The mitochondrial genome of the firefly, Pyrocoelia rufa: complete DNA sequence, genome organization, and phylogenetic analysis with other insects

The complete nucleotide sequences of the mt genome from the firefly, Pyrococelia rufa (Coeleoptera: Lampyridae) was determined. The circular genome is 17,739-bp long, and contains a typical gene complement, order, and arrangement identical to Drosophila yacuba. The presence of 1,724-bp long intergenic spacer in the P. rufa mt genome is unique. The putative initiation codon for ND1 gene appears to be TTG, instead of frequently found ATN. All tRNAs showed stable canonical clover-leaf structure of other mt tRNAs, except for tRNA(Ser) (AGN), DHU arm of which could not form stable stem-loop structure. Phylogenetic analysis among insect orders confirmed a monophyletic Endopterygota, a monophyletic Mecopterida, a monophyletic Diptera, a monophyletic Lepidoptera, and a monophyletic Coleoptera, suggesting that the complete insect mt genome sequence has a resolving power in the diversification events within Endopterygota. However, internal relationships among three coleopteran species are not clear, and the inclusion of some insect orders (i.e., apterygotan T. gertschi) in the analysis provided inconsistent results compared to other molecular studies.     

黄毛纺蚋线粒体基因组全序列测定与分析

利用PCR步移法对黄毛纺蚋的线粒体基因组全序列进行了测定和分析。黄毛纺蚋线粒体基因组全长15904 bp(Gen Bank序列号KP793690),包括13个蛋白编码基因、22个tRNA基因、2个rRNA基因以及长度为939 bp的非编码区。A、T、C、G碱基含量分别为39.1%、35.8%、10.4%、14.7%。9个蛋白编码基因和14个tRNA基因在J链编码,其余4个蛋白编码基因和8个tRNA基因在N链编码,基因排列顺序与其它已知双翅目昆虫相同。13个蛋白编码基因中除COI以TTG作为起始密码外,其余蛋白质基因均以ATN作为起始密码子,终止密码子多数为典型的TAA、TAG,只有COI和ND4L以单独的T作为终止密码子。在所测得的22个tRNA基因中,除tRNASer(AGN)缺少DHU臂外,其余tRNA均能形成典型的三叶草结构。     

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.     

Sequence and phylogenetic analysis of the complete mitochondrial genome of the flour beetle Tribolium castanaeum

We describe the first complete mitochondrial genome sequence from a representative of the insect order Coleoptera, the flour beetle Tribolium castaneum. The 15,881 bp long Tribolium mitochondrial genome encodes 13 putative proteins, two ribosomal RNAs and 22 tRNAs canonical for animal mitochondrial genomes. Their arrangement is identical to that in Drosophila melanogaster, which is considered ancestral for insects and crustaceans (Boore et al., 1998; Hwang, et al., 2001a). Nucleotide composition, amino acid composition, and codon usage fall within the range of values observed in other insect mitochondrial genomes. Most notable features are the use of TCT as tRNA(Ser(AGN)) anticodon instead of GCT, which is used in most other arthropod species, and the relative scarcity of special sequence motifs in the 1431 bp long control region. Phylogenetic analysis confirmed resolving power in the conserved regions of the mitochondrial proteome regarding diversification events, which predate the emergence of pterygote insects, while little resolution was obtained at the level of basal perygote diversification. The partition of faster evolving amino acid sites harbored strong support for joining Lepidoptera with Diptera, which is consistent with a monophyletic Mecopterida.     

The complete nucleotide sequence and gene organization of the mitochondrial genome of the bumblebee, Bombus ignitus (Hymenoptera: Apidae)

The complete 16,434-bp nucleotide sequence of the mitogenome of the bumble bee, Bombus ignitus (Hymenoptera: Apidae), was determined. The genome contains the base composition and codon usage typical of metazoan mitogenomes. An unusual feature of the B. ignitus mitogenome is the presence of five tRNA-like structures: two each of the tRNALeu(UUR)-like and tRNASer(AGN)-like sequences and one tRNAPhe-like sequence. These tRNA-like sequences have proper folding structures and anticodon sequences, but their functionality in their respective amino acid transfers remained uncertain. Among these sequences, the tRNALeu(UUR)-like sequence and the tRNASer(AGN)-like sequence are seemingly located within the A+T-rich region. This tRNASer(AGN)-like sequence is highly unusual in that its sequence homology is very high compared to the tRNAMet of other insects, including Apis mellifera, but it contains the anticodon ACT, which designates it as tRNASer(AGN). All PCG and rRNAs are conserved in positions observed most frequently in insect mitogenome structures, but the positions of the tRNAs are highly variable, presenting a new arrangement for an insect mitogenome. As a whole, the B. ignitus mitogenome contains the highest A+T content (86.9%) found in any of the complete insects mt sequences determined to date. All protein-coding sequences started with a typical ATN codon. Nine of the 13 PCGs have a complete termination codon (all TAA), but the remaining four genes terminate with the incomplete TA or T. All tRNAs have the typical clover-leaf structures of mt tRNAs, except for tRNASer(AGN), in which the DHU arm forms a simple loop. All anticodons of B. ignitus tRNAs are identical to those of A. mellifera. In the A+T-rich region, a highly conserved sequence block that was previously described in Orthoptera and Diptera was also present. The stem-and-loop structures that may play a role in the initiation of mtDNA replication were also found in this region. Phylogenetic analysis among three corbiculate tribes, represented by Melipona bicolor (Meliponini), A. mellifera (Apini), and B. ignitus (Bombini), showed the closest relationship between M. bicolor and B. ignitus.     

Complete mitochondrial genome of Locusta migratoria migratoria (Orthoptera: Oedipodidae): three tRNA-like sequences on the N-strand

The complete 16053 bp mitochondrial genome (mitogenome) sequence of Locusta migratoria migratoria has been determined. This mitogenome contains the base compositional biases and codon usage typical of metazoans, and the RSCU values indicate a negative correlation with the C and G contents in codon. The orientation and gene order of the L. migratoria migratoria is identical to Locusta migratoria migratoiodes. An unusual feature of the L. migratoria migratoria mitogenome is the presence of three tRNA-like structures on the N-strand: one tRNA(Ile)-like and two tRNA(Leu(CUN))-like sequences. The tRNA-like sequences have proper folding structures and anticodons sequences. Two repeated DNA sequences, Rpt I and Rpt II, were found in the A+T-rich region of the L. migratoria migratoria mitogenome. Both repeated sequences have various features. In the 5' region of Rpt I, a 51 bp fragment is localized in the srRNA gene; and there are two tandemly sub-repeated DNA sequences (sub-Rpts), Rpt 1-4, within Rpt I and Rpt II. One stem-loop structure on the N-strand that may be involved in the N-strand replication initiation was found in the A+T-rich region.     

Complete mitochondrial genome of a carabid beetle,Damaster mirabilissimus mirabilissim (Coleoptera: Carabidae)

In the present study, we report the 16 823‐bp long complete mitochondrial genome (mitogenome) of a carabid beetle, Damaster mirabilissimus mirabilissim (Coleoptera: Carabidae), which is endangered in Korea. The gene arrangement of D. m. mirabilissim mitogenome is identical to the most common type found in insects. The start codon of the D. m. mirabilissim COI gene is a typical ATN codon. On the other hand, the initiation codon for ND1 gene is TTG, instead of ATN. All transfer RNAs (tRNAs) exhibit a stable canonical clover‐leaf structure, except for tRNA^Ser(AGN), the dihydrouridine arm of which forms a simple loop. The 1703‐bp long A+T‐rich region is the second longest among the complete adephagan mitogenome sequences, next to Macrogyrus oblongus belonging to Gyrinoidea. One of the unusual features of the genome is the presence of a tRNA^Leu(UUR)‐like sequence in the A+T‐rich region. This sequence displays the proper anticodon sequence and the potential to form secondary structures, but also harbors many mismatches in the stems.     

The mitochondrial genome of the quiet-calling katydids, <Emphasis Type="Italic">Xizicus fascipes</Emphasis> (Orthoptera: Tettigoniidae: Meconematinae)

To help determine whether the typical arthropod arrangement was a synapomorphy for the whole Tettigoniidae, we sequenced the mitochondrial genome (mitogenome) of the quiet-calling katydids, Xizicus fascipes (Orthoptera: Tettigoniidae: Meconematinae). The 16,166-bp nucleotide sequences of X. fascipes mitogenome contains the typical gene content, gene order, base composition, and codon usage found in arthropod mitogenomes. As a whole, the X. fascipes mitogenome contains a lower A+T content (70.2%) found in the complete orthopteran mitogenomes determined to date. All protein-coding genes started with a typical ATN codon. Ten of the 13 protein-coding genes have a complete termination codon, but the remaining three genes (COIII, ND5 and ND4) terminate with incomplete T. All tRNAs have the typical clover-leaf structure of mitogenome tRNA, except for tRNA(Ser(AGN)), in which lengthened anticodon stem (9 bp) with a bulged nuleotide in the middle, an unusual T-stem (6 bp in constrast to the normal 5 bp), a mini DHU arm (2 bp) and no connector nucleotides. In the A+T-rich region, two (TA)n conserved blocks that were previously described in Ensifera and two 150-bp tandem repeats plus a partial copy of the composed at 61 bp of the beginning were present. Phylogenetic analysis found: i) the monophyly of Conocephalinae was interrupted by Elimaea cheni from Phaneropterinae; and ii) Meconematinae was the most basal group among these five subfamilies.     

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.     

Odorant binding protein diversity and distribution among the insect orders, as indicated by LAP, an OBP-related protein of the true bug Lygus lineolaris (Hemiptera, Heteroptera)

Insect odorant binding proteins (OBPs) are thought to deliver odors to olfactory receptors, and thus may be the first biochemical step in odor reception capable of some level of odor discrimination. OBPs have been identified from numerous species of several insect orders, including Lepidoptera, Diptera, Coleoptera and Hymenoptera; all are holometabolous insects belonging to the monophyletic division of insects known as the Endopterygota. Recently, an antennal protein with OBP-like properties was identified from Lygus lineolaris, a hemipteran insect representing the Hemipteroid Assemblage, a sister division to the Endopterygota. The full length sequence of Lygus antennal protein (LAP) is presented in this report. In situ hybridization analysis revealed LAP expression in cell clusters associating with olfactory sensilla; expression was adult-specific, initiating in developing adult tissue during the transitional period that precedes the actual adult molt. Sequence analysis confirmed that LAP is homologous with the OBP-related protein family, and most similar to the OS-E and OS-F proteins of Drosophila, the ABPX proteins of Lepidoptera and the OBPRP proteins of the Coleoptera. Assuming that the OBP-related proteins represent one homologous family, the identification of LAP significantly expands the phylogenetic depth of that family and its underlying role in odor detection to encompass all members of the Endopterygota and Hemipteroid Assemblage, which comprise >90% of all insect species.     

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.     

Phylogenetic and genomic analysis of the complete mitochondrial DNA sequence of the spotted asparagus beetle Crioceris duodecimpunctata

We report the complete mitochondrial DNA sequence of the spotted asparagus beetle, Crioceris duodecimpunctata. The genome complement, gene order, and nucleotide composition of this beetle's mitochondrial genome were found to be typical of those reported for other insects. Unusual features of this genome include the substitution of UCU for GCU as the anticodon for tRNA(Ser), an unusual TpsiC loop for the tRNA(Ile) gene, and the identification of a putative ATT start codon for cox1. The utility of complete mitochondrial genome data for phylogenetic inference of the insect orders was tested, and compared to that of cox1 and combined mitochondrial ribosomal DNA sequences. Even though the number of insect orders represented by complete mitochondrial genomes is still limited, several well-established relationships are evident in the phylogenetic analysis of the complete sequences. Monophyly of the orders Diptera, Lepidoptera, and Coleoptera were consistently recovered. Monophyly of the Holometabola was also observed in some (though not all) analyses. The accumulation of complete mitochondrial sequences from a broader array of insect orders holds the promise of clarifying the early diversification of insects.     

The complete mitochondrial genome of the yellow coaster, <Emphasis Type="Italic">Acraea</Emphasis> <Emphasis Type="Italic">issoria</Emphasis> (Lepidoptera: Nymphalidae: Heliconiinae: Acraeini): sequence,gene organization and a unique tRNA translocation event

In this paper, the complete mitochondrial genome of Acraea issoria (Lepidoptera: Nymphalidae: Heliconiinae: Acraeini) is reported; a circular molecule of 15,245 bp in size. For A. issoria, genes are arranged in the same order and orientation as the complete sequenced mitochondrial genomes of the other lepidopteran species, except for the presence of an extra copy of tRNA^Ile(AUR)b in the control region. All protein-coding genes of A. issoria mitogenome start with a typical ATN codon and terminate in the common stop codon TAA, except that COI gene uses TTG as its initial codon and terminates in a single T residue. All tRNA genes possess the typical clover leaf secondary structure except for tRNA^Ser(AGN), which has a simple loop with the absence of the DHU stem. The sequence, organization and other features including nucleotide composition and codon usage of this mitochondrial genome were also reported and compared with those of other sequenced lepidopterans mitochondrial genomes. There are some short microsatellite-like repeat regions (e.g., (TA)₉, polyA and polyT) scattered in the control region, however, the conspicuous macro-repeats units commonly found in other insect species are absent.     

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 the damsel bug Alloeorhynchus bakeri (Hemiptera: Nabidae)

The complete sequence of the mitochondrial DNA (mtDNA) of the damsel bug, Alloeorhynchus bakeri, has been completed and annotated in this study. It represents the first sequenced mitochondrial genome of heteropteran family Nabidae. The circular genome is 15, 851 bp in length with an A+T content of 73.5%, contains the typical 37 genes that are arranged in the same order as that of the putative ancestor of hexapods. Nucleotide composition and codon usage are similar to other known heteropteran mitochondrial genomes. All protein-coding genes (PCGs) use standard initiation codons (methionine and isoleucine), except COI, which started with TTG. Canonical TAA and TAG termination codons are found in eight protein-coding genes, the remaining five (COI, COII, COIII, ND5, ND1) have incomplete termination codons (T or TA). PCGs of two strands present opposite CG skew which is also reflected by the nucleotide composition and codon usage. All tRNAs have the typical clover-leaf structure, except the dihydrouridine (DHU) arm of tRNA(Ser (AGN))which forms a simple loop as known in many other metazoa. Secondary structure models of the ribosomal RNA genes of A. bakeri are presented, similar to those proposed for other insect orders. There are six domains and 45 helices and three domains and 27 helices in the secondary structures of rrnL and rrnS, respectively. The major non-coding region (also called control region) between the small ribosomal subunit and the tRNA(Ile )gene includes two special regions. The first region includes four 133 bp tandem repeat units plus a partial copy of the repeat (28 bp of the beginning), and the second region at the end of control region contains 4 potential stem-loop structures. Finally, PCGs sequences were used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analyses highly support Nabidae as the sister group to Anthocoridae and Miridae.     

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 genome of the Teinopalpus aureus guangxiensis (Lepidoptera: Papilionidae) and related phylogenetic analyses

In this study, we sequenced the complete mitochondrial genome of Teinopalpus aureus guangxiensis (Lepidoptera: Papilionidae), which is considered as an endemic species in China. It is listed as a vulnerable species by International Union for Conservation of Nature and Natural Resources Red List and also a first class endangered species in China. The complete mtDNA from T. aureus guangxiensis was 15,235 base pairs in length and contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a control region. The T. aureus guangxiensis genes were in the same order and orientation as the completely sequenced mitogenomes of other lepidopteran species. All PCGs of T. aureus guangxiensis mitogenome start with a typical ATN codon and terminate in the common stop codon TAA, except that ND1 gene uses TTA, ND3 gene uses ATT, and ND4 and ND4L gene use TAA. The phylogenetic relationships were reconstructed with the concatenated sequences of the 13 PCGs of the mitochondrial genome, and phylogenetic results confirmed that Nymphalidae, Lycaenidae, Papilionidae, Pieridae are monophyletic clades.     

黄脸油葫芦线粒体基因组:一种新的基因排列方式

采用长距PCR扩增及保守引物步移法测定并注释了黄脸油葫芦（Teleogryllus emma）线粒体基因组全序列。结果表明,黄脸油葫芦的线粒体基因组全长15 660 bp,A+T含量为73.1%。谷氨酸、色氨酸及天冬酰胺的转运RNA基因由N链编码,形成了直翅目中的第三种基因排列顺序,其余结构与其它螽亚目昆虫的线粒体结构一致。基因间隔序列共计73 bp,间隔长度从1—24 bp不等;有14对基因间存在共54 bp重叠,重叠碱基数在1—11 bp之间。13个蛋白质编码基因中12个基因（除COⅠ基因外）的起始密码为标准的ATN组成,COI基因的起始密码子为TTA。有10个基因在基因3＇端能找到完全的TAA或TAG终止密码子,而有三个基因（COII,ND5和ND4）终止密码子为不完整的T。除tRNASer（AGN）外,其余21个tRNA基因的二级结构均属典型的三叶草结构。黄脸油葫芦940bp的A+T富集区中存在一个被认为与复制起始有关的保守的二级结构,该结构不仅存在于直翅目昆虫中,而且也存在于双翅目、鳞翅目和膜翅目中,但是未见于昆虫纲的早期分化类群——弹尾目中。     

Mytilus mitochondrial DNA contains a functional gene for a tRNASer(UCN) with a dihydrouridine arm-replacement loop and a pseudo-tRNASer(UCN) gene.

A 2500-nucleotide pair (ntp) sequence of F-type mitochondrial (mt) DNA of the Pacific Rim mussel Mytilus californianus (class Bivalvia, phylum Mollusca) that contains two complete (ND2 and ND3) and two partial (COI and COIII) protein genes and nine tRNA genes is presented. Seven of the encoded tRNAs (Ala, Arg, His, Met(AUA), Pro, Ser(UCN), and Trp) have the potential to fold into the orthodox four-armed tRNA secondary structure, while two [tRNASer(AGN) and a second tRNASer(UCN)] will fold only into tRNAs with a dihydrouridine (DHU) arm-replacement loop. Comparison of these mt-tRNA gene sequences with previously published, corresponding M. edulis F-type mtDNA indicates that similarity between the four-armed tRNASer(UCN) genes is only 63.8% compared with an average of 92.1% (range 86.2-98. 5%) for the remaining eight tRNA genes. Northern blot analysis indicated that mature tRNAs encoded by the DHU arm-replacement loop-containing tRNASer(UCN), tRNASer(AGN), tRNAMet(AUA), tRNATrp, and tRNAPro genes occur in M. californianus mitochondria, strengthening the view that all of these genes are functional. However, Northern blot and 5' RACE (rapid amplification of cDNA ends) analyses indicated that the four-armed tRNASer(UCN) gene is transcribed into a stable RNA that includes the downstream COI sequence and is not processed into a mature tRNA. On the basis of these observations the M. californianus and M. edulis four-armed tRNASer(UCN) sequences are interpreted as pseudo-tRNASer(UCN) genes.     

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。