The complete mitochondrial genome of Tuta absoluta (Lepidoptera: Gelechiidae) and genetic variation in two newly invaded populations in China

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating invasive pest worldwide, causing severe damage to tomatoes. Recently, it has been recorded in the northwestern and southwestern parts of China. Here, the mitogenomes and genetic variation of two newly invaded T. absoluta populations in Xinjiang and Yunnan, were determined. The results showed that the complete mitogenome size of T. absoluta is 15298 bp for the individual from Xinjiang and 15296 bp for the individual from Yunnan, which were both longer than the reported mitogenome from Spain (15290 bp). The mitogenome sequences of individuals collected from three locations showed high levels of sequence similarity, except for 8 polymorphic sites, which were in genes cox2 (1 site), cox3 (2 sites), cob (1 site), atp6 (1 site), nad1 (2 sites) and nad5 (1 site). Tuta absoluta mitogenomes share many features with other 6 Gelechiidae mitogenomes, except for several differences in the start and stop codons of protein-coding genes and the length of intergenic spacers. Seven partial mitochondrial genes (cox1, cox2, cox3, atp6, cob, nad1, and nad5) were used for genetic variation analysis, and significant population differentiation was found between the two populations based on cox2, atp6, nad1, and nad5. The complete mitogenomes and sensitive mitochondrial gene markers reported here provide useful data for further population genetics study of this pest.     

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 rearranged mitochondrial genome of Podagrion sp. (Hymenoptera: Torymidae), a parasitoid wasp of mantis

The complete sequence of the mitochondrial genome of Podagrion sp. (Hymenoptera: Torymidae) is described. The mitogenome was 15,845 bp in size, and contained typical sets of mitochondrial genes. The base composition of the Podagrion sp. mitogenome was also biased toward A + T bases (81.8%). The mitochondrial genome of Podagrion sp. has a weak AT skew (0.07) and a strong GC skew (?0.26). Podagrion sp. exhibits a novel rearrangement compared with the ancestral order, including six protein-coding genes (nad3, cox3, atp6, atp8, cox2 and cox1), which have inverted to the minor strand from the major strand. The A + T-rich region of Podagrion sp., which is located between trnN and trnI, have five tandem repeats. The apomorphic rearrangements, including the conserved block “cox3-atp6-atp8-cox2-cox1-nad5-nad4-nad4l-nad6-cob” and the special locations of trnV and trnA, were mapped onto the phylogeny of Proctotrupomorpha.     

Characterization of the complete mitochondrial genome of Tryporyza incertulas, in comparison with seven other Pyraloidea moths

The complete 15,223-bp mitochondrial genome (mitogenome) of Tryporyza incertulas (Walker) (Lepidoptera: Pyraloidea: Crambidae) was determined, characterized and compared with seven other species of superfamily Pyraloidea. The order of 37 genes was typical of insect mitochondrial DNA sequences described to date. Compared with other moths of Pyraloidea, the A + T biased (77.0%) of T. incertulas was the lowest. Eleven protein-coding genes (PCGs) utilized the standard ATN, but cox1 used CGA and nad4 used AAT as the initiation codons. Ten protein-coding genes had the common stop codon TAA, except nad3 having TAG as the stop codon, and cox2, nad4 using T, TA as the incomplete stop codons, respectively. All of the tRNA genes had typical cloverleaf secondary structures except trnS1(AGN), in which the dihydrouridine (DHU) arm did not form a stable stem-loop structure. There was a spacer between trnQ and nad2, which was common in Lepidoptera moths. A 6-bp motif ‘ATACTA’ between trnS2(UCN) and nad1, a 7-bp motif “AGC(T)CTTA” between trnW and trnC and a 6-bp motif “ATGATA” of overlapping region between atp8 and atp6 were found in Pyraloidea moths. The A + T-rich region contained an ‘ATAGT(A)’-like motif followed by a poly-T stretch. In addition, two potential stem-loop structures, a duplicated 19-bp repeat element, and two microsatellites ‘(TA)₁₂’ and ‘(TA)₉’ were observed in the A + T-rich region of T. incertulas mitogenome. Finally, the phylogenetic relationships of Pyraloidea species were constructed based on amino acid sequences of 13 PCGs of mitogenomes using Bayesian inference (BI) and maximum likelihood (ML) methods. These molecular-based phylogenies supported the morphological classification on relationships within Pyraloidea species.     

Characterization of the complete mitochondrial genome of Cryptotermes domesticus (Blattodea: Kalotermitidae): Genome description and phylogenetic implications

The complete mitochondrial genome of Cryptotermes domesticus (Haviland) was sequenced and annotated to study its characteristics and the phylogenetic relationship of C. domesticus to other termite species. The mitogenome of C. domesticus is a circular, close, and double-stranded molecule with a length of 15,655 bp. The sequenced mitogenome contains 37 typical genes, which are highly conserved in gene size, organization, and codon usage. Transfer RNA genes (tRNAs) also have typical secondary structures. All of the 13 protein-coding genes (PCGs) start with an ATN codon, except for nad4, which starts with GTG and terminates with the terminal codon TAA and TAG or the incomplete form T-- (cox2 and nad5). Most tRNAs have a typical cloverleaf structure, except for trnS1, in which this form is replaced by a simple loop and lacks the dihydrouridine (DHU) arm. The nucleotide diversity (Pi) and nonsynonymous (Ka)/synonymous (Ks) mutation rate ratios indicate that nad1, cox1, and cox3 are the most conserved genes, and that cox1 has the lowest rate of evolution. In addition, an 89 bp repeated sequence was found in the A + T-rich region. Phylogenetic analysis was performed using Bayesian inference (BI) and maximum likelihood (ML) methods based on 13 PCGs, and the monophyly of Kalotermitidae was supported.     

Mitogenome evolution in ladybirds: Potential association with dietary adaptation

Dietary shifts can alter the relative availability of different nutrients and are therefore associated with metabolic adaptation in animals. The Coccinellidae (ladybirds) exhibits three major types of feeding habits and provides a useful model to study the effects of dietary changes on the evolution of mitogenomes, which encode proteins directly involved in energy metabolism. Here, mitogenomes of three coccinellid species were newly sequenced. These data were combined with other ten previously sequenced coccinellid mitogenomes to explore the relationship between mitogenome evolution and diets. Our results indicate that mitogenomic data can be effectively used to resolve phylogenetic relationships of Coccinellidae. Strong codon usage bias in coccinellid mitogenomes was predominantly determined by nucleotide composition. The 13 mitochondrial protein‐coding genes (PCGs) globally evolved under negative constraints, with some PCGs showing a stronger purifying selection. Six PCGs (nad3, nad4L, and nad5 from Complex I; cox1 and cox3 from Complex IV; and atp6 from Complex V) displayed signs of positive selection. Of these, adaptive changes in cox3 were potentially associated with metabolic differences resulting from dietary shifts in Coccinellidae. Our results provide insights into the adaptive evolution of coccinellid mitogenomes in response to both dietary shifts and other life history traits.     

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 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.     

Complete mitochondrial exploration of Echinococcus multilocularis from French alveolar echinococcosis patients

Alveolar echinococcosis (AE) is a parasitosis that is expanding worldwide, including in Europe. The development of genotypic markers is essential to follow its spatiotemporal evolution. Sequencing of the commonly used mitochondrial genes cob, cox1, and nad2 shows low discriminatory power, and analysis of the microsatellite marker EmsB does not allow nucleotide sequence analysis. We aimed to develop a new method for the genotyping of Echinococcus multilocularis based on whole mitochondrial genome (mitogenome) sequencing, to determine the genetic diversity among 30 human visceral samples from French patients, and compare this method with those currently in use. Sequencing of the whole mitochondrial genome was carried out after amplification by PCR, using one uniplex and two multiplex reactions to cover the 13,738 bp of the mitogenome, combined with Illumina technology. Thirty complete mitogenome sequences were obtained from AE lesions. One showed strong identity with Asian genotypes (99.98% identity) in a patient who had travelled to China. The other 29 mitogenomes could be differentiated into 13 haplotypes, showing higher haplotype and nucleotide diversity than when using the cob, cox1, and nad2 gene sequences alone. The mitochondrial genotyping data and EmsB profiles did not overlap, probably because one method uses the mitochondrial genome and the other the nuclear genome. The pairwise fixation index (F_st) value between individuals living inside and those living outside the endemic area was high (F_st = 0.222, P = 0.002). This is consistent with the hypothesis of an expansion from historical endemic areas to peripheral regions.     

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.     

Comparative analysis of mitochondrial genomes of Nirvanini and Evacanthini (Hemiptera: Cicadellidae) reveals an explicit evolutionary relationship

Mitogenomes of five leafhopper species, Chudania hellerina and Concaveplana rufolineata in Nirvanini, Carinata rufipenna, Evacanthus danmainus and E. heimianus representing Evacanthini, were sequenced. The lengths of these five mitogenomes range from 15,044 (C. hellerina) to 15,680 bp (E. heimianus). All five mitogenomes exhibit similar base composition, gene size and codon usage of protein-coding genes. All 22 tRNA genes have typical cloverleaf secondary structures, except for trnS1 (AGN) which appears to lack the dihydrouridine arm. The two included Nirvanini species employ the anticodon TCT instead of the commonly used GCT in trnS1 (AGN). Genes nad2, atp8 and nad6 were highly variable while cox1 and cob showed the lowest nucleotide diversity. Phylogenetic analyses of two concatenated nucleotide datasets, incorporating the newly sequenced taxa and other available membracoid mitogenomes, recovered each included leafhopper subfamily as monophyletic with evacanthine tribes Nirvanini and Evacanthini forming monophyletic sister clades. A relationship among Evacanthinae, Cicadellinae and Typhlocybinae received moderate branch support.     

Characterisation of the complete mitochondrial genome of Helice wuana (Grapsoidea: Varunidae) and comparison with other Brachyuran crabs

The mitochondrial genome (mitogenome) provides important information for phylogenetic analysis and understanding evolutionary origins. Herein, we sequenced, annotated, and characterised the mitogenome of the crab Helice wuana to better understand its molecular evolution and phylogeny. The 16,359 bp mitogenome includes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region. The genome composition is highly A + T biased 68.42%, and exhibits a negative AT–skew (? 0.036) and GC–skew (? 0.269) among Brachyura crabs. Gene rearrangements were detected, as was tandem duplication followed by random loss, which explains the translocation of mitochondrial genes. Phylogenetic analysis showed that H. wuana and H. tientsinensis clustered on one branch with high nodal support values. These results confirm that the placement of H. wuana within the Varunidae family of Thoracotrematan crabs. This study will provided a better understanding for gene rearrangements and crab evolution in the further.     

Characterization and Phylogenetic Analysis of the Mitochondrial Genome of Shiraia bambusicola Reveals Special Features in the Order of Pleosporales

Shiraia bambusicola P. Henn. is a pathogenic fungus of bamboo, and its fruiting bodies are regarded as folk medicine. We determined and analyzed its complete mitochondrial DNA sequence (circular DNA molecule of 39,030 bp, G + C content of 25.19%). It contains the typical genes encoding proteins involved in electron transport and coupled oxidative phosphorylation (nad1-6 and nad4L, cob and cox1-3), one ATP synthase subunit (atp6), 4 hypothetical proteins, and two genes for large and small rRNAs (rnl and rns). There is a set of 32 tRNA genes comprising all 20 amino acids, and these genes are evenly distributed on the two strands. Phylogenetic analyses based on concatenated mitochondrial proteins indicated that S. bambusicola clustered with members of the order Pleosporales, which is in agreement with previous results. The gene arrangements of Dothideomycetes species contained three regions of gene orders partitioned in their mitochondrial genomes, including block 1 (nad6-atp6), block 2 (nad1-cox3) and block 3 (genes around rns). S. bambusicola displayed unique special features that differed from the other Pleosporales species, especially in the coding regions around rns (trnR-trnY). Moreover, a comparison of gene orders in mitochondrial genomes from Pezizomycotina revealed that although all encoded regions are located on the same strand in most Pezizomycotina mtDNAs, genes from Dothideomycetes species had different orientations, as well as diverse positions and colocalization of genes (such as cox3, cox1-cox2 and nad2–nad3); these distinctions were regarded as class-specific features. Interestingly, two incomplete copies of the atp6 gene were found on different strands of the mitogenomic DNA, a finding that has not been observed in the other analyzed fungal species. In our study, mitochondrial genomes from Dothideomycetes species were comprehensively analyzed for the first time, including many species that have not appeared in previous reports.     

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.     

Characterization of the complete mitochondrial genome of the giant silkworm moth, Eriogyna pyretorum (Lepidoptera: Saturniidae)

The complete mitochondrial genome (mitogenome) of Eriogyna pyretorum (Lepidoptera: Saturniidae) was determined as being composed of 15,327 base pairs (bp), including 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The arrangement of the PCGs is the same as that found in the other sequenced lepidopteran. The AT skewness for the E. pyretorum mitogenome is slightly negative (-0.031), indicating the occurrence of more Ts than As. The nucleotide composition of the E. pyretorum mitogenome is also biased toward A + T nucleotides (80.82%). All PCGs are initiated by ATN codons, except for cytochrome c oxidase subunit 1 and 2 (cox1 and cox2). Two of the 13 PCGs harbor the incomplete termination codon by T. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA, with the exception of trnS1(AGN) and trnS2(UCN). Phylogenetic analysis among the available lepidopteran species supports the current morphology-based hypothesis that Bombycoidea, Geometroidea, Notodontidea, Papilionoidea and Pyraloidea are monophyletic. As has been previously suggested, Bombycidae (Bombyx mori and Bombyx mandarina), Sphingoidae (Manduca sexta) and Saturniidae (Antheraea pernyi, Antheraea yamamai, E. pyretorum and Caligula boisduvalii) formed a group.     

Mitochondrial genome characteristics of Somena scintillans (Lepidoptera: Erebidae) and comparation with other Noctuoidea insects

In this study, mitogenome of Somena scintillans (Lepidoptera: Erebidae) were sequenced and compared with other Noctuoidea species. The mitogenome is 15,410 base pairs in length. All 13 protein-coding genes (PCGs) are initiated by ATN codons except cox1 with CGA and all of PCGs terminate with TAA except nad4 with TAG. The codons ACG and CGC are absent. All the tRNA genes could be folded into the typical cloverleaf secondary structure except the trnS1 which not only loses dihydrouridine (DHU) arm but also mutates its anticodon into TCT. In the AT-rich region of the mitogenome the motif ‘ATAGA’ mutates to ‘ATATA’ and two copies of 161 bp-tandem repeats and two ‘TA’ short tandem repeats are founded. Phylogenetic analyses showed that S. scintillans is clustered into subfamily Lymatriinae. The phylogenetic relationships within Noctuoidea is (((Nolidae + (Euteliidae + Noctuidae)) + Erebidae) + Notodontidae)     

The complete mitochondrial genome of Mahanta tanyae compared with other zygaenoid moths (Lepidoptera: Zygaenoidea)

The complete mitochondrial genome (mitogenome) of Mahanta tanyae was sequenced and extensively compared with all seven additionally reported zygaenoid mitogenomes. The M. tanyae mitogenome is circular, double-stranded, and 15,323 bp long. Gene content, gene order, and orientation are all typical of Lepidoptera, despite the existence of gene rearrangements for some other zygaenoid mitogenomes. Comparative analyses further showed that the incomplete termination codon T is consistently recognized in the mitochondrial cox1, cox2 and nad4 genes of all zygaenoid species, as well as in the nad5 gene in two limacodid species. Among 13 protein-coding genes, nad6 exhibits the highest evolutionary rate. The structure for each tRNA is highly conserved, including loss of the dihydorouidine (DHU) arm in trnS1 (AGN), but remarkable nucleotide variation exists, primarily in the pseudouridine (TψC) loops. Interestingly, in four species of Zygaenidae, the anticodons for trnS1 (AGN) are consistently UCU, instead of the routinely used codon GCU, in all three species of Limacodidae. In the intergenic region between trnS2 and nad1, a short sequence before the motif “ATACTAA” is present in the M. tanyae mitogenome that is unique among reported zygaenoid mitogenomes. In the A + T-rich region between the motif “ATTTA” and the microsatellite (AT)_n element, some nucleotides were present for most zygaenoid mitogenomes, which is, to our knowledge, rare even in reported lepidopteran mitogenomes. Phylogenetic analyses based on the combined 37 mitochondrial genes confirmed the position of M. tanyae in Limacodidae of the Zygaenoidea.     

Complete nucleotide sequence and organization of the mitochondrial genome of eri-silkworm,Samia cynthia ricini (Lepidoptera: Saturniidae)

Samia cynthia ricini is a commercial silk-producing insect that is now reared year-round in Korea, with the expectation of being utilized for diverse purposes. In this report, we present the complete mitochondrial genome (mitogenome) of S. c. ricini. The 15,384-bp long S. cynthia ricini mitogenome was amplified into 26 short fragments using three long overlapping fragments using primers designed from reported lepidopteran mitogenome sequences. The genome comprises 37 genes (13 protein-coding genes, two rRNA genes, and 22 tRNA genes), and one large non-coding region termed the A + T-rich region. The A/T content of the third codon position was 91.7%, which was 18.8% and 21.6% higher than those of first and second codon positions, respectively. The high A/T content in the genome is reflected in codon usage, accounting for 39.5% of A/T-composed codons (TTA, ATT, TTT, and ATA). Unlike a previous report on the start codon for the COI gene, the S. c. ricini COI gene commences with a typical ATT codon. A total of 221 bp of non-coding sequences are dispersed in 17 regions, ranging in size from 1 to 54 bp, which comprise 1.4% of the total genome. One of the non-coding sequence located between tRNA^Gln and ND2 (54 bp) has 77% sequence homology with the 5′-sequence of the neighboring ND2 gene, suggesting partial duplication of the sequence during evolution. The 361-bp long A + T-rich region contains an 18 bp-long poly-T stretch, ATAGA motif, ATTTA element, microsatellite-like A/T sequence, poly-A stretch and one tRNA-like sequence, as typically found in Lepidoptera including Bombycoidea.     

Characterization of the Complete Mitochondrial Genome of Cerura menciana and Comparison with Other Lepidopteran Insects

The complete mitochondrial genome (mitogenome) of Cerura menciana (Lepidoptera: Notodontidae) was sequenced and analyzed in this study. The mitogenome is a circular molecule of 15,369 bp, containing 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and a A+T-rich region. The positive AT skew (0.031) indicated that more As than Ts were present. All PCGs were initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which was initiated by CAG. Two of the 13 PCGs contained the incomplete termination codon T or TA, while the others were terminated with the stop codon TAA. The A+T-rich region was 372 bp in length and consisted of an ‘ATAGA’ motif followed by an 18 bp poly-T stretch, a microsatellite-like (AT)₈ and a poly-A element upstream of the trnM gene. Results examining codon usage indicated that Asn, Ile, Leu2, Lys, Tyr and Phe were the six most frequently occurring amino acids, while Cys was the rarest. Phylogenetic relationships, analyzed based on the nucleotide sequences of the 13 PCGs from other insect mitogenomes, confirmed that C. menciana belongs to the Notodontidae family.     

The complete nucleotide sequence of the mitochondrial genome of <Emphasis Type="Italic">Phthonandria atrilineata</Emphasis> (Lepidoptera: Geometridae)

Using long-polymerase chain reaction (Long-PCR) method, we determined the complete nucleotide sequence of the mitochondrial genome (mitogenome) of Phthonandria atrilineata. The complete mtDNA from P. atrilineata was 15,499 base pairs in length and contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The P. atrilineata genes were in the same order and orientation as the completely sequenced mitogenomes of other lepidopteran species. The nucleotide composition of P. atrilineata mitogenome was biased toward A + T nucleotides (81.02%), and the 13 PCGs show different A + T contents that range from 73.25% (cox1) to 92.12% (atp8). Phthonandria had the canonical set of 22 tRNA genes, that fold in the typical cloverleaf structure described for metazoan mt tRNAs, with the unique exception of trnS(AGN). The phylogenetic relationships were reconstructed with the concatenated sequences of the 13 PCGs of the mitochondrial genome, which confirmed that P. atrilineata is most closely related to the superfamily Bombycoidea.