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.     

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.     

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 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 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.     

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.     

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.     

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.     

The complete mitogenome of Apocheima cinerarius (Lepidoptera: Geometridae: Ennominae) and comparison with that of other lepidopteran insects

The complete mitochondrial genome (mitogenome) of a female flightless geometrid moth Apocheima cinerarius was found to be 15,722 bp in length, containing 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a control region. The A + T content of the complete mitogenome is 80.83%. The AT skew value ([A − T] / [A + T]) is 0.027. The 13 PCGs of the mitogenome start with typical ATN codons, except for cox1 with the start codon CGA. All the tRNA genes have typical cloverleaf secondary structures, except for trnSer(AGN). The secondary structures of rrnL and rrnS were predicted. Six structural domains including conserved regions (IV, V) and variable regions (I, II, III, VI) were identified in the secondary structure of rrnL. The secondary structure of rrnS consists of 3 structural domains. The control region of A. cinerarius begins with conserved motifs of “ATAGA” + 19-bp poly T. It also contains a microsatellite-like (TA)₂₆, a stem-and-loop structure, and a poly-A stretch. Phylogenetic analysis showed that Geometroidea is more closely related to Bombycoidea than to Noctuoidea. A. cinerarius is more closely related to Biston panterinaria than to Phthonandria atrilineata, which is in accordance with the conventional morphology-based classification.     

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 the Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae)

We determined the complete nucleotide sequence of the mitogenome from Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae). The 15,566 bp circular genome contains atypical gene organization and order for lepidopteran mitogenomes. The mitogenome contains the lowest A+T content (80.16%) among the known lepidopteran mitogenome sequences. An unusual feature is the occurrence of more Ts than As, with a slightly negative AT skewness (−0.021), in the composition of the major genome strand. All protein-coding genes are initiated by ATN codons, except for cytochrome oxidase subunit I, which is proposed by the TTAG sequence as observed in other lepidopterans. All transfer RNAs (tRNAs) have a typical clover-leaf structure of mitochondrial tRNA, except for tRNA ^Ser (AGN) , the DHU arm of which could not form a stable stem-loop structure. Two aligned sequence blocks with a length of more than 50 bp and 90% of the sequence identity were identified in the A+T-rich region of the Saturniidae and Bombycoidae species.     

The complete mitochondrial genome of Eriocheir japonica sinensis (Decapoda: Varunidae) and its phylogenetic analysis

The complete mitochondrial genome (mitogenome) can provide novel insights into understanding the mechanisms underlying mitogenome evolution. In this study, the complete mitogenome of Eriocheir japonica sinensis (Decapoda: Varunidae) was determined to be 16,378 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a D-loop region. The AT skew of the E. j. sinensis mitogenome was slightly negative (−0.016), indicating a higher number of T compared with A nucleotides. The nucleotide composition of the mitogenome was also biased toward A + T nucleotides (71.6%). All PCGs were initiated by ATN codons. Eight of the 13 PCGs harbored the incomplete termination codon by T, or TA. All other tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The D-loop region of the E. j. sinensis mitogenome was 918 bp in length. Based on 13 PCGs, phylogenetic analysis confirmed the placement of E. j. sinensis within the Varunidae.     

Complete nucleotide sequence and organization of the mitogenome of the silk moth Caligula boisduvalii (Lepidoptera: Saturniidae) and comparison with other lepidopteran insects

The 15,360-bp long complete mitogenome of Caligula boisduvalii possesses a gene arrangement and content identical to other completely sequenced lepidopteran mitogenomes, but different from the common arrangement found in most insect order, as the result of the movement of tRNA(Met) to a position 5'-upstream of tRNA Ile. The 330-bp A+T-rich region is apparently capable of forming a stem-and-loop structure, which harbors the conserved flanking sequences at both ends. Dissimilar to what has been seen in other sequenced lepidopteran insects, the initiation codon for C. boisduvalii COI appears to be TTG, which is a rare, but apparently possible initiation codon. The ATP8, ATP6, ND4L, and ND6 genes, which neighbor another PCG at their 3' end, all harbored potential sequences for the formation of a hairpin structure. This is suggestive of the importance of such structures for the precise cleavage of the mRNA of mature PCGs. Phylogenetic analyses of available sequenced species of Bombycoidea, Pyraloidea, and Tortricidea supported the morphology-based current hypothesis that Bombycoidea and Pyraloidea are monophyletic (Obtectomera). As previously suggested, Bombycidae (Bombyx mori and B. mandarina) and Saturniidae (Antheraea pernyi and C. boisduvalii) formed a reciprocal monophyletic group.     

The complete mitochondrial genome of the Ailanthus silkmoth, Samia cynthia cynthia (Lepidoptera: Saturniidae)

The complete mitochondrial genome (mitogenome) of the Ailanthus silkmoth, Samia cynthia cynthia (Lepidoptera: Saturniidae) was determined. The circular genome is 15,345 bp long, and presents a typical gene organization and order for sequenced mitogenomes of Bombycidea species. The nucleotide composition of the genome is highly A+T biased, accounting for 79.86%. The AT skew of the genome is slightly negative, indicating the occurrence of more Ts than As, as found in other Saturniidae species. All protein-coding genes (PCGs) are initiated by ATN codons, except for COI and COII, which are tentatively designated by CGA and GTG, respectively, as observed in other insects. Four of 13 PCGs, including COI, COII, ATP6, and ND3, harbor the incomplete termination codons, T or TA. With an exception for tRNA^Ser(AGN), all other tRNAs can form a typical clover-leaf structure of mitochondrial tRNA. The 359 bp A+T-rich region of S. c. cynthia contains non-repetitive sequences, but harbors several features common to the Bombycidea insects, including the motif ATAGA followed by a poly-T stretch of 19 bp, a microsatellite-like (AT)₇ element preceded by the ATTTA motif, and a poly-A element upstream tRNA^Met. The phylogenetic analyses support the morphology-based current hypothesis that Bombycidae and Saturniidae are monophyletic. Our result confirms that Saturniini and Attacini form a reciprocal monophyletic group within Saturniidae.     

Complete mitochondrial genome of Bactrocera ritsemai (Insecta: Tephritidae) and phylogenetic relationship with its congeners and related tephritid taxa

Bactrocera ritsemai is a dacine fruit fly found in Indonesia. We report here the complete mitogenome of this fruit fly from Lombok, Indonesia determined by Illumina MiSeq sequencing and its phylogenetic relationship with its congeners and related tephritid taxa. The whole mitogenome of B. ritsemai had a total length of 15,927 bp, comprising 37 genes – 13 protein-coding genes (PCGs), 2 ribosomal ribonucleic acid (rRNA) and 22 transfer ribonucleic acid (tRNA) genes – and a control region (D-loop). Of the PCGs, 6 (atp6, cob, cox2, cox3, nad4, nad4l) had ATG start codon, 4 (nad2, nad3, nad5, nad6) had ATT, and one each had ATA (nad1), GTG (atp8) and TCG (cox1). Seven PCGs (atp6, atp8, cox2, cox3, nad2, nad4l, nad6) had TAA stop codon, 3 (cob, nad3, nad4) had TAG, and 3 had incomplete stop codon (cox1 – TA; nad1, nad5 – T). The TΨC-loop of tRNA was absent in trnF while trnS1 lacked the DHU-loop. Phylogenetic analysis based on 15 mt-genes (13 PCGs + 2 rRNA genes) indicated B. ritsemai forming a sister group with B. umbrosa and the subgenus Bactrocera was monophyletic. The genera Bactrocera and Zeugodacus were monophyletic while the subfamilies Dacinae and Tephritinae 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 sequence of the Japanese oak silkmoth, <Emphasis Type="Italic">Antheraea yamamai</Emphasis> (Lepidoptera: Saturniidae)

The 15,338-bp long complete mitochondrial genome (mitogenome) of the Japanese oak silkmoth, Antheraea yamamai (Lepidoptera: Saturniidae) was determined. This genome has a gene arrangement identical to those of all other sequenced lepidopteran insects, but differs from the most common type, as the result of the movement of tRNA^Met to a position 5′-upstream of tRNA^Ile. No typical start codon of the A. yamamai COI gene is available. Instead, a tetranucleotide, TTAG, which is found at the beginning context of all sequenced lepidopteran insects was tentatively designated as the start codon for A. yamamai COI gene. Three of the 13 protein-coding genes (PCGs) harbor the incomplete termination codon, T or TA. All tRNAs formed stable stem-and-loop structures, with the exception of tRNA^Ser(AGN), the DHU arm of which formed a simple loop as has been observed in many other metazoan mt tRNA^Ser(AGN). The 334-bp long A + T-rich region is noteworthy in that it harbors tRNA-like structures, as has also been seen in the A + T-rich regions of other insect mitogenomes. Phylogenetic analyses of the available species of Bombycoidea, Pyraloidea, and Tortricidea bolstered the current morphology-based hypothesis that Bombycoidea and Pyraloidea are monophyletic (Obtectomera). As has been previously suggested, Bombycidae (Bombyx mori and B. mandarina) and Saturniidae (A. yamamai and Caligula boisduvalii) formed a reciprocal monophyletic group.     

The first mitochondrial genome for Brahmin moths (Brahmaeidae) and implications for the higher phylogeny of Bombycoidea

Bombycoidea comprises 10 families and 4723 species, and the phylogenetic relationships among families are still in debate. In this study, we have determined the complete mitochondrial genome (mitogenome) of Brahmaea porphyria. The 15,429-bp mitogenome contains a common set of 37 mitochondrial genes including 13 protein-coding genes, 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and an inferred control region, and shares the conserved gene rearrangement (trnM-trnI-trnQ) in most ditrysian mitogenomes. Moreover, we analysed the secondary structure for all the tRNA genes of B. porphyria and the preference of codon usage in the PCGs of B. porphyria. The putative 373-bp control region (CR) possesses three types of conserved elements, including ATAGA, Ploy-T stretch, and microsatellite-like elements. A phylogenetic analysis among available Bombycoidea mitogenomes using the concatenated 37 mitochondrial genes appears to support the hypothesis of (Sphingidae+Bombycidae)+Saturniidae and the relatively basal phylogenetic position of Brahmaeidae within Bombycoidea.     

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.     

Complete mitochondrial genome of the atlas moth, Attacus atlas (Lepidoptera: Saturniidae) and the phylogenetic relationship of Saturniidae species

Mitochondrial genome (mitogenome) can provide information for genomic structure as well as for phylogenetic analysis and evolutionary biology. In this study, we present the complete mitogenome of the atlas moth, Attacus atlas (Lepidoptera: Saturniidae), a well-known silk-producing and ornamental insect with the largest wing surface area of all moths. The mitogenome of A. atlas is a circular molecule of 15,282 bp long, and its nucleotide composition shows heavily biased towards As and Ts, accounting for 79.30%. This genome comprises 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and an A + T-rich region. It is of note that this genome exhibits a slightly positive AT skew, which is different from the other known Saturniidae species. All PCGs are initiated by ATN codons, except for COI with CGA instead. Only six PCGs use a common stop codon of TAA or TAG, whereas the remaining seven use an incomplete termination codon T or TA. All tRNAs have the typical clover-leaf structure, with an exception for tRNA^Ser(AGN). The A. atlas A + T-rich region contains non-repetitive sequences, but harbors several features common to the Bombycoidea insects. The phylogenetic relationships based on Maximum Likelihood method provide a well-supported outline of Saturniidae, which is in accordance with the traditional morphological classification and recent molecular works.