Mitochondrial DNA sequence of yellow catfish (Pelteobagrus fulvidraco)

Yellow catfish (Pelteobagrus fulvidraco) belongs to the family Bagridae, which is one of the most important economic freshwater aquaculture species in China. In this study, we reported the complete sequence of the mitochondrial genome of P. fulvidraco. The complete mitochondrial genome is 16,527 bp in length, including the typical structure of 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes, and the non-coding control region. Both the termination-associated sequence and critical central conserved sequences (CSB-D, CSB-E, and CSB-F) was also detected.     

Complete mitochondrial DNA sequence of the Japanese spiny lobster,Panulirus japonicus (Crustacea: Decapoda)

We determined the complete nucleotide sequence of the mitochondrial genome for a Japanese spiny lobster, Panulirus japonicus (Crustacea: Decapoda). The entire genome was amplified using long polymerase chain reaction, and the products were subsequently used as templates for direct sequencing using a primer-walking strategy. The genome (15,717 base pairs) contained the same 37 genes (two ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes) plus the putative control region as found in other arthropods, with the gene order identical to that of typical arthropods. Preliminary phylogenetic analyses of selected arthropods using concatenated amino acid sequences of the 13 protein-coding genes strongly supported monophyly of Decapoda species and confidently rejected "Macroura", a conventional taxon that shares an elongated abdominal body.     

中国地鼠线粒体基因组的序列分析与分子进化

目的 获得中国地鼠线粒体基因组序列,为线粒体疾病模型提供分子数据.方法 参照近缘物种的线粒体基因组序列,设计27对特异引物,采用TD-PCR及测序技术获得了中国地鼠的线粒体全基因组序列,分析了其基因组特点和各基因的定位.还结合GenBank中已发表的其他5种啮齿类动物的线粒体基因组序列,探讨啮齿类动物不同科间的系统进化关系.结果 中国地鼠线粒体基因组全长为16 283 bp,碱基组成为33.53％A、30.50％T、12.98％G、22.80％C,包括13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个非编码基因控制区.中国地鼠和金黄地鼠亲缘关系最近.结论 中国地鼠线粒体基因组各基因长度、位置与典型的啮齿类动物相似,其编码蛋白质区域和rRNA基因与其他啮齿类动物具有很高的同源性,显示线粒体基因组在进化上十分保守.5种动物的分子系统进化树与传统分类地位一致.     

Complete mitochondrial genome of the miiuy croaker Miichthys miiuy (Perciformes, Sciaenidae) with phylogenetic consideration

The complete sequence of the 16,493 nucleotide mitochondrial genome from the single species of the family Sciaenidae, the miiuy croaker, Miichthys miiuy, was determined. The nucleotide sequences of M. miiuy mitochondrial DNA have been compared with those of three other Sciaenidae fishes. The contents of the M. miiuy mitochondrial genome are 13 protein-coding genes, two ribosomal RNA genes and 22 transfer RNA genes, and two non-coding regions (L-strand replication origin and control region), the gene order of which is identical to that observed in most vertebrates. The L-strand replication origin of M. miiuy is not pyrimidine-rich compared to those of most bony fishes. Within the control region, we identified the extended termination associated sequence domain, the central conserved sequence block domain and the conserved sequence block domain, while the typical central conserved blocks CSB-D, -E and -F could not be detected in the three other Sciaenidae species. In the ML phylogenetic analyses, the monophyly of Pseudosciaeniae was not supported, which is against with the morphological results. Collichthys niveatus is most closely related to Larimichthys polyactis, and Collichthys and Larimichthys may be merged into one genus, based on the current datasets.     

枣食芽象甲线粒体基因组全序列测定与系统发育分析

【目的】从线粒体基因组水平上探讨枣食芽象甲Scythropus yasumatsui与近缘种的系统发育关系。【方法】利用Illumina MiSeq测序平台对枣食芽象甲线粒体基因组进行测序,对基因组序列进行拼装、注释和特征分析;利用贝叶斯法和最大似然法构建基于象甲科13个物种的线粒体基因组13个蛋白质编码基因核苷酸序列的系统发育树。【结果】结果表明,枣食芽象甲线粒体基因组全长为16 472 bp (GenBank登录号: MF807224),包含13个蛋白质编码基因、22个tRNA基因、2个rRNA基因和2个非编码控制区,37个基因的排列顺序与祖先昆虫的线粒体基因排列顺序一致。13个蛋白质编码基因的起始密码子为ATN,其中除了cob和nad1基因的完全终止密码子为TAG外,其余11个基因的完全终止密码子为TA(A)。22个tRNA基因中除了trnS1缺少DHU臂,反密码子由GCT变为TCT外,其余均能形成典型的三叶草结构。基于13个蛋白质编码基因序列构建的系统发育树结果显示,象甲科8个亚科系统发育关系为：(((隐喙象亚科(Cryptorhynchinae)+(象虫亚科(Curculioninae)+魔喙象亚科(Molytinae)))+长小蠹亚科(Platypodinae))+(粗喙象亚科(Entiminae)+Cyclominae亚科))+隐颏象亚科(Dryophthorinae)+小蠹亚科(Scolytinae))。【结论】在13种象甲科昆虫物种中,同属于粗喙象亚科的枣食芽象甲与南美果树象甲Naupactus xanthographus在系统发育树中聚为同一分支,表明基于线粒体基因组全序列的分子系统发育结果与传统的形态分类结果是一致的。     

Organization of the Mitochondrial Genome of a Deep-Sea Fish, Gonostoma gracile (Teleostei: Stomiiformes): First Example of Transfer RNA Gene Rearrangements in Bony Fishes

We determined the complete nucleotide sequence of the mitochondrial genome (except for a portion of the putative control region) for a deep-sea fish, Gonostoma gracile. The entire mitochondrial genome was purified by gene amplification using long polymerase chain reaction (long PCR), and the products were subsequently used as templates for PCR with 30 sets of newly designed, fish-universal primers that amplify contiguous, overlapping segments of the entire genome. Direct sequencing of the PCR products showed that the genome contained the same 37 mitochondrial structural genes as found in other vertebrates (two ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes), with the order of all rRNA and protein-coding genes, and 19 tRNA genes being identical to that in typical vertebrates. The gene order of the three tRNAs (tRNA^Glu, tRNA^Thr, and tRNA^Pro) relative to cytochrome b, however, differed from that determined in other vertebrates. Two steps of tandem duplication of gene regions, each followed by deletions of genes, can be invoked as mechanisms generating such rearrangements of tRNAs. This is the first example of tRNA gene rearrangements in a bony fish mitochondrial genome. Received August 5, 1998; accepted February 19, 1999.     

Complete mitochondrial genome of the Asian paddle crab <Emphasis Type="Italic">Charybdis japonica</Emphasis> (Crustacea: Decapoda: Portunidae): gene rearrangement of the marine brachyurans and phylogenetic considerations of the decapods

Given the commercial and ecological importance of the Asian paddle crab, Charybdis japonica, there is a clearly need for genetic and molecular research on this species. Here, we present the complete mitochondrial genome sequence of C. japonica, determined by the long-polymerase chain reaction and primer walking sequencing method. The entire genome is 15,738 bp in length, encoding a standard set of 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, plus the putative control region, which is typical for metazoans. The total A+T content of the genome is 69.2%, lower than the other brachyuran crabs except for Callinectes sapidus. The gene order is identical to the published marine brachyurans and differs from the ancestral pancrustacean order by only the position of the tRNA ^His gene. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of 13 protein-coding genes strongly support the monophyly of Dendrobranchiata and Pleocyemata, which is consistent with the previous taxonomic classification. However, the systematic status of Charybdis within subfamily Thalamitinae of family Portunidae is not supported. C. japonica, as the first species of Charybdis with complete mitochondrial genome available, will provide important information on both genomics and molecular ecology of the group.     

Complete Mitochondrial DNA Sequence of Tigriopus japonicus (Crustacea: Copepoda)

The complete nucleotide sequence of the mitochondrial genome was determined for a harpacticoid copepod, Tigriopus japonicus (Crustacea), using an approach that employs a long polymerase chain reaction technique and primer walking. Although the genome (14,628 bp) contained the same set of 37 genes (2 ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes) as found in other metazoan animals, none of the previously reported gene orders were comparable to that of T. japonicus. Furthermore, all genes were encoded on one strand, unlike the mitochondrial genomes of most metazoan animals. Size reductions were notable for tRNA and rRNA genes, resulting in one of the smallest mitochondrial genomes in the arthropod lineage. Although it appears that such large-scale gene rearrangements have occurred in the ancestral species of T. japonicus, none of the proposed mechanisms parsimoniously account for this eccentric gene arrangement.     

大紫蛱蝶线粒体基因组全序列分析

通过PCR步移法对大紫蛱蝶Sasakia charonda coreana线粒体基因组全序列进行了测定和分析。分析结果表明:大紫蛱蝶线粒体基因组全长15233bp,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381bp的非编码区。A、T、C、G碱基含量分别为39.7%、40.2%、12.2%、7.9%。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鳞翅目昆虫相同。13个蛋白编码基因中除COⅠ以CGA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COⅡ和ND4以单独的T作为终止密码子。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。与其它多数鳞翅目昆虫一样,大紫蛱蝶的非编码区序列中散在着一些长短不一的串联重复单元,在与其近缘物种非编码区的比较当中并未发现共同的保守序列区。     

Complete mitochondrial genome of the Bewick's swan Cygnus columbianus bewickii (Aves, Anseriformes, Anatidae)

The mitochondrial genome of Bewick's swan Cygnus columbianus bewickii was completely sequenced and then the resultant data were compared with those of the whistling swan Cygnus columbianus columbianus. The complete mitochondrial genome sequence of C. c. bewickii was 16,727?bp in length and its gene arrangement pattern, gene content, and genome organization were identical to those of Cygnus species. The similarities of nucleotide and amino acid sequences between the two swans were 99.1% and 99.6%, respectively. Out of the 13 protein-coding genes and 2 rRNA genes, COIII showed the lowest nucleotide sequence similarity with 98.0%. On the other hand, in amino acid sequence similarities, both COII and ATP6 showed the lowest with 98.7% in common. The control region has the 97.8% nucleotide sequence similarity.     

The Mitochondrial Genome of Paramphistomum cervi (Digenea), the First Representative for the Family Paramphistomidae

We determined the complete mitochondrial DNA (mtDNA) sequence of a fluke, Paramphistomum cervi (Digenea: Paramphistomidae). This genome (14,014 bp) is slightly larger than that of Clonorchis sinensis (13,875 bp), but smaller than those of other digenean species. The mt genome of P. cervi contains 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (NCRs), a complement consistent with those of other digeneans. The arrangement of protein-coding and ribosomal RNA genes in the P. cervi mitochondrial genome is identical to that of other digeneans except for a group of Schistosoma species that exhibit a derived arrangement. The positions of some transfer RNA genes differ. Bayesian phylogenetic analyses, based on concatenated nucleotide sequences and amino-acid sequences of the 12 protein-coding genes, placed P. cervi within the Order Plagiorchiida, but relationships depicted within that order were not quite as expected from previous studies. The complete mtDNA sequence of P. cervi provides important genetic markers for diagnostics, ecological and evolutionary studies of digeneans.     

绿眼赛茧蜂线粒体基因组全序列测定和分析

【目的】测定绿眼赛茧蜂Zele chlorophthalmus线粒体基因组全序列,分析其基因组结构及茧蜂科(Braconidae)部分类群的系统发育关系。【方法】利用Illumina MiSeq二代测序技术对绿眼赛茧蜂的线粒体基因组进行测序,对基因组序列进行拼装、注释,分析其结构特点和碱基组成;基于22种茧蜂科昆虫的COX1蛋白编码基因序列,应用最大似然法(ML)和邻接法(NJ)构建系统发育树,分析绿眼赛茧蜂与茧蜂科其他昆虫的系统发育关系。【结果】绿眼赛茧蜂线粒体基因组全长16 661 bp(GenBank登录号: MG822749),包含13个蛋白质编码基因、22个tRNA基因和2个rRNA基因,共37个基因,以及1个控制区。线粒体基因组有明显的核苷酸组成的偏倚,AT偏正,GC偏负,其A+T含量为82.83%。基因排列顺序与推测的昆虫祖先的序列不完全一致,tRNA基因7处发生重排。13个蛋白质编码基因均以ATN为起始密码子,以TAA为终止密码子。在22个tRNA基因二级结构中,除tRNA^His(H)缺失TΨC环和tRNA^Cys(C)仅剩二氢尿嘧啶(DHU)臂和反密码子臂外,其余tRNA基因均能形成典型的三叶草结构。基于COX1蛋白编码序列的系统发育分析结果显示,与绿眼赛茧蜂亲缘关系最近的是同属于赛茧蜂属的雪跗赛茧蜂Z. niveitarsis。【结论】本研究首次获得绿眼赛茧蜂线粒体基因组全序列。结果表明绿眼赛茧蜂隶属于优茧蜂亚科(Euphorinae)赛茧蜂属,并支持赛茧蜂属的单系性。     

The Complete Mitochondrial Genomes of Three Bristletails (Insecta: Archaeognatha): The Paraphyly of Machilidae and Insights into Archaeognathan Phylogeny

The order Archaeognatha was an ancient group of Hexapoda and was considered as the most primitive of living insects. Two extant families (Meinertellidae and Machilidae) consisted of approximately 500 species. This study determined 3 complete mitochondrial genomes and 2 nearly complete mitochondrial genome sequences of the bristletail. The size of the 5 mitochondrial genome sequences of bristletail were relatively modest, containing 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and one control region. The gene orders were identical to that of Drosophila yakuba and most bristletail species suggesting a conserved genome evolution within the Archaeognatha. In order to estimate archaeognathan evolutionary relationships, phylogenetic analyses were conducted using concatenated nucleotide sequences of 13 protein-coding genes, with four different computational algorithms (NJ, MP, ML and BI). Based on the results, the monophyly of the family Machilidae was challenged by both datasets (W12 and G12 datasets). The relationships among archaeognathan subfamilies seemed to be tangled and the subfamily Machilinae was also believed to be a paraphyletic group in our study.     

The mitochondrial genome of Strongyloides stercoralis (Nematoda) - idiosyncratic gene order and evolutionary implications

The complete mitochondrial genome sequence of the parasitic nematode Strongyloides stercoralis was determined, and its organisation and structure compared with other nematodes for which complete mitochondrial sequence data were available. The mitochondrial genome of S. stercoralis is 13,758 bp in size and contains 36 genes (all transcribed in the clockwise direction) but lacks the atp8 gene. This genome has a high T content (55.9%) and a low C content (8.3%). Corresponding to this T content, there are 16 (poly-T) tracts of >/=12 Ts distributed across the genome. In protein-coding genes, the T bias is greatest (76.4%) at the third codon position compared with the first and second codon positions. Also, the C content is higher at the first (9.3%) and second (13.4%) codon positions than at the third (2%) position. These nucleotide biases have a significant effect on predicted codon usage patterns and, hence, on amino acid compositions of the mitochondrial proteins. Interestingly, six of the 12 protein-coding genes are predicted to employ a unique initiation codon (TTT), which has not yet been reported for any other animal mitochondrial genome. The secondary structures predicted for the 22 transfer RNA (trn) genes and the two ribosomal RNA (rrn) genes are similar to those of other nematodes. In contrast, the gene arrangement in the mitochondrial genome of S. stercoralis is different from all other nematodes studied to date, revealing only a limited number of shared gene boundaries (atp6-nad2 and cox2-rrnL). Evolutionary analyses of mitochondrial nucleotide and amino acid sequence data sets for S. stercoralis and seven other nematodes demonstrate that the mitochondrial genome provides a rich source of phylogenetically informative characters. In conclusion, the S. stercoralis mitochondrial genome, with its unique gene order and characteristics, should provide a resource for comparative mitochondrial genomics and systematics studies of parasitic nematodes.     

Complete mitochondrial DNA sequence of Aulopus japonicus (Teleostei: Aulopiformes), a basal Eurypterygii: longer DNA sequences and higher-level relationships

For the first step toward resolution of the higher-level relationships of the order Aulopiformes (Teleostei: Eurypterygii) using longer DNA sequences, we determined the complete mitochondrial DNA sequence for Aulopus japonicus (Aulopodidae). The entire genome was purified by gene amplification using a long PCR technique, and the products were subsequently used as templates for PCR with 63 fish-versatile and 3 species-specific primers that amplify contiguous, overlapping segments of the entire genome. Direct sequencing of the PCR products demonstrated that the genome (16 653 base pairs [bp]) contained the same 37 mitochondrial genes (2 ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes) as found in other vertebrates, with the gene order identical to that in typical vertebrates. Maximum-parsimony analysis using nucleotide sequences from the concatenated 12 protein-coding genes (no third codon positions and excluding the ND6 gene) plus 22 tRNA genes (stem regions only) from eight teleosts placed A. japonicus in a reasonable phylogenetic position; those from individual protein-coding genes and the concatenated 22 tRNA genes alone, however, did not reproduce the expected phylogeny with few exceptions, probably owing to insufficient phylogenetic information in these smaller data sets. This result suggests that further taxonomic sampling and sequencing efforts may clarify limits and intra- and interrelationships of this morphologically and ecologically diverse group of fishes using mitochondrial genomic (mitogenomic) data. Received: August 31, 2000 / Revised: December 20, 2000 / Accepted: January 23, 2001     

Complete sequence of the Tibetan Mastiff mitochondrial genome and its phylogenetic relationship with other Canids ( Canis, Canidae)

In this study, the complete sequence of the Tibetan Mastiff mitochondrial genome (mtDNA) was determined, and the phylogenetic relationships between the Tibetan Mastiff and other species of Canidae were analyzed using the coyote (Canis latrans) as an outgroup. The complete nucleotide sequence of the Tibetan Mastiff mtDNA was 16 710 bp, and included 22 tRNA genes, 2S rRNA gene, 13 protein-coding genes and one non-coding region (D-loop region), which is similar to other mammalian mitochondrial genomes. The characteristics of the protein-coding genes, non-coding region, tRNA and rRNA genes among Canidae were analyzed in detail. Neighbor-joining and maximum-parsimony trees of Canids constructed using 12 mitochondrial protein-coding genes showed that as the coyotes and Tibetan wolves clustered together, so too did the gray wolves and domestic dogs, suggesting that the Tibetan Mastiff originated from the gray wolf as did other domestic dogs. Domestic dogs clustered into four clades, implying at least four maternal origins (A to D). The Tibetan Mastiff, which belongs to clade A, appears to be closely related to the Saint Bernard and the Old English Sheepdog.     

Mitochondrial genome sequence of the shining catfish (Pelteobagrus nitidus)

The complete mitochondrial DNA sequence of Pelteobagrus nitidus was determined using a PCR-based method. The total length of mitochondrial DNA is 16,532 bp. The contents of the P. nitidus mitochondrial genome are 13 protein-coding genes, two ribosomal RNA and 22 transfer RNA genes, and a non-coding control region. Base composition of the entire genome is A 31.72%, T 26.92%, C 26.45%, and G 14.91%, with an A+T (58.64%) rich feature as that of other vertebrate mitochondrial genome.     

The complete mitochondrial genome sequence and gene organization of the mud crab (Scylla paramamosain) with phylogenetic consideration

The complete mitochondrial genome is of great importance for better understanding the genome-level characteristics and phylogenetic relationships among related species. In the present study, we determined the complete mitochondrial genome DNA sequence of the mud crab (Scylla paramamosain) by 454 deep sequencing and Sanger sequencing approaches. The complete genome DNA was 15,824 bp in length and contained a typical set of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and a putative control region (CR). Of 37 genes, twenty-three were encoded by the heavy strand (H-strand), while the other ones were encoded by light strand (L-strand). The gene order in the mitochondrial genome was largely identical to those obtained in most arthropods, although the relative position of gene tRNA^His differed from other arthropods. Among 13 protein-coding genes, three (ATPase subunit 6 (ATP6), NADH dehydrogenase subunits 1 (ND1) and ND3) started with a rare start codon ATT, whereas, one gene cytochrome c oxidase subunit I (COI) ended with the incomplete stop codon TA. All 22 tRNAs could fold into a typical clover-leaf secondary structure, with the gene sizes ranging from 63 to 73 bp. The phylogenetic analysis based on 12 concatenated protein-coding genes showed that the molecular genetic relationship of 19 species of 11 genera was identical to the traditional taxonomy.     

The mitochondrial genome of spotted green pufferfish Tetraodon nigroviridis (Teleostei: Tetraodontiformes) and divergence time estimation among model organisms in fishes

We determined the whole mitochondrial genome sequence for spotted green pufferfish, Tetraodon nigroviridis (Teleostei: Tetraodontiformes). The genome (16,488 bp) contained 37 genes (two ribosomal RNA genes, 22 transfer RNA genes, and 13 protein-coding genes) plus control region as found in other vertebrates, with the gene order identical to that of typical vertebrates. The sequence was used to estimate phylogenetic relationships and divergence times among major lineages of fishes, including representative model organisms in fishes. We employed partitioned Bayesian approaches for these two analyses using two datasets that comprised concatenated amino acid sequences from 12 protein-coding genes (excluding the ND6 gene) and concatenated nucleotide sequences from the 12 protein-coding genes (without 3rd codon positions), 22 transfer RNA genes, and two ribosomal RNA genes. The resultant trees from the two datasets were well resolved and largely congruent with those from previous studies, with spotted green pufferfish being placed in a reasonable phylogenetic position. The approximate divergence times between spotted green pufferfish and model organisms in fishes were 85 million years ago (MYA) vs. torafugu, 183 MYA vs. three-spined stickleback, 191 MYA vs. medaka, and 324 MYA vs. zebrafish, all of which were about twice as old as the divergence times estimated by their earliest occurrences in fossil records.