced lepidopterans. The AT skew of the mitogenome of A. selene was slightly negative, indicating a higher number of T compared to A nucleotides. The nucleotide composition of the mitogenome of A. selene was also biased toward A+T nucleotides (78.91%). All PCGs were initiated by ATN codons, except for the gene encoding cytochrome c oxidase subunit 1 (cox1), which may be initiated by the TTAG, as observed in other lepidopterans. Three genes, including cox1, cox2, and nad5, had incomplete stop codons consisting of just a T. With an exception for trnS1(AGN), all the other tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A+T-rich region of the mitogenome of A. selene was 339 bp in length, and contains several features common to the Lepidopteras, including non-repetitive sequences, a conserved structure combining the motif ATAGA and an 18-bp poly-T stretch and a poly-A element upstream of trnM gene. Phylogenetic analysis showed that A. selene was close to Saturniidae.     

Characterization of the complete mitochondrial genome of Diaphania pyloalis (Lepidoptera: Pyralididae)

The complete mitochondrial genome (mitogenome) of Diaphania pyloalis (Lepidoptera: Pyralididae) was determined to be 15,298 bp and has the typical gene organization of mitogenomes from lepidopteran insects. It consists of 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and an A + T-rich region. The A + T content of this mitogenome is 80.83% and the AT skew is slightly positive. All PCGs are initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene which is initiated by CGA. Only the cox2 gene has an incomplete stop codon consisting of just a T. All the tRNA genes display a typical clover-leaf structure of mitochondrial tRNA. The A + T-rich region of the mitogenome is 332 bp in length, including several common features found in lepidopteran mitogenomes. Phylogenetic analysis showed that the D. pyloalis is close to Pyralididae.     

残锷线蛱蝶线粒体基因组全序列及其系统学意义(英文)

对残锷线蛱蝶(Parathymasulpitia)(鳞翅目:蛱蝶科)线粒体基因组全序列进行了测定。结果表明:残锷线蛱蝶线粒体基因组全序列全长为15268bp,除了在trnS1(AGN)和trnE基因之间有一段121bp长的基因间隔外,其基因的排列顺序及排列方向与大多数已测鳞翅目物种基本一致。在蛋白质编码基因中,除cox1以CGA作为其起始密码子之外,其余12个蛋白质编码基因都以标准的ATN作为起始密码子。此外,除nad4基因以单独的T为终止密码子,其余12个蛋白质编码基因都以TAA结尾。除trnS1(AGN)缺少DHU臂之外,22个tRNA基因都显示典型的三叶草形二级结构。除A+T富集区外的非编码序列中,线粒体基因组共含有11个基因间隔区。其中,最长的一个121bp的基因间隔区位于trnS1(AGN)和trnE之间,其A+T含量高达100%。另外,和其他鳞翅目物种一样,在其A+T富集区的3’端有一段长达18bp的poly-T结构。A+T富集区内部没有明显的小卫星样多拷贝重复序列,而含有一些微卫星样的重复结构。本研究基于13种蛋白编码基因序列的组合数据,用最大似然法和贝叶斯法对蛱蝶科几个主要亚科间共9个代表物种间的系统发生关系进行了分析。结果表明,本研究的结果与前人的分子系统学研究结论基本吻合(其中,线蛱蝶亚科和釉蛱蝶亚科互为姐妹群),而与形态学的研究结论不一致。     

Characterization of the complete mitochondrial genomes of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae)

The complete mitochondrial genomes (mitogenomes) of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae) were determined and analyzed. The circular genomes were 15,388 bp long for C. medinalis and 15,395 bp long for C. suppressalis. Both mitogenomes contained 37 genes, with gene order similar to that of other lepidopterans. Notably, 12 protein-coding genes (PCGs) utilized the standard ATN, but the cox1 gene used CGA as the initiation codon; the cox1, cox2, and nad4 genes in the two mitogenomes had the truncated termination codons T, T, and TA, respectively, but the nad5 gene was found to use T as the termination codon only in the C. medinalis mitogenome. Additionally, the codon distribution and Relative Synonymous Codon Usage of the 13 PCGs in the C. medinalis mitogenome were very different from those in other pyralid moth mitogenomes. Most of the tRNA genes had typical cloverleaf secondary structures. However, the dihydrouridine (DHU) arm of the trnS1(AGN) gene did not form a stable stem-loop structure. Forty-nine helices in six domains, and 33 helices in three domains were present in the secondary structures of the rrnL and rrnS genes of the two mitogenomes, respectively. There were four major intergenic spacers, except for the A+T-rich region, spanning at least 12 bp in the two mitogenomes. The A+T-rich region contained an 'ATAGT(A)'-like motif followed by a poly-T stretch in the two mitogenomes. In addition, there were a potential stem-loop structure, a duplicated 25-bp repeat element, and a microsatellite '(TA)(13)' observed in the A+T-rich region of the C. medinalis mitogenome. A poly-T motif, a duplicated 31-bp repeat element, and a 19-bp triplication were found in the C. suppressalis mitogenome. However, there are many differences in the A+T-rich regions between the C. suppressalis mitogenome sequence in the present study and previous reports. Finally, the phylogenetic relationships of these insects were reconstructed based on amino acid sequences of mitochondrial 13 PCGs using Bayesian inference and maximum likelihood methods. These molecular-based phylogenies support the traditional morphologically based view of relationships within the Pyralidae.     

Complete mitochondrial genomes of two green lacewings, <Emphasis Type="Italic">Chrysoperla nipponensis</Emphasis> (Okamoto, 1914) and <Emphasis Type="Italic">Apochrysa matsumurae</Emphasis> Okamoto, 1912 (Neuroptera: Chrysopidae)

We describe the complete mitochondrial genomes of the green lacewing species Chrysoperla nipponensis (Okamoto, 1914) and Apochrysa matsumurae Okamoto 1912 (Neuroptera: Chrysopidae). The genomes were 16,057 and 16,214 bp in size, respectively, and comprised 37 genes (13 protein coding genes, 22 tRNA genes and two rRNA genes). A major noncoding (control) region was 1,244 bp in C. nipponensis and 1,407 in A. matsumurae, and the structure was simpler than that reported in other Neuroptera, lacking conserved blocks or long tandem repeats. The overall arrangement of genes was almost the same as that found in most arthropod mitochondrial genomes, with the one exception of a tRNA rearrangement to tRNA-Cys–tRNA-Trp–tRNA-Tyr, rather than the plesiomorphic tRNA-Trp–tRNA-Cys–tRNA-Tyr. A high A + T content (78.89 and 79.02%, respectively), A + T-rich codon bias, and a mismatch between the most-used codon and its corresponding tRNA anticodon were observed as a typical feature of the insect mitochondrial genome.     

The Complete Mitochondrial Genome of the Stalk-Eyed Bug Chauliops fallax Scott,and the Monophyly of Malcidae (Hemiptera: Heteroptera)

Chauliops fallax Scott, 1874 (Hemiptera: Heteroptera: Malcidae: Chauliopinae) is one of the most destructive insect pests of soybean and rice fields in Asia. Here we sequenced the complete mitochondrial genome of this pest. This genome is 15,739 bp long, with an A+T content of 73.7%, containing 37 typical animal mitochondrial genes and a control region. All genes were arranged in the same order as most of other Heteroptera. A remarkable strand bias was found for all nine protein coding genes (PCGs) encoded by the majority strand were positive AT-skew and negative GC-skew, whereas the reverse were found in the remaining four PCGs encoded by the minority strand and two rRNA genes. The models of secondary structures for the two rRNA genes of sequenced true bugs and Lygaeoidea were predicted. 16S rRNA consisted of six domains (domain III is absent as in other known arthropod mitochondrial genomes) and 45 helices, while three domains and 27 helices for 12S rRNA. The control region consists of five subregions: a microsatellite-like region, a tandem repeats region and other three motifs. The unusual intergenic spacer between tRNA-H and ND4 only found in the species of Lygaeoidea, not in other heteropteran species, may be the synapomorphy of this superfamily. Phylogenetic analyses were carried out based on all the 13 PCGs showed that Chauliopinae was the sister group of Malcinae and the monophyly of Lygaeoidea.     

The complete mitochondrial genomes of two ghost moths, Thitarodes renzhiensis and Thitarodes yunnanensis: the ancestral gene arrangement in Lepidoptera

ABSTRACT: BACKGROUND: Lepidoptera encompasses more than 160,000 described species that have been classified into 45-48 superfamilies. The previously determined Lepidoptera mitochondrial genomes (mitogenomes) are limited to six superfamilies of the most derived lepidopteran lineage Ditrysia. Compared with the ancestral insect gene order, these mitogenomes all contain a tRNA rearrangement. To gain new insights into Lepidoptera mitogenome evolution, we sequenced the mitogenomes of two ghost moths that belong to primitive lepidopteran lineages and conducted a comparative mitogenomic analysis across Lepidoptera. RESULTS: The mitogenomes of Thitarodes renzhiensis and T. yunnanensis are 16,173 bp and 15,814 bp long with an A+T content of 81.28% and 82.33%, respectively. Different tandem repeats in the A+T-rich region mainly account for the size difference between the two mitogenomes. Both mitogenomes include 13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The 1,584-bp sequence from rrnS to nad2 was also determined for Thitarodes sp.QL, which has no repetitive sequence in the A+T-rich region. All three Thitarodes species possess the ancestral gene order with trnI-trnQ-trnM located between the A+T-rich region and nad2, which is different from the gene order trnM-trnI-trnQ in all previously sequenced Lepidoptera species. The formerly identified conserved elements of Lepidoptera mitogenomes (i.e. the motif 'ATAGA' and poly-T stretch in the A+T-rich region and the long intergenic spacer upstream of nad2) are absent in the Thitarodes mitogenomes. The phylogenetic analysis supports that Hepialoidea, represented by T. renzhiensis and T. yunnanensis, occupies a basal position in the currently sampled seven superfamilies. The relationships of the other six superfamilies are (((((Bombycoidea + Geometroidea) + Noctuoidea) + Pyraloidea) + Papilionoidea) + Tortricoidea). CONCLUSION: The mitogenomes of T. renzhiensis and T. yunnanensis exhibit unusual features compared with the previously determined Lepidoptera mitogenomes. Their ancestral gene order indicates that the tRNA rearrangement event occurred after Lepidoptera diverged from other holometabolous insect orders. Phylogenetic analysis based on mitogenome sequences is a power tool for addressing phylogenetic relationships among major Lepidoptera superfamilies. Characterization of the two ghost moth mitogenomes has enriched our knowledge of Lepidoptera mitogenomes and contributed to our understanding of the mechanisms underlying mitogenome evolution, especially gene rearrangements.     

Complete mitochondrial genome of Dacus conopsoides (Insecta: Tephritidae) with tRNA gene duplication and molecular phylogeny of Dacini tribe

To date there is only a single report on the complete mitochondrial genome of the Dacus fruit flies. We report here the whole mitogenome of Dacus conopsoides with first report of tRNA gene duplication in tephritid fruit flies determined using next-generation sequencing and discuss the molecular phylogeny of Dacini tribe. It had a total length of 15,852 bp, comprising 13 protein coding genes, 2 rRNA genes, 23 tRNA genes, and a non-coding region (A + T-rich control region). The 65-bp trnF gene was duplicated, and the 68-bp trnE gene was partially duplicated resulting in a 31-bp pseudogene. The cloverleaf structure for trnN, trnH, and trnF lacked the TΨC-loop, while trnS lacked the D-stem. The start codons for the protein coding genes included 6 ATG, 3 ATC, 2 ATA, and 1 each of ATT and TCG. Seven PCGs had TAA stop codon, two had TAG and four had incomplete T stop codon. Molecular phylogeny based on 15 mt-genes (13 PCGs +2 rRNA genes) and 30 taxa of Tephritidae indicated D. conopsoides forming a monophyletic sister group with D. longicornis supported by high bootstrap value. The lineage containing also the monophyletic genus Zeugodacus. The Dacini and Ceratitidini tribes of the subfamily Dacinae were monophyletic but the subfamilies Dacinae and Trypetinae were paraphyletic. A broader taxa sampling of the Tephritidae is needed to better elucidate the phylogenetics and systematics of the tribes and subfamilies of tephritid fruit flies.     

The complete mitochondrial genome of <Emphasis Type="Italic">Damora sagana</Emphasis> and phylogenetic analyses of the family Nymphalidae

The monotypic genus Damora (Nymphalidae, Heliconiinae) contains a single species, Damora sagana, which is widely distributed across southern China. Herein, its complete mitogenome was sequenced to further understand lepidopteran mitogenome characteristics, reconstruct the nymphalid family phylogeny, and infer the subdivision of Heliconiinae species. The circular mitogenome was 15,151 bp long, abundant in A and T, and comprised of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and one control region with a gene arrangement typical of lepidopteran mitogenomes. ATN codons initiated all PCGs, except cytochrome c oxidase subunit 1 (COX1), which was initiated by a CGA sequence as has been observed in other lepidopterans. Three PCGs (COX1, COX2 and ND4) employed a single T termination signal, whereas others had the typical complete termination codon (TAA). All tRNA genes were folded into the typical cloverleaf structure except for tRNA-Ser (AGN). The A+T-rich region included the conserved motif ‘ATAGA’ followed by a 17 bp poly-T stretch, which was also observed in tribe Argynnini mitogenomes. A phylogenetic tree was constructed via multiple methods using the 13 PCGs data of D. sagana and other available mitogenomes of nymphalid species. All three phylogenetic trees yielded the same topology. These results were consistent with those from previous studies of most major nymphalid groups, except those regarding tribe subdivision in certain subfamilies such as Argynnini + (Acraeini + Heliconiini) for Heliconiine. Furthermore, our analyses identified that the genus Cethosia was grouped with the genus Acraea composing the tribe Acraeini with strong support.     

The complete mitochondrial genome of the sycamore lace bug Corythucha ciliata (Hemiptera: Tingidae)

The complete mitochondrial genome of the sycamore lace bug, Corythucha ciliata, was sequenced in this study. It represents the first sequenced mitogenome of family Tingidae in Heteroptera. The mitogenome of C. ciliata is 15,257 bp and contains 37 genes including 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes and a large non-coding region. Gene arrangement, nucleotide content, codon usage, and amino acid composition and asymmetry indicate a high degree of conservation with six other species of Cimicomorpha. The 13 PCGs initiated with ATN as the start codon and terminated with TAA, TA or T as stop codon. The evolutionary rate of each PCG was different, among which ATP8 showed the highest rate while ATP6 indicated the lowest rate. The 22 tRNAs genes apparently fold into a typical cloverleaf structure; however, the anticodon (TTC) of trnSer (AGN) differs from other Heteropteran insects. Secondary structure modeling of rRNA genes revealed similarity to other insects, except for two incomplete helices (H1648 and H2735) in lrRNA. The predicted secondary structure of lrRNA indicates 45 helices in six domains, whereas srRNA has 27 helices in three domains. Three potential stem–loops and two tandem repeats (–TCTAAT–) were identified in the A+T-rich region. Phylogenetic analysis indicated that C. ciliata is a sister group to other Heteroptera species based on analysis of the 13 PCGs.     

Characterization of the complete mitochondrial genome of Bombyx mori strain H9 (Lepidoptera: Bombycidae)

The complete mitochondrial genome (mitogenome) of Bombyx mori strain H9 (Lepidoptera: Bombycidae) is 15,670 base pairs (bp) in length, encoding 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a control region. The nucleotide composition of the genome is highly A + T biased, accounting for 81.31%, with a slightly positive AT skewness (0.059). The arrangement of 13 PCGs is similar to that of other sequenced lepidopterans. All the PCGs are initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which is proposed by the TTAG sequence as observed in other lepidopterans. Unlike the other PCGs, the cox1 and cytochrome c oxidase subunit 2 (cox2) genes have incomplete stop codons consisting of just a T. All tRNAs have typical structures of insect mitochondrial tRNAs, which is different from other sequenced lepidopterans. The structure of A + T-rich region is similar to that of other sequenced lepidopterans, including non-repetitive sequences, the ATAGA binding domain, a 18 bp poly-T stretch and a poly-A element upstream of transfer RNA M (trnM) gene. Phylogenetic analysis shows that the domesticated silkmoth B. mori originated from the Chinese Bombyx mandarina.     

The complete mitochondrial genome of the leafminer <Emphasis Type="Italic">Liriomyza trifolii</Emphasis> (Diptera: Agromyzidae)

Liriomyza trifolii (Diptera: Agromyzidae) is one of the most economically significant pests in the world. In this paper we present sequence data for the complete mitochondrial genome of L. trifolii. The circular genome is 16,141 bp long and contains one encoding region including 37 genes and one non-coding A+T-rich region. Gene numbers and organization is similar to that of the typical insect mitochondrial genomes except that two additional tRNA genes are found in the A+T-rich region (tRNA^Thr and tRNA^Leu(UUR)). All of the protein initiation codons are ATN, except ND1 which begins with GTG and COI which is initiated by the quadruplet ATCA. The 22 tRNA anticodons of L. trifolii match those observed in Drosophila yakuba, and all of tRNAs form the typical cloverleaf structure except for tRNA^Ser(AGN), which has lost the DHU-arm. The A+T-rich region of L. trifolii also contains two previously noted Diperan features—a highly conserved polyT stretch and a (TA)_n stretch.     

武铠蛱蝶线粒体基因组全序列测定和分析

【目的】了解闪蛱蝶亚科属间及种间的分子系统进化关系。【方法】采用PCR步移法对武铠蛱蝶 Chitoria ulupi 线粒体基因组全序列进行了测定和分析。基于线粒体基因组13个蛋白质编码基因的核苷酸序列构建了38种鳞翅目昆虫的系统发育树。【结果】分析结果表明,武铠蛱蝶线粒体基因组全长15 279 bp,包括13个蛋白质编码基因、22个tRNA基因、2个rRNA基因和一段长度为391 bp的A+T富含区,基因排列顺序与其他已知近缘种昆虫相同。武铠蛱蝶线粒体基因组中存在很高的A+T含量（79.9％）。13个蛋白质编码基因中,COII以TTG作为起始密码子,COI以CGA作为起始密码子外,其余均为昆虫典型的起始密码子ATN。COII和ND4基因使用了不完全终止密码子T,其余基因均以典型的TAA为终止密码子。在所测得的22个tRNA基因中,除tRNA^Ser(AGN)缺少DHU臂外,其余tRNA均能形成典型的三叶草结构。与其他多数鳞翅目昆虫一样,武铠蛱蝶的A+T富含区中有一段由ATAGAA引导的保守的多聚T结构,长度为21 bp,并散布着一些长短不一的串联重复单元。系统发育树结果显示,总科级别的系统发育关系为：卷蛾总科＋（凤蝶总科＋（螟蛾总科＋(夜蛾总科＋蚕蛾总科＋尺蛾总科)））;在蛱蝶科物种中,武铠蛱蝶与猫蛱蝶Timelaea maculate 亲缘关系最近。【结论】基于分子标记构建的鳞翅目昆虫系统发育关系与传统的形态学分类结果基本一致。     

The complete mitogenome of Bombyx mori strain Dazao (Lepidoptera: Bombycidae) and comparison with other lepidopteran insects

The complete mitochondrial genome (mitogenome) of Bombyx mori strain Dazao (Lepidoptera: Bombycidae) was determined to be 15,653 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a A + T-rich region. It has the typical gene organization and order of mitogenomes from lepidopteran insects. The AT skew of this mitogenome was slightly positive and the nucleotide composition was also biased toward A + T nucleotides (81.31%). All PCGs were initiated by ATN codons, except for cytochrome c oxidase subunit 1 (cox1) gene which was initiated by CGA. The cox1 and cox2 genes had incomplete stop codons consisting of just a T. All the tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A + T-rich region of the mitogenome was 495 bp in length and consisted of several features common to the lepidopteras. Phylogenetic analysis showed that the B. mori Dazao was close to Bombycidae.     

The complete mitogenome of the Chinese bush cricket, Gampsocleis gratiosa （Orthoptera： Tettigonioidea）

The complete mitochondrial genome (mitogenome) of Gampsocleis gratiosa was determined. The 15, 929 bp in the size of G. gratiosa mitogenome contains a typical gene content, base composition, and codon usage found in metazoan. All 13 protein coding genes (PCGs) of the G. gratiosa mitogenome start with a typical ATN codon. The usual termination codons (TAA and TAG) were found from 10 PCGs. However, the atp6, nad4, and nad5 had incomplete termination codon (T). The anticodons of all tRNAs are identical to those observed in Drosophila yakuba and Locusta migratoria, and can be folded in the form of a typical clover leaf structure except for trnS (AGN). The secondary structure of trnS (AGN) was drawn according with the Steinberg-Cedergren tertiary structure. The A T content (67.4%) of the A T-rich region is relatively lower among the mitogenome regions, in contrast, it usually contains the highest A T content for most insects. Two isolated sequence repeat regions (202 bp) were found in the A T-rich region with mapping and secondary structure information.