Schizothorax argentatus that only distributes in the Ili River basin in Xinjiang is one of the rare and endangered species of schizothorax in China, thus has high scientific and economic values. In this study, the complete mitochondrial genome sequence of S. argenteus with a length of 16 580 bp was obtained by high-throughput sequencing. The gene compositions and arrangement were similar to those of typical vertebrates. It contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a non-coding region (D-loop). The nucleotide compositions were A (30.25%), G (17.28%), C (27.20%), and T (25.27%), respectively, showing obvious AT bias and anti-G bias. Among the tRNA genes, only tRNA-Ser^(GCU) could not form a typical cloverleaf structure due to the lack of dihydrouracil arm. The AT-skew and GC-skew values of the ND6 gene were fluctuating the most, suggesting that the gene may experience different selection and mutation pressures from other genes. The mitochondrial control region of S. argenteus contained three different domains, i.e., termination sequence region (ETAS), central conserved region (CSB-F, CSB-E, CSB-D, and CSB-B), and conserved sequence region (CSB1, CSB2, and CSB3). The conserved sequence fragment TT (AT) nGTG, which was ubiquitous in Cypriniformes, was identified at about 50 bp downstream CSB3. Phylogenetic relationships based on the complete mitochondrial genome sequence of 28 Schizothorax species showed that S. argenteus had differentiated earlier and had a distant relationship with other species, which may be closely related to the geographical location and the hydrological environment where it lives.
Animals ; Genome, Mitochondrial/genetics* ; Phylogeny ; Sequence Analysis, DNA ; Cyprinidae/genetics* ; RNA, Transfer/genetics* ; DNA, Mitochondrial/genetics* ; Genes, Mitochondrial

Mitochondrial DNA (mtDNA) mutations result in a variety of genetic diseases. As an emerging therapeutic method, mtDNA editing technology recognizes targets more based on the protein and less on the nucleic acid. Although the protein recognition type mtDNA editing technology represented by zinc finger nuclease technology, transcription activator like effector nuclease technology and base editing technology has made some progress, the disadvantages of complex recognition sequence design hinder further popularization. Gene editing based on nucleic acid recognition by the CRISPR system shows superiority due to the simple structure, easy design and modification. However, the lack of effective means to deliver nucleic acids into mitochondria limits application in the field of mtDNA editing. With the advances in the study of endogenous and exogenous import pathways and the deepening understanding of DNA repair mechanisms, growing evidence shows the feasibility of nucleic acid delivery and the broad application prospects of nucleic acid recognition type mtDNA editing technology. Based on the classification of recognition elements, this article summarizes the current principles and development of mitochondrial gene editing technology, and discusses its application prospects.
Genes, Mitochondrial ; Gene Editing ; Mitochondria/genetics* ; DNA, Mitochondrial/genetics* ; Nucleic Acids ; Technology

As conserved enzymes with important functions, aminoacyl-tRNA synthetase are expressed ubiquitously in cells. These include cytoplasmic aminoacyl-tRNA synthetase, mitochondrial aminoacyl-tRNA synthetase and bifunctional aminoacyl-tRNA synthetase. Mitochondrial aminoacyl-tRNA synthetases catalyze the binding of amino acids with its corresponding tRNA in the mitochondria and participate in the translation of 13 subunits of oxidative phosphorylation enzyme complexes encoded by the mitochondrial genome. Mutations in genes encoding mitochondrial aminoacyl-tRNA synthase may cause a variety of genetic disorders. This review has summarized the clinical characteristics, molecular pathogenesis and treatment of genetic diseases caused by mutations of such genes.
Humans ; RNA, Transfer, Amino Acyl ; Genes, Mitochondrial ; Amino Acyl-tRNA Synthetases/genetics* ; Genome, Mitochondrial ; Mitochondria/genetics*

OBJECTIVE: To explore the genetic basis for a child with Leigh syndrome. METHODS: Clinical features and laboratory test of the patient were analyzed. Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) of the mitochondrial genome were carried out. Next generation sequencing (NGS) was used to capture and sequence nuclear genes related to mitochondrial structure and function. RESULTS: The child presented with developmental delay, unsteady gait, falling episodes, bilateral upper extremity tremor, muscle hypertonia, convulsions, and mouth angle asymmetry. Serum lactic acid was significantly increased. Cranial MRI showed abnormal signal in bilateral cerebellar hemispheres, bilateral basal ganglia, left thalamus, and corona radiata. Her mother and brother did not show any anomalies. Sanger sequencing revealed the child, her mother and brother all carried the MT-ND3 m.10191 T>C mutation, with heterogeneous rates respectively being 74.34%, 9.73%, and 6.28%. MLPA revealed heterogeneity of (MT-ND6, MTCYB-390nt)] deletion in all three individuals. No significant mutation was found by NGS sequencing of the children, their parents and brother. CONCLUSION Leigh syndrome can be caused by the simultaneous existence of multiple mitochondrial genes, and multiple mutations may play a synergic role in the occurrence of the disease.
Child ; DNA, Mitochondrial ; Female ; Genes, Mitochondrial ; High-Throughput Nucleotide Sequencing ; Humans ; Leigh Disease ; genetics ; Male ; Mutation

OBJECTIVE: To detect the 278 bp region of gene of the cytochrome oxidase subunit I (COI) in mitochondral DNA (mtDNA) of sarcosaphagous flies, identify the species of sarcosaphagous flies, and provide reference for forensic application. METHODS: Samples were collected in Baotou and Chifeng of Inner Mongolia, Tianjin, Nanning, Fuzhou, Linyi of Shandong, Shijiazhuang, Yinchuan, Lanzhou, Huairou of Beijing, Xinxiang and Nanyang of Henan, Datong of Shanxi, Wuhu of Anhui, Quzhou of Zhejiang, Changsha, Zhuzhou and Yongzhou of Hunan. A total of 38 flies were randomly collected from rabbits, dogs and pigs which were set outdoors, then the flies' mitochondrial DNA (mtDNA) were extracted by the improved small insects DNA homogenate method. Amplification was conducted by Perkin-Elmer 9600 thermal cycler, then vertical non-denaturing 7% polyacrylamide gelectrophoresis. PCR products were purified using the nucleic acid purification kit. Sequences of both strands were obtained by direct sequence of the double-stranded PCR product using one of the PCR primers and the ABI PRISM big dye terminator cycle sequencing dit. Sequence reactions were electrophorsed on ABI Model 3730 DNA Sequencers. A UPGMA tree was contrasted using the maximum composite likelihood method in MEGA4. RESULTS: The 38 sarcosaphagous flies belonged to 3 families(Muscidae, Calliphoridae, and Sarcophagidae), 10 genuses (Musca Linnaeus, Hydrotaea Robineau-Desvoidy, Aldrichina Townsend, Hemipyrellia Townsend, Achoetandrus Bezzi, Protophormia Townsend, Chrysomya Robineau-Desvoidy, Lucilia Robineau-Desvoidy, Helicophagella Enderlein, and Boettcherisca Rohdendorf), and 12 species [Musca domestica (Linnaeus), Hydrotaea (Ophyra) capensis (Wiedemann), Lucilia caesar (Linnaeus), Lucilia illustris (Meigen), Aldrichina graham (Aldrich), Hemipyrellia ligurriens, Achoetandrus (Chrysomya) rufifacies (Macquary), Protophormia terraenovae (Robineau-Desvoidy), Chrysomya megacephala (Fabricius), Lucilia sericata (Meigen), Helicophagella melanura (Meigen), and Boettcherisca peregrine (Robineau-Desvoidy)]. CONCLUSION The genus of the sarcosaphagous flies can be identified by 278 bp gene sequence analysis of CO I in mtDNA. This method is rapid, convenient and precise.
Animals ; China ; DNA, Mitochondrial ; genetics ; Electron Transport Complex IV ; classification ; genetics ; Forensic Medicine ; Genes, Insect ; Genes, Mitochondrial ; Larva ; genetics ; Phylogeny ; Sarcophagidae ; classification ; genetics ; Sequence Analysis, DNA ; Species Specificity

OBJECTIVETo classify Pueraria lobata originated from different geographical regions based on ITS,psbK-psbI and trnH-psbA information.

METHODTwenty-four samples of P. lobata were collected from northeast China, north China, central China and northwest China. DNA extraction, PCR, sequence and genotypes/haplotypes analysis were performed .

RESULTITS1, 5.8S and ITS2 varied only 1 bp respectively, psbK-psbI 2 bps; trnH-psbA varied 1 bp and 10 bp deletion.

CONCLUSIONBased on the variation of ITS,psbK-psbI and trnH-psbA, 4 genotypes and 2 haplotypes were identified, respectively.

Cloning of flanking sequences of double-copy gene is a challenge in molecular biology. We developed a method to solve this problem by combining an optimized inverse PCR (iPCR) with TAIL-PCR. First, Southern blotting analysis was used to determine a proper restriction enzyme that could obtain proper-length restriction fragments that contained the target gene. Then optimized iPCR was performed to amplify the restriction fragments that contained the separated copies of the gene. Based on the obtained sequences, TAIL-PCR was performed to amplify further flanking regions of the gene. With this method, we obtained all of the EcoR I restriction fragments (2.2-5.1 kb) and Hind III restriction fragments (8.5-11.7 kb) of mitochondrial atpA gene in cytoplasmic male sterile (CMS) line and maintainer line of Upland cotton. The results showed that this method was an efficient approach to clone flanking sequences of double-copy gene.
Chromosome Walking ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Genes, Mitochondrial ; Genes, Plant ; genetics ; Gossypium ; genetics ; Plant Proteins ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Terminal Repeat Sequences

Mitochondrial genomes have been extensively studied for phylogenetic purposes and to investigate intra- and interspecific genetic variations. In recent years, numerous groups have undertaken sequencing of platyhelminth mitochondrial genomes. Haplorchis taichui (family Heterophyidae) is a trematode that infects humans and animals mainly in Asia, including the Mekong River basin. We sequenced and determined the organization of the complete mitochondrial genome of H. taichui. The mitochondrial genome is 15,130 bp long, containing 12 protein-coding genes, 2 ribosomal RNAs (rRNAs, a small and a large subunit), and 22 transfer RNAs (tRNAs). Like other trematodes, it does not encode the atp8 gene. All genes are transcribed from the same strand. The ATG initiation codon is used for 9 protein-coding genes, and GTG for the remaining 3 (nad1, nad4, and nad5). The mitochondrial genome of H. taichui has a single long non-coding region between trnE and trnG. H. taichui has evolved as being more closely related to Opisthorchiidae than other trematode groups with maximal support in the phylogenetic analysis. Our results could provide a resource for the comparative mitochondrial genome analysis of trematodes, and may yield genetic markers for molecular epidemiological investigations into intestinal flukes.
Animals ; Asia ; Codon, Initiator ; DNA, Mitochondrial/chemistry/genetics ; Gene Order ; Genes, Helminth ; *Genome, Mitochondrial ; Heterophyidae/*genetics/isolation & purification ; Humans ; Molecular Sequence Data ; Sequence Analysis, DNA

We compared patterns of intraspecific polymorphism of two markers with contrasting modes of evolution, nuclear ribosomal DNA (rDNA) and mitochondrial DNA (mtDNA), in the lung fluke, diploid and triploid Paragonimus westermani from three geographical regions of Korea. The genetic distances between three populations of Korean diploid and triploid P. westermani showed no significant difference in the nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (mtCOI) and ribosomaal second internal transcribed spacer (ITS2) genes. A highly resolved strict-consensus tree was obtained that illustrated phylogenetically useful information of the ITS2 and mtCOI sequences from diploid and triploid P. westermani.
Animals ; DNA, Mitochondrial/*genetics ; DNA, Ribosomal Spacer/*genetics ; *Diploidy ; Electron Transport Complex IV/*genetics ; Evolution, Molecular ; Genes, Helminth/genetics ; Korea ; Paragonimus/*genetics ; *Phylogeny ; *Polyploidy

Species identification of sarcosaphagous insects is one of the important steps in forensic research based on the knowledge of entomology. Recent studies reveal that the application of molecular biology, especially the mtDNA sequences analysis, works well in the species identification of sarcosaphagous insects. The molecular biology characteristics, structures, polymorphism of mtDNA of sarcosaphagous insects, and the recent studies in species identification of sarcosaphagous insects are reviewed in this article.
Amino Acid Sequence ; Animals ; Base Sequence ; DNA, Mitochondrial/genetics* ; Diptera/genetics* ; Electron Transport Complex IV/genetics* ; Entomology ; Forensic Medicine/methods* ; Genes, Mitochondrial/genetics* ; Insecta/genetics* ; Polymerase Chain Reaction ; Polymorphism, Genetic ; RNA, Ribosomal/genetics* ; Sequence Analysis, DNA ; Species Specificity