Mitochondrial Dna最新文献

Many species of catfish are important resources for human consumption, for sport fishing and for use in aquarium industry. In the Philippines, some species are cultivated and some are caught in the wild for food and a few introduced species have become invasive. In this study, DNA barcoding using the mitochondrial cytochrome c oxidase I (COI) gene was done on commercially and economically important Philippine catfishes. A total of 75 specimens belonging to 11 species and 5 families were DNA barcoded. The genetic distances were computed and Neighbor-Joining (NJ) trees were constructed based on the Kimura 2-Parameter (K2P) method. The average K2P distances within species, genus, family and order were 0.2, 8.2, 12.7 and 21.9%, respectively. COI sequences clustered according to their species designation for 7 of the 11 catfishes. DNA barcoding was not able to discriminate between Arius dispar and A. manillensis and between Pterygoplichthys disjunctivus and P. pardalis. The morphological characters that are used to distinguish between these species do not complement molecular identification through DNA barcoding. DNA barcoding also showed that Clarias batrachus from the Philippines is different from the species found in India and Thailand, which supports earlier suggestions based on morphology that those found in India should be designated as C. magur and those in mainland Southeast Asia as C. aff. batrachus "Indochina". This study has shown that DNA barcoding can be used for species delineation and for tagging some species for further taxonomic investigation, which has implications on proper management and conservation strategies.

Mitochondrial DNA (mtDNA) variation may play an important role in the pathogenesis of type 2 diabetes (T2Ds). In this study, we aimed to explore whether mtDNA variants contribute to the susceptibility to T2Ds in a Tunisian population. The hypervariable region 1 (HVS1) of the mtDNA of 64 T2Ds patients and 77 healthy controls was amplified and sequenced. Statistical analysis was performed using the STATA program. Analysis of the total screened variants (N = 88) from the HVS1 region showed no significant difference in the distribution of all polymorphisms between T2Ds and controls, except for the variant G16390A which was more frequent in T2Ds (15.9%) than in controls (5.4%) (p = 0.04). The association of G16390A was not detected after multivariate regression analysis. Similarly, analysis of the distribution of mitochondrial haplogroups within our dataset showed 18 distinct major haplogroups with no significant difference between T2Ds and controls. Except, the weakly association found for the G16390A variant, our results showed that none of the tested polymorphisms from the HVS1 region have a major role in T2Ds pathogenesis in the studied Tunisian population even when taking into account the population stratification.

Larval dispersal may have an important effect on genetic structure of benthic species. However, different species may choose different larval dispersal strategy. To examine the population genetic structure and larval dispersal strategy of portunid crab Charybdis bimaculata, a 658 base pair (bp) fragment of mtDNA COI gene was sequenced in this species. In total, 67 individuals were collected from 5 locations in Yellow Sea and East China, and 24 haplotypes were obtained. Mean haplotype diversity and nucleotide diversity for the five populations ranged from 0.2000 ± 0.1541 (Zhoushan) to 0.8333 ± 0.1265 (Nanji island), and from 0.0003 ± 0.0005 (Zhoushan) to 0.0026 ± 0.0019 (Nanji island). Analysis of molecular variance and pairwise FST revealed no significant differentiation between the Yellow Sea and the East China Sea in C. bimaculata, supporting high larval dispersal ability in this species, rejecting larval retention. Mismatch distribution revealed that C. bimaculata had undergone population expansion. Larval drift in the ocean currents, and recent range expansion could be the reasons for little genetic structure in the studied area.

To examine whether certain mitochondrial DNA (mtDNA) haplogroups and/or alterations affect susceptibility to aggressive periodontitis (AgP), we analyzed the mtDNA D-Loop region in a Han Chinese population. The mtDNA haplogroups were analyzed in 58 patients with AgP and 50 periodontally healthy controls. The frequency of haplogroups A in AgP group was significantly higher than that in the control group (p=0.007). Furthermore, the frequency of haplogroup D was higher in the control group than that in AgP group (p=0.007). The frequencies of D-Loop polymorphisms m.16126T>C, m.16290C>T and m.152 T> C were significantly higher in patients with AgP compared with controls (p=0.029, 0.014 and 0.022, respectively). Additionally, the frequencies of three other D-Loop polymorphisms, m.16223C>T m.489 T>C and m.515CA deletion (del) were significantly lower in patients with AgP compared with controls (p=0.042, 0.003 and 0.026, respectively). Our study showed for the first time, an association between AgP and mtDNA haplogroups. Haplogroups A was implicated as a risk factor for AgP, while haplogroups D exhibited a protective effect in this disease. These observations may provide a new perspective on the study of the pathogenesis of periodontitis.

The complete mitochondrial genome sequence of the Feirana taihangnica (Anura: Dicroglossidae) was determined. It is a circular molecule of 17,412 bp in length, containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a control region. The tRNA(Thr) gene located in the LTPF tRNA gene cluster typically found in other anurans is absent from the F. taihangnica mtDNA and a tandem duplication of tRNA(Met) gene is observed. The A+T content of the overall base compositon of H-strand is 57.2% and the length of control region is 1972 bp with 61.8% A+T content.

This research aimed at exploring sequence variability in four mitochondrial (mt) genes, namely, cytochrome c oxidase subunit 1 (cox1), cytochrome b (cytb) and NADH dehydrogenase subunits 1 and 5 (nad1 and nad5), among pinworm Aspicularis tetraptera isolates from laboratory mice in four different provinces, China. A part of the cox1 (pcox1), cytb (pcytb), nad1 and nad5 genes (pnad1 and pnad5) were amplified separately from individual pinworms by polymerase chain reaction (PCR) and sequenced to determine sequence variations and examine their phylogenetic relationships. Herein, the intra-specific sequence variations within A. tetraptera were 0-0.5% for pcox1, 0-1.4% for pcytb, 0-1.8% for pnad1 and 0-1.7% for pnad5, respectively. In contrast, the inter-specific sequence differences among members of the Oxyuridae were significantly higher, being 13.7-17.0% for pcox1, 24.5-34.7% for pcytb, 26.6-29.6% for pnad1 and 24.4-25.5% for pnad5, respectively. Three methods, namely, Bayesian inference (BI), maximum likelihood (ML) and maximum parsimony (MP), were used for phylogenetic analyses based on the combined sequences of the four mt gene sequences, and the results indicated that all A. tetraptera samples form monophyletic groups, but samples from the same geographical origin did not always cluster together. This study demonstrated the existence of low-level intra-specific variation in four mtDNA sequences among A. tetraptera isolates from laboratory mice in different geographic regions in China, indicating no obvious geographical distinction among A. tetraptera isolates in China. These findings have important implications for studying systematics, molecular epidemiology and population genetics of A. tetraptera.

The Jacobin is a breed of fancy pigeon developed over many years of selective breeding that originated in Asia. In the present work, we report the complete mitochondrial genome sequence of Jacobin pigeon for the first time. The total length of the mitogenome was 17,245 bp with the base composition of 30.18% for A, 23.98% for T, 31.88% for C, and 13.96% for G and an A-T (54.17 %)-rich feature was detected. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region. The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of Jacobin pigeon would serve as an important data set of the germplasm resources for further study.

In this work, we report the complete mitochondrial genome sequence of Sus cebifrons (Visayan warty pig). The total length of the mitogenome was 16,475 bp, and its overall base composition was estimated to be 35.0% for A, 25.8% for T, 26.2% for C and 13.0% for G, indicating an A-T (60.8%)-rich feature in Sus cebifrons mitogenome. It contained the typical structure of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a noncoding control region (D-loop region). The arrangement of these genes was the same as that found in other pigs. The complete mitochondrial genome sequence of the Sus cebifrons would provide new genetic resources for pig domestication study.

Echinococcus granulosus is the etiological agent of cystic echinococcosis, a major zoonotic disease of both humans and animals. In this study, we assessed genetic variability and genetic structure of E. granulosus in the Tibet plateau, using the complete mitochondrial 16 S ribosomal RNA gene for the first time. We collected and sequenced 62 isolates of E. granulosus from 3 populations in the Tibet plateau. A BLAST analysis indicated that 61 isolates belonged to E. granulosus sensu stricto (genotypes G1-G3), while one isolate belonged to E. canadensis (genotype G6). We detected 16 haplotypes with a haplotype network revealing a star-like expansion, with the most common haplotype occupying the center of the network. Haplotype diversity and nucleotide diversity were low, while negative values were observed for Tajima's D and Fu's Fs. AMOVA results and Fst values revealed that the three geographic populations were not genetically differentiated. Our results suggest that a population bottleneck or population expansion has occurred in the past, and that this explains the low genetic variability of E. granulosus in the Tibet Plateau.

The complete mitochondrial genome of the perlid stonefly Dinocras cephalotes (Curtis, 1827) was sequenced using a combined 454 and Sanger sequencing approach using the known sequence of Pteronarcys princeps Banks, 1907 (Pteronarcyidae), to identify homologous 454 reads. The genome is 15,666 bp in length and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region. Gene order resembles that of basal arthropods. The base composition of the genome is A (33.5%), T (29.0%), C (24.4%) and G (13.1%). This is the second published mitogenome for the order Plecoptera and will be useful in future phylogenetic analysis.