Origin Of Light Strand Replication Research Articles

The complete mitochondrial genome sequence of Acentrogobius sp. (Gobiiformes: Gobiidae) and phylogenetic studies of Gobiidae

At present, few morphological descriptions are available for Acentrogobius species and there exist some confused issues on the species classification and phylogeny. In this study, we first determined and described the complete mitochondrial genome of Acentrogobius sp. The complete mitogenome sequence is 17 083 bp in length, containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, a putative control region (CR), and a light-strand replication origin (OL). The overall base composition is 28.9% A, 26.2% T, 28.5% C, and 16.4% G, with a slight AT bias (55.1%). To furthermore validate the new determined sequences, phylogenetic trees involving all the Gobiidae species available in GenBank database were constructed. These results are expected to provide useful molecular data for species identification and further phylogenetic studies of Gobiiformes.

The complete mitochondrial genome sequence of Plotosus japonicus (Siluriformes: Plotosidae) and phylogenetic studies of Siluriformes

In this study, we first determined and described the complete mitogenome sequence of Plotosus japonicus, which is a kind of marine fish widely distributed in Northwest Pacific. The complete mitogenome sequence is 16 472 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, a putative control region (CR) and a light-strand replication origin (OL). The overall base composition is 31.9% A, 24.7% T, 27.7% C, 15.7% G, with a slight AT bias (56.6%), similar to other vertebrate mitochondrial genomes. All the protein-coding genes use the initiation codon ATG except COI uses GTG. Most of them have TAA or TAG as the stop codon, while COII and ND4 use AGA, COIII and Cytb use an incomplete stop codon TA or T. Maximum Likelihood (ML) tree and Bayesian analyses based on concatenated nucleotide sequences of 12 mitochondrial protein-coding genes were constructed and both yielded identical topologies. These results are expected to provide useful molecular data for species identification and further phylogenetic studies of Siluriformes.

Sequence and organization of the complete mitochondrial genome of Schizothorax davidi (Teleostei: Cypriniformes: Cyprinidae)

In this study, we determined the complete mitochondrial genome sequence of Schizothorax davidi. The length of the genome is 16,577 bp, which contains 13 protein coding genes, 22 transfer RNAs, two ribosomal RNAs, and two non-coding regions: control region (D-loop) and origin of light-strand replication (OL). The complete mitochondrial DNA sequence of S. davidi provides useful genetic markers for the studies on molecular systematic, population genetics, and phylogeography.

The complete mitochondrial genome of Chaenogobius gulosus (Gobiidae, Perciformes) from the South Sea, Korea

The morphology-based taxonomy of Chaenogobius is so complex that some species have been transferred to other genera. To obtain basic information on the phylogenetic relationships among gobies, the complete mitochondrial DNA sequence of C. gulosus was determined using next-generation sequencing. The complete mitochondrial genome is 16,477 bp in length and consists of 22 tRNAs, two ribosomal RNAs, 13 protein-coding genes, and two non-coding regions (the light strand replication origin and the control region). The gene order and locations are similar to those in most other vertebrates. The nucleotide composition of the mitogenome contains 29.1% A, 29.6% T, 15.9% G, and 25.4% C, with a slight AT bias (58.7%). The genus most related to Chaenogobius was Luciogobius, as revealed by phylogenetic relationships derived using a maximum likelihood tree. This mitogenome will help to elucidate the morphological systematic complexity and phylogenetic structure of Chaenogobius and related species.

Triplex real-time PCR--an improved method to detect a wide spectrum of mitochondrial DNA deletions in single cells.

Mitochondrial DNA (mtDNA) mutations are commonly found in the skeletal muscle of patients with mitochondrial disease, inflammatory myopathies and sarcopenia. The majority of these mutations are mtDNA deletions, which accumulate to high levels in individual muscle fibres causing a respiratory defect. Most mtDNA deletions are major arc deletions with breakpoints located between the origin of light strand (OL) and heavy strand (OH) replication within the major arc. However, under certain disease conditions, rarer, minor arc deletions are detected. Currently, there are few techniques which would allow the detection and quantification of both types of mtDNA deletions in single muscle fibres. We have designed a novel triplex real-time PCR assay which simultaneously amplifies the MT-ND4 gene in the major arc, the MT-ND1 gene in the minor arc, and the non-coding D-Loop region. We demonstrate that this assay is a highly sensitive and reliable tool for the detection and quantification of a broad range of major and minor arc mtDNA deletions with the potential to investigate the molecular pathogenesis in both research and diagnostic settings.

The complete mitochondrial genome sequence of Schizothorax lissolabiatus (Cypriniformes: Cyprinidae)

Schizothorax lissolabiatus is a widely distributed fish species in Lancang River, Yuanjiang River, Pearl River, Nujiang River in China. The complete mitochondrial genome sequence of S. lissolabiatus from Yuanjiang River (the upper Red River) has been sequenced, which is 16,583 bp in length and contains 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and 2 main non-coding regions: origin of light-strand replication and control region. Except for eight tRNA and ND6 genes, most of the genes are encoded on the heavy strand. The length of mitochondrial genome, the order, composition and anticodons of all genes are exactly similar to that of S. dolichonema. The phylogenetic tree suggested S. prenanti, S. dolichonema and S. lissolabiatus may have closer affinities than other fish of the genus Schizothorax.

Tandem Duplication and Random Loss for mitogenome rearrangement in Symphurus (Teleost: Pleuronectiformes).

BackgroundThe mitochondrial genomes (mitogenomes) of flatfishes (Pleuronectiformes) exhibit highly diversified types of large-scale gene rearrangements. We have reported that the mitogenomes of Crossorhombus azureus (Bothidae), Samariscus latus (Samaridae) and Cynoglossus fishes (Cynoglossidae) show different types of gene rearrangements.ResultsIn the present study, the complete mitogenomes of two Symphurus species (Cynoglossidae), Symphurus plagiusa and Symphurus orientalis, were determined. The gene order in the S. plagiusa mitogenome is the same as that of a typical vertebrate (without any gene rearrangements). Surprisingly, large-scale gene rearrangements have occurred in S. orientalis. In the rearranged fragment from the control region (CR) to the WANCY tRNA cluster (tRNA cluster of tRNA-W, tRNA-A, tRNA-N, tRNA-C and tRNA-Y) in the S. orientalis mitogenome, tRNA-V and tRNA-M have been translocated to the 3’ end of the 16S rRNA gene, with six large intergenic spacers over 20 bp in length. In addition, an origin for light-strand replication (OL) structure that is typically located in the WANCY region was absent in both the S. plagiusa and S. orientalis mitogenomes. It is generally recognized that a sequence in the WANCY region that encodes tRNAs forms a hairpin structure (OL-like structure) and can act as the OL when the typical locus is lost. Moreover, an additional OL-like structure was identified near the control region in the S. plagiusa mitogenome.ConclusionsThe positions of the intergenic spacers and the rearranged genes of the S. orientalis mitogenome strongly indicate that the mechanism underlying the rearrangement of this mitogenome was Tandem Duplication and Random Loss. Additionally, two OL-like regions substituting for the typical locus were found in the S. plagiusa mitogenome. We speculate that the ancestral mitogenomes of S. plagiusa and S. orientalis also had this characteristic, such that if both OL-like structures functioned during mitochondrial replication, they could initiate duplicate replications of the light strand (L-strand), leading to duplication of the region between the two structures. We consider that this mechanism may account for the gene duplication that occurred during the gene rearrangement process in the evolution of the ancestral mitogenome to the S. orientalis mitogenome.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1581-6) contains supplementary material, which is available to authorized users.

The complete mitochondrial genome sequence of Beaufortia szechuanensis (Cypriniformes, Balitoridae)

The Beaufortia szechuanensis is endemic to the upper reaches of Yangtze River in China. In this study, we successfully sequenced the mitochondrial genome of the B. szechuanensis, collected from the Qingyi River. The complete mitochondrial genome of B. szechuanensis was a circular molecule of 16,559 bp in length, containing 2 ribosomal RNA (rRNA) genes, 13 protein-coding genes, 22 transfer RNA (tRNA) genes, an origin of light-strand replication (OL) and a control region (D-loop). It is the first complete mitochondrial DNA data in the genus Beaufortia. The cytochrome c oxidase subunit I (COI) sequence of 14 species in Balitoridae was used for phylogenetic analysis. The topology demonstrated that the Balitoridae can be classified into two subfamilies, and the B. szechuanensis belongs to the subfamily Gastromyzoninae.

The complete mitochondrial genome sequence of Schizopygopsis anteroventris (Cypriniformes: Cyprinidae)

Schizopygopsis anteroventris (Cyprinidae: Schizothoracinae) is an ecologically and economically important cyprinid endemic to Qinghai-Tibet Plateau, China. In this study, we sequenced the complete mitochondrial genome of S. anteroventris by DNA sequencing based on PCR fragments. The mitogenome of S. anteroventris is 16,620 in length, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and two non-coding regions: the control region (D-loop) and the origin of light-strand replication (OL). The gene order in the mitogenome is identical with common vertebrate form. The complete mitogenome sequence is useful for further genetic studies, phylogenetic analysis and resource protection of S. anteroventris.

Complete mitochondrial genome of Gnathopogon taeniellus (Cypriniformes: Cyprinidae)

The complete mitochondrial genome of Gnathopogon taeniellus was first determined in this study. It is 16,596 bp in length, contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and one control region in the typical vertebrate gene order and transcriptional direction. There are total of 29 bp short overlaps and 34 bp non-coding intergenic spacers were found in the mitogenome. Overall nucleotide base composition of light strand is 29.3% A, 25.8% C, 17.9% G and 27.0% T. Two start codons (ATG and GTG) and two stop codons (TAG and TAA/T) were used in the protein-coding genes. The origin of light strand replication (OL) was identified between tRNAAsn and tRNACys genes and could fold a hairpin structure. The nucleotide composition of control region is 31.8% A, 20.9% C, 14.0% G and 33.3% T.

Complete mitochondrial genome sequence of the Asian golden cat, Catopuma temminckii

In this study, the mitochondrial genome of Asian golden cat (Catopuma temminckii) is sequenced. The mitochondrial genome was 16,985 bp long, including 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, 1 control region and 1 origin of light-strand replication. The overall base composition of the mitochondrial genome was 32.76% A, 27.49 % T, 25.75 % C, and 13.99 % G. The complete mitochondrial genome of Catopuma temminckii could contribute to understanding taxonomic status and phylogenetic relationship of genus Catopuma.

Characterization of the complete mitochondrial genome of Gymnocypris chilianensis (Teleostei: Cypriniformes: Cyprinidae)

The complete mitochondrial DNA sequence of Gymnocypris chilianensis was determined and analyzed. The mitogenome of G. chilianensis is 16,667 bp long, containing 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 2 non-coding regions: control region (D-loop) and origin of light-strand replication (OL). The gene order of mitogenome is identical to that observed in most other vertebrates. The complete mitogenome sequence information of G. chilianensis can provide useful data for further studies on molecular systematic, taxonomic status, stock evaluation and conservation genetics.

Complete mitochondrial genome of Mugilogobius chulae (Perciformes: Gobiidae)

In this paper, the complete mitogenome sequence of Mugilogobius chulae is reported. The circular mitochondrial DNA of M. chulae is 16,489 bp in length, containing 13 protein-coding genes, 22 tRNAs, 2 rRNAs and 2 non-coding regions (control region and origin of light-strand replication). The overall base composition of M. chulae is 27.8% A, 27.1% T, 16.8% G, 28.3% C. This genome reported here provides a resource for studies on taxonomy and genetics of M. chulae and closely related species.

The complete mitochondrial genome sequence of Colossoma macropomum (Characiformes: Serrasalmidae)

Colossoma macropomum (Cuvier, 1816) is the largest characin of South America. This species and its congeners mainly feed on zooplankton, insects, snails and decaying plants. In this paper, we sequenced and annotated the complete mitogenome of C. macropomum. The total length is 16,703 bp, and it typically consist of 37 genes, including 13 protein-coding genes, two rRNAs, 22 tRNA, a light-strand replication origin (OL) and a large control region (D-loop). The overall base composition is 29.9%, 24.6%, 29.5% and 15.9% for A, T, C and G, respectively, with a slight bias on AT content (54.6%). All protein-coding genes share the start codon ATG, except for COI, which begins with GTG. Most of them have TAA or TAG as the stop codon, except COII, ND4 use AGA and COI, Cytb use an incomplete stop codon T. This information could provide useful molecular data and contribute to further phylogenetic studies of Characiformes and Serrasalmidae.

Complete mitochondrial genome of the Cyclemys dentata and phylogenetic analysis of the major family Geoemydidae.

In the present study, the complete mitochondrial (mt) genome of Cyclemys dentata was determined using PCR reactions. The structural organization and gene order of C. dentata were equivalent to those of most other vertebrates. The mt genome was 16,489 bp in length, has rich A+T content, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region (D-loop). All protein-coding genes started with ATG, many genes have complete stop codons, except ND2, COX3, ND3, and cyt-b genes had incomplete stop codons of T. The light-strand replication origin (OL) of C. dentata might fold into a stable stem-loop secondary structure, and its loop had 2 nt less than that of the Cyclemys atripons OL sequence. The D-Loop of C. dentata contained a central domain (CD), 2 extended termination associated sequences (ETAS1, ETAS2) and 3 conserved sequence blocks (CSB1, CSB2, CSB3). The average length of 20 turtles' mt genomes was 16,692.5 bp, including 34.1% A, 27.0% T, 26.0% C and 12.9% G. The C. dentata mitochondrial genome could provide useful data for further studies on phylogenetics and conservation genetics of this species. The phylogenetic relationships of the family Geoemydidae were analyzed by maximum-likelihood (ML) and neighbor-joining (NJ) based on concatenated sequences of 13 protein-coding genes from 20 turtle species. The ML and NJ trees had homologous topologies. The results support the existing classification of the genera of Geoemydidae, that C. dentata was a sister species of C. atripons, Pyxidea nested in Cuora, and Chinemys was synonymous with Mauremys.

The complete mitochondrial genome sequence of Herzensteinia microcephalus (Cypriniformes: Cyprinidae)

Herzensteinia microcephalus (Herzenstein, 1891) is the highest naturally occurring cyprinid in the world, and inhabits rivers in the Tibetan Plateau at elevations of 4500–5200 m. Few studies on this species have been contributed. In this study, we got the mitochondrial genome sequences of H. microcephalus. The mitogenome of H. microcephalus is16,726 in length, which includes 13 protein-coding genes, 22 tRNA genes, two rRNA genes and two non-coding regions: control region (D-loop) and origin of light-strand replication (OL). The overall nucleotide base composition is 28.41% for A, 27.16% for T, 26.04% for C and 18.38% for G. This study can provide important molecular theory basis for carrying out the study on the genetics, phylogeny and adaptive evolution of Herzensteinia.

Complete mitochondrial genome of the crocodile shark Pseudocarcharias kamoharai (Lamniformes: Pseudocarchariidae)

In this study, we determined the complete mitogenome sequence of Pseudocarcharias kamoharai. The complete mitogenome of P. kamoharai is 16,694 bp in length, which contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs and 2 non-coding regions: control region (D-loop) and origin of light-strand replication (OL). Overall, base composition of mitogenome is estimated to be 32.06% for A, 23.63% for C, 13.21% for G and 31.10% for T. The complete mtDNA sequence of P. kamoharai provides a useful data for the studies on the molecular systematic phylogeography and population genetics.

Mitochondrial DNA sequence of the hybrid of Takifugu flavidus (♀) × Takifugu rubripes (♂)

The complete mitochondrial genome of the hybrid of Takifugu flavidus (♀) × Takifugu rubripes (♂) was sequenced and characterized. The total length of the mitogenome is 16,443 bp. It contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 2 non-coding regions: origin of light-strand replication (OL) and control region (D-loop). The overall nucleotide composition of the heavy strand is 30.05% A, 25.79% T, 15.07% G and 29.09% C, with an A + T content of 55.84%. Except for ND6 gene and eight tRNA genes, other genes are encoded on the heavy strand. The complete mitogenome of the hybrid of T. flavidus (♀) × T. rubripes (♂) should contribute to further studies on mitochondrial inheritance mechanism.

The complete mitochondrial genome sequence of Hemibagrus sp. (Siluriformes: Bagridae)

At present, the phylogenetic and taxonomic positions of Bagridae and Siluriformes have long been unclear. In this paper, we sequenced and annotated the complete mitogenome of Hemibagrus sp. The total length was 16,529 bp, and was typically consist of 37 genes, including 13 protein-coding genes, 2 rRNAs, 22 tRNA, a light-strand replication origin (OL) and a single large control region (CR). Except for eight tRNA and ND6 genes, all other mitochondrial genes were encoded on the heavy strand (H-strand). The gene content, organization and arrangement were identical to that of a typical bony fish. The overall base composition was 26.5%, 26.8%, 31.7% and 15.0% for T, C, A and G, respectively, with a slight bias on AT content (58.2%). This information could not only contribute to provide useful molecular data for the species identification, but also to further taxonomic and phylogenetic studies of Hemibagrus and Bagridae.

The complete mitochondrial genome sequence of Neovison vison (Carnivora: Mustelidae)

The phylogenetic and taxonomic position of the American mink Neovison vison have long been unclear. In this paper, the complete mitogenome of N. vison was sequenced and characterized. The total length was 16,594 bp and typically consists of 37 genes, including 13 protein-coding genes, 2 rRNAs, 22 tRNA, a large control region (CR) and a light-strand replication origin (OL). Gene contents, locations, and arrangements were identical to those of typical vertebrate. The overall base composition is 33.6%, 25.4%, 27.8% and 13.3% for A, C, T and G, respectively, with a moderate bias on AT content (61.4%). This result is expected to provide useful molecular data and contribute to further taxonomic and phylogenetic studies of Mustelidae and Carnivora.