Analysis of sequences from the extremely A + T-rich genome of Plasmodium falciparum

The genome of the human malaria parasite Plasmodium falciparum has an A + T content of about 82%, higher than any other organism whose DNA has been characterized. Computer analysis of 36 kb of available nucleotide sequences from this species showed that the coding regions, with an A + T content of 69.0%, are flanked by more A + T-rich regions of 86.0% A + T. Within the coding sequences, the A/T ratio was 1.68 in the mRNA sense strand, and overall A + T content in the three codon positions increased in the order 1st-2nd-3rd position. Codons with T or especially A in the third position were strongly preferred. Codon usage among individual parasite genes was very similar compared to genes from other species. Dinucleotide frequencies for the parasite DNA were close to those expected for a random sequence with the known base composition, except that the CpG frequency in the coding sequences was low.     

The complete mitochondrial DNA sequence of the basal hexapod Tetrodontophora bielanensis: evidence for heteroplasmy and tRNA translocations.

We present the complete 15,455-nt mitochondrial DNA sequence of the springtail Tetrodontophora bielanensis (Arthropoda, Hexapoda, Collembola). The gene content is typical of most metazoans, with 13 protein-coding genes (PCGs), 2 genes encoding for ribosomal RNA subunits, and 22 tRNA genes. The nucleotide sequence shows the well-known A+T bias typical of insect mtDNA; its A+T content is lower (72.7%) than that observed in other insect species, but still higher than that in other arthropodan taxa. The bias appears to be uniform across the whole molecule, unlike other insect taxa, which show increased A+T content in the so-called A+T-rich region. However, the bias is slightly higher in the third codon positions of the PCGs (81.4%). Anomalous initiation codons have been observed in the nad2 and the cox1 genes. In the latter, the ATTTAA hexanucleotide is suggested to be involved in the initiation signaling. All tRNAs could be folded into the typical cloverleaf secondary structure, but the tRNA for cysteine appears to be missing the DHU arm. Long tandemly repeated regions (193 nt) were found in the A+T-rich region, which in turn was shown to have the possibility of forming a complex array of secondary structures. One of these structures encompassed the junction between the repeats. The A+T-rich region was also interesting in that it showed heteroplasmy in the number of repeats. Three haplotypes were found, possessing 2, 3, and 4 identical repeats, respectively. The order of protein coding and rRNA genes in the molecule was determined and was identical to that of all insects studied so far. However, two tRNA translocations were found which were unprecedented among Arthropoda. These involved the trnQ, which was found between the rrnS and the A+T-rich region, and the trnS(ucn), which was located between trnM and trnI. A preliminary phylogenetic analysis based on the amino acid sequence of the PCGs failed to find support for the monophyly of Hexapoda.     

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.     

Evolutionary and structural analysis of the cytochrome c oxidase subunit I (COI) gene from Haematobia irritans, Stomoxys calcitrans and Musca domestica (Diptera: Muscidae) mitochondrial DNA.

This work describes the molecular characterization of the cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA from three species of great medical and veterinary importance: the horn fly, Haematobia irritans, the stable fly, Stomoxys calcitrans and the house fly, Musca domestica (Diptera: Muscidae) (Linnaeus). The nucleotide sequence in all species was 1536 bp in size and coded for a 512 amino acid peptide. The nucleotide bias for an A+T-rich sequence is linked to three features: a high A+T content throughout the entire gene, a high A+T content in the third codon position, and a predominance of A+T-rich codons. An anomalous TCG (serine) start codon was identified. Comparative analysis among members of the Muscidae, Scatophagidae, Calliphoridae and Drosophilidae showed high levels of nucleotide sequence conservation. Analysis of the divergent amino acids and COI protein topologies among these three Muscidae species agreed with the evolutionary model suggested for the insect mitochondrial COI protein. The characterization of the structure and evolution of this gene could be informative for further evolutionary analysis of dipteran species.     

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.     

Analysis of Genomic G + C Content, Codon Usage, Initiator Codon Context and Translation Termination Sites In Tetrahymena Thermophila

In recent years, the amount of molecular sequencing data from Tetrahymena thermophila has dramatically increased. We analyzed G + C content, codon usage, initiator codon context and stop codon sites in the extremely A + T rich genome of this ciliate. Average G + C content was 38% for protein coding regions, 21% for 5' non-coding sequences, 19% for 3' non-coding sequences, 15% for introns, 19% for micronuclear limited sequences and 17% for macronuclear retained sequences flanking micronuclear specific regions. The 75 available T. thermophila protein coding sequences favored codons ending in T and, where possible, avoided those with G in the third position. Highly expressed genes were relatively G + C-rich and exhibited an extremely biased pattern of codon usage while developmentally regulated genes were more A + T-rich and showed less codon usage bias. Regions immediately preceding Tetrahymena translation initiator codons were generally A-rich. For the 60 stop codons examined, the frequency of G in the end + 1 site was much higher than expected whereas C never occupied this position.     

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 sequence,organization, and evolution of the Locusta migratoria mitochondrial genome

The sequencing of the cloned Locusta migratoria mitochondrial genome has been completed. The sequence is 15,722 by in length and contains 75.3% A+T, the lowest value in any of the five insect mitochondrial sequences so far determined. The protein coding genes have a similar A+T content (74.1%) but are distinguished by a high cytosine content at the third codon position. The gene content and organization are the same as in Drosophila yakuba except for a rearrangement of the two tRNA genes tRNA^lys and tRNA^asp. The A+T-rich region has a lower A+T nucleotide content than in other insects, and this is largely due to the presence of two G+C-rich 155-bp repetitive sequences at the 5 end of this section and the beginning of the adjacent small rRNA gene. The sizes of the large and small rRNA genes are 1,314 and 827 bp, respectively, and both sequences can be folded to form secondary structures similar to those previously predicted for Drosophila. The tRNA genes have also been modeled and these show a strong resemblance to the dipteran tRNAs, all anticodons apparently being conserved between the two species. A comparison of the protein coding nucleotide sequences of the locust DNA with the homologous sequences of five other arthropods (Drosophila yakuba, Anopheles quadrimaculatus, Anopheles gambiae, Apis mellifera, and Artemia franciscana) was performed. The amino acid composition of the encoded proteins in Locusta is similar to that of Drosophila, with a Dayhoff distance twice that of the distance between the fruit fly and the mosquitoes. A phylogenetic analysis revealed the locust genes to be more similar to those of the Dipterans than to those of the honeybee at both the nucleotide and amino acid levels. A comparative analysis of tRNA orders, using crustacean mtDNAs as outgroups, supported this. This high level of divergence in the Apis genome has been noted elsewhere and is possibly an effect of directional mutation pressure having resulted in an accelerated pattern of sequence evolution. If the general assumption that the Holometabola are monophyletic holds, then these results emphasize the difficulties of reconstructing phylogenies that include lineages with variable substitution rates and base composition biases. The need to exercise caution in using information about tRNA gene orders in phylogenetic analysis is also illustrated. However, if the honeybee sequence is excluded, the correspondence between the other five arthropod sequences supports the findings of previous studies which have endorsed the use of mtDNA sequences for studies of phylogeny at deep levels of taxonomy when mutation rates are equivalent. Correspondence to: P.K. Flook     

Complete mitochondrial genome of Oxya chinensis （Orthoptera, Acridoidea）

The complete sequence of Oxya chinensis （0. chinensis） mitochondrial genome is reported here. It is 15,443 bp in length and contains 75.9% A＋T. The protein-coding genes have a similar A＋T content （75.2%）. The initiation codon of the cytochrome oxidase subunit I gene in the mitochondrial genome of O. chinensis appears to be ATC, instead of the tetranucleotides that have been reported in Locusta migratoria （L migratoria） mitochondrial genome. The sizes of the large and small ribosomal RNA genes are 1319 and 850 bp, respectively. The transfer RNA genes have been modeled and showed strong resemblance to the dipteran transfer RNAs, and all anticodons are identical to those of dipteran. The A＋T-rich region is 562 bp, shorter than that of other known Orthoptera insects. The six conserved domains were identified within the A＋T-rich region by comparing its sequence with those of other grasshoppers. The result of phylogenetic analysis based on the dataset containing 12 concatenated protein sequences confirms the close relation-ship of O. chinensis with L migratoria.     

Cellulase Linkers Are Optimized Based on Domain Type and Function: Insights from Sequence Analysis,Biophysical Measurements,and Molecular Simulation

Cellulase enzymes deconstruct cellulose to glucose, and are often comprised of glycosylated linkers connecting glycoside hydrolases (GHs) to carbohydrate-binding modules (CBMs). Although linker modifications can alter cellulase activity, the functional role of linkers beyond domain connectivity remains unknown. Here we investigate cellulase linkers connecting GH Family 6 or 7 catalytic domains to Family 1 or 2 CBMs, from both bacterial and eukaryotic cellulases to identify conserved characteristics potentially related to function. Sequence analysis suggests that the linker lengths between structured domains are optimized based on the GH domain and CBM type, such that linker length may be important for activity. Longer linkers are observed in eukaryotic GH Family 6 cellulases compared to GH Family 7 cellulases. Bacterial GH Family 6 cellulases are found with structured domains in either N to C terminal order, and similar linker lengths suggest there is no effect of domain order on length. O-glycosylation is uniformly distributed across linkers, suggesting that glycans are required along entire linker lengths for proteolysis protection and, as suggested by simulation, for extension. Sequence comparisons show that proline content for bacterial linkers is more than double that observed in eukaryotic linkers, but with fewer putative O-glycan sites, suggesting alternative methods for extension. Conversely, near linker termini where linkers connect to structured domains, O-glycosylation sites are observed less frequently, whereas glycines are more prevalent, suggesting the need for flexibility to achieve proper domain orientations. Putative N-glycosylation sites are quite rare in cellulase linkers, while an N-P motif, which strongly disfavors the attachment of N-glycans, is commonly observed. These results suggest that linkers exhibit features that are likely tailored for optimal function, despite possessing low sequence identity. This study suggests that cellulase linkers may exhibit function in enzyme action, and highlights the need for additional studies to elucidate cellulase linker functions.     

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 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.     

蜱螨线粒体基因组研究进展

蜱螨亚纲包括蜱类和螨类, 是节肢动物中物种多样性最高的类群之一。本文综述了当前已测序的28种蜱螨线粒体基因组的研究成果。概括起来, 蜱螨线粒体基因组具有以下特点： （1）大小变异显著, 其中柑橘全爪螨Panonychus citri线粒体基因组在目前已测节肢动物中最小（13 077 bp）; （2）一般碱基组成偏向A和T, 但6种蜱螨具有相反的GC-偏斜（正值）; （3）基因组的碱基组成及A+T富集区的位置、 长度和拷贝数等变异显著, 其中4种叶螨的A+T含量最高, 其A+T富集区在目前已测节肢动物中最短（44~57 bp）; （4）基因高度重排, 特别是真螨总目的种类, 但重排与高分类阶元无相关性; （5）真螨总目部分螨类的tRNA基因极度缩短, 不能形成经典的三叶草二级结构。作者建议要进一步测定更多蜱螨的线粒体基因组, 验证蜱螨非典型tRNA基因的生物学功能性, 分析蜱螨线粒体基因组的分子进化机制, 开展蜱螨线粒体转录组研究等。     

The complete mitochondrial genome of grouse locust Tetrix japonica (Insecta: Orthoptera: Tetrigoidea)

We have determined the complete mitochondrial genome of a species of grouse locust, Tetrix japonica. The total length of the T. japonica mitogenome is 15,128 bp with 75.57% A+T content. It consists of 13 protein-coding, 22 transfer RNA (tRNA), and 2 ribosomal RNA (rRNA) genes, and an A+T-rich region. The A+T-rich region was located between the small rRNA and tRNA-Ile genes and is 531 bp in length.     

Thermal and chemical denaturation of the BRCT functional module of human 53BP1

BRCTs are protein-docking modules involved in eukaryotic DNA repair. They are characterized by low sequence homology with generally well-conserved structure organization. In a considerable number of proteins, a pair of BRCT structural repeats occurs, connected with inter-BRCT linkers, variable in length, sequence and structure. Linkers may separate and control the relative position of BRCT domains as well as protect and stabilize the hydrophobic inter-BRCT interface region. Their vital role in protein function has been demonstrated by recent findings associating missense mutations in the inter-repeat linker region of the BRCT domain of BRCA1 (BRCA1-BRCT) to hereditary breast/ovarian cancer. The interaction of 53BP1 with the core domain of the p53 tumor suppressor involves the C-terminal BRCT repeat as well as the inert-BRCT linker of the tandem BRCT domain of 53BP1 (53BP1-BRCT). High-accuracy differential scanning calorimetry (DSC) and circular dichroism (CD) have been employed to characterize the heat-induced unfolding of 53BP1-BRCT domain. The calorimetric results provide evidence for unfolding to an intermediate, only partly unfolded state, which, based on the CD results, retains the secondary structural characteristics of the native protein. A direct comparison with the corresponding thermal processes for BRAC1-BRCT and BARD1-BRCT provides evidence that the observed behavior is analogous to BRCA1-BRCT even though the two domains differ substantially in the linker structure. Moreover, chemical denaturation experiments of the untagged 53BP1-BRCT and comparison with BRCA1 and BARD1 BRCTs show that no clear association can be drawn between the structural organization of the inter-BRCT linkers and the overall stability of the BRCT domains.     

Three domains in the simian virus 40 core origin orchestrate the binding, melting, and DNA helicase activities of T antigen.

The simian virus 40 (SV40) core origin of replication consists of three functional domains. The sequence 5'-CACTACTTCTGGAATAG-3' with an imperfect inverted repeat (underlined), a palindrome with four 5'-GAGGC-3' pentanucleotide repeats, and a 17-base-pair A + T-rich segment. We have been able to assign primary functions to each domain. Remarkably, SV40 large T antigen melted the inverted repeat domain in the complete absence of other origin sequences. Presumably, this protein-DNA interaction initiates a replication bubble that leads to daughter strand DNA synthesis. The pentanucleotide domain alone docked and arranged T antigen at the origin. The A + T-rich domain had no independent function, but, in the presence of the other two domains, allowed bound T antigen to extend the replication bubble. Thus, three domains of the origin coordinate the binding, melting, and DNA helicase activities of T antigen in an ordered sequence of events to initiate DNA replication.     

Negative correlation of G+C content at silent substitution sites between orthologous human and mouse protein-coding sequences.

We conducted a genome-wide analysis of variations in guanine plus cytosine (G+C) content at the third codon position at silent substitution sites of orthologous human and mouse protein-coding nucleotide sequences. Alignments of 3776 human protein-coding DNA sequences with mouse orthologs having >50 synonymous codons were analyzed, and nucleotide substitutions were counted by comparing sequences in the alignments extracted from gap-free regions. The G+C content at silent sites in these pairs of genes showed a strong negative correlation (r = -0.93). Some gene pairs showed significant differences in G+C content at the third codon position at silent substitution sites. For example, human thymine-DNA glycosylase was A+T-rich at the silent substitution sites, while the orthologous mouse sequence was G+C-rich at the corresponding sites. In contrast, human matrix metalloproteinase 23B was G+C-rich at silent substitution sites, while the mouse ortholog was A+T-rich. We discuss possible implications of this significant negative correlation of G+C content at silent sites.     

Evolution of the A+T-rich region of mitochondrial DNA in the melanogaster species subgroup of Drosophila

We determined the nucleotide sequences of two regions in the A+T-rich region of mitochondrial DNA (mtDNA) in the siI and siII types of D. simulans, the maII type of D. mauritiana, and D. sechellia. The sequences were aligned with those of the corresponding regions of siIII of D. simulans and maI of D. mauritiana, D. melanogaster, and D. yakuba. The type I and type II elements and the T-stretches were detected in all eight of the mtDNA types compared, indicating that the three elements are essential in the A+T-rich region of this species subgroup. The alignment revealed several short repetitive sequences and relatively large deletions in the central portions of the region. In the highly conserved sequence elements in the type II elements, the substitution rates were not uniform among lineages and acceleration in the substitution rate might have been due to loss of functional constraint in the stem–loop-forming sequences predicted in the type II elements. Patterns of nucleotide substitutions observed in the A+T-rich region were further compared with those in the coding regions and in the intergenic regions of mtDNA. Substitutions between A and T were particularly repressed in the highly conserved sequence elements and in the intergenic regions compared with those in the A+T-rich region excluding the highly conserved sequence elements and in the fourfold degenerate sites in the coding regions. The functional and structural characteristics of the A+T-rich region that might be involved in this substitutional bias are discussed.     

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.