The complete mitochondrial genome of Phrynocephalus guinanensis (Reptilia, Squamata, Agamidae)

Arsenic-Induced Cardiovascular Diseases and their Correlation with Mitochondrial DNA Copy Number, Deletion, and Telomere Length in Bangladeshi Population

Arsenic contamination is a global health concern, primarily through contaminated groundwater and its entry into the food chain. The association between arsenic exposure and cardiovascular diseases (CVDs) is particularly alarming due to CVDs being the leading cause of death worldwide. Arsenic exposure has also been linked to changes in telomere length, mitochondrial DNA copy number (mtDNAcn), and deletion, further increasing the risk of CVDs. We aimed to determine whether arsenic exposure alters telomere length and mtDNAcn and deletion in a total of 50 CVD patients who underwent open heart surgery hailed from known arsenic-affected and unaffected areas in Bangladesh. Amount of arsenic was determined from the collected nails and cardiac tissues. Relative telomere length and mtDNAcn and deletion were quantified by qRT-PCR. The patients from arsenic-contaminated areas had higher average arsenic deposits in their fingers and toenails (P < 0.05) and higher cardiac tissue injury scores (P < 0.05). Moreover, approximately 1.5-fold shorter telomere length (P < 0.05, r =  - 0.775), 1.2-fold decreased mtDNAcn (P < 0.05, r = - 0.797), and an 81-fold higher amount of mitochondrial DNA deletion (P < 0.05, r = 0.784) were observed in the patients who had higher arsenic deposition in their nails. Higher levels of arsenic exposure were found to be linked to shorter telomere length, decreased mtDNAcn, and increased mitochondrial DNA deletion in the patients from As-affected areas. It can also be anticipated that the correlation of arsenic exposure with telomere length, mtDNAcn, and deletion can be used as biomarkers for early diagnosis of arsenic-induced cardiovascular diseases.

Comparative Analysis of Mitochondrial Genomes in Two Subspecies of the Sunwatcher Toad-Headed Agama (Phrynocephalus helioscopus): Prevalent Intraspecific Gene Rearrangements in Phrynocephalus

Intraspecific rearrangements of mitochondrial genomes are rarely reported in reptiles, even in vertebrates. The sunwatcher toad-headed agama, Phryncoephalus helioscopus, can serve as an excellent model for investigating the dynamic mitogenome structure at intraspecific level. To date, seven subspecies of P. helioscopus are well recognized, but little is known about the mitogenomic evolution among different subspecies. In this study, complete mitogenomes of subspecies P. helioscopus varius II and P. helioscopus cameranoi were determined by next-generation sequencing, and another P. helioscopus varius I retrieved from GenBank was compiled for comparative analysis. The nucleotide composition and the codon usage are similar to those previously published from toad-headed agamas. P. helioscopus varius II and P. helioscopus cameranoi have 23 tRNA genes, including standard 22 tRNA genes and one extra tRNA-Phe (tRNA-Phe duplication). Gene order and phylogenetic analyses in the genus Phrynocephalus support prevalent intraspecific gene rearrangement in P. helioscopus and other congener species including P. erythrurus, P. vlangalii, and P. forsythii. Six different mitochondrial gene arrangements are observed in Phrynocephalus. Overall, the occurrence of rearrangements may result from multiple independent structural dynamic events. The split of the two subspecies in P. helioscopus was dated at approximately 2.34 million years ago (Ma). Two types of gene rearrangements are found in the three mitogenomes of P. helioscopus, and this intraspecific rearrangement phenomenon can be explained by the tandem duplication/random loss (TDRL) model. Post duplication, the alternative loss types can occur in 0.23–0.72 Ma, suggesting that the duplication and fixation of these rearrangements can occur quite quickly. These findings highlight the need for more mitogenomes at the population level in order to better understand the potentially rampant intraspecific mitogenomic reorganization in Phrynocephalus.

The first mitochondrial genome of Sepsis monostigma (Diptera: Sepsidae)

The sepsid fly Sepsis monostigma belongs to the genus Sepsis of Sepsidae. We sequenced and annotated the mitogenome of S. monostigma which as the first representative of genus Sepsis with nearly complete mitochondrial data. This mitogenome is 14,887bp long, which contains of 22 transfer RNA genes, 13 protein coding genes (PCGs) and 2 ribosomal RNA genes and a part of the AT control region. ML phylogenetic outcome strongly supported the monophyly of Sepsidae, and the family Sepsidae is more close to the family Heleomyzidae. It also indicated that the genus Sepsis is the sister group to Nemopoda, and the genus Archisepsis is the sister group to Microsepsis.

The complete mitochondrial genomes of Diplonevra funebris and Diplonevra peregrina (Diptera: Phoridae)

Diplonevra is one of the most important genera in the family Phoridae. This genus is mainly distributed in Palearctic region, and its species can be used to estimate the postmortem interval. In this study, we first present two mitochondrial genomes of common necrophagous species of this genus, Diplonevra funebris (Meigen, 1830) and Diplonevra peregrina (Wiedemann, 1830). Maximum-likelihood phylogenetic tree revealed that the genus Diplonevra is closely related to the genus Dohrniphora within the family Phoridae. This work expands the knowledge about the Phoridae genomes, and contributes to the further study of species identification and phylogenetics of this family.

The complete mitochondrial genomes of two scuttle flies, Megaselia spiracularis and Dohrniphora cornuta (Diptera: Phoridae)

Megaselia spiracularis and Dohrniphora cornuta were two forensically important flies in relatively sealed environments. Their mitochondrial genomes were first sequenced, annotated, and phylogenetic analyses were performed with other 8 species of the Asehiza in this study. Maximum-likelihood phylogenetic tree revealed that Phoridae is closer to Platypezidae and Lonchopteridae within Diptera. This work increases the databases of Phoridae species, and contributes to the further study of species identification and phylogenetics of this family.

Association between mitochondrial DNA copy number and cardiovascular disease: Current evidence based on a systematic review and meta-analysis

Background

Mitochondria are energy-producing structure of the cell and help to maintain redox environment. In cardiovascular disease, the number of mitochondrial DNA (mtDNA) will changes accordingly compare to normal condition. Some investigators ask whether it has a clear association between mtDNA and cardiovascular disease with its adverse events. Thus, we conduct the meta-analysis to assess the role of circulating mtDNA in evaluating cardiovascular disease.

Methods

The meta-analysis was conducted in accordance with a predetermined protocol following the recommendations of Cochrane Handbook of Systematic Reviews. We searched the Pubmed, Embase, the Cochrane Central Register of Controlled Trials and World Health Organization clinical trials registry center to identify relevant studies up to the end of October 2017. Data were analyzed using STATA. Besides, publication bias and meta-regression analysis were also conducted.

Results

We collected results from 5 articles for further analyses with 8,252 cases and 20,904 control. The normalized mtDNA copy number level is lower in cardiovascular disease (CVD) than the control groups with a pooled standard mean difference (SMD) of -0.36(95%CI,-0.65 to -0.08); The pooled odds ratio (OR) for CVD proportion associated with a 1-SD (standard deviation) decrease in mtDNA copy number level is 1.23 (95% CI,1.06–1.42); The OR for CVD patients with mtDNA copy number lower than median level is 1.88(95% CI,1.65–2.13); The OR for CVD patients with mtDNA copy number located in the lowest quartile part is 2.15(95% CI, 1.46–3.18); the OR between mtDNA copy number and the risk of sudden cardiac death (SCD) is 1.83(95% CI, 1.22–2.74).

Conclusion

Although inter-study variability, the overall performance test of mtDNA for evaluating CVD and SCD revealed that the mtDNA copy number presented the potential to be a biomarker for CVD and SCD prediction. Given that, the fewer copies of mtDNA, the higher the risk of CVD.

The complete mitochondrial genome of the lizard subspecies, Phrynocephalus vlangalii vlangalii (Reptilia, Squamata, Agamidae)

The complete mitochondrial genome was sequenced from the toad-headed lizard, Phrynocephalus vlangalii vlangalii. The overall length of mitogenome is 16,319 bp, including 22 tRNA, 13 protein coding genes, 2 rRNA genes, and 2 control regions. The gene order and content were same with the published congeneric mitogenomes, besides the small portion between tRNA-Pro and tRNA-Phe.

The complete mitochondria genome of Calliphora vomitoria (Diptera: Calliphoridae)

Calliphora vomitoria is a significant insect which belongs to the Calliphoridae family. In this study, the mitochondrial genome of C. vomitoria was completely sequenced for species identification. The entire mitogenome was 16,134 bp in length, composing of 13 protein-encoding genes, 22 transfer RNA genes and two ribosomal RNA genes, and then the array of the genes was similar to the other insects have discovered. The overall base compositions of A, G, C and T were 39.40%, 9.37%, 13.08% and 37.13% respectively. What is more, phylogenetic analyses tree indicated that entire mitochondria genome sequences of C. vomitoria had high degree of identification among the species listed in. We hope that the results from the present study will provide useful dipteran mitochondrial genomes information for the further studies on genetic structure and phylogenetic analyses of C. vomitoria in the species identifications.

Decreased Peripheral Mitochondrial DNA Copy Number is Associated with the Risk of Heart Failure and Long-term Outcomes

Mitochondrial DNA (mtDNA) copy number variation (CNV), which reflects the oxidant-induced cell damage, has been observed in a wide range of human diseases. However, whether it correlates with heart failure, which is closely related to oxidative stress, has never been elucidated before. We aimed to systematically investigate the associations between leukocyte mtDNA CNV and heart failure risk and prognosis. A total of 1700 hospitalized patients with heart failure and 1700 age- and sex-matched community population were consecutively enrolled in this observational study, as well as 1638 (96.4%) patients were followed prospectively for a median of 17 months (12-24 months). The relative mtDNA copy number of leukocyte of peripheral blood or cardiac tissue was measured in triplicate by quantitative real-time PCR method. Patients with heart failure possessed much lower relative mtDNA copy number compared with control subjects (median 0.83, interquartile range [IQR] 0.60-1.16 vs median 1.00, IQR 0.47-2.20; P < 0.001), especially for the patients with ischemic etiology (median, 0.77 for ischemic and 0.91 for non-ischemic, P < 0.001). Patients with lower mtDNA copy number exhibited 1.7 times higher risk of heart failure (odds ratio 1.71, 95% confidence interval [CI] 1.48-1.97, P < 0.001). Long-term follow-up (median of 17 months) showed that decreased mtDNA copy number was significant associated with both increased cardiovascular deaths (hazard ratio [HR] 1.58, 95% CI 1.16-2.16, P = 0.004) and cardiovascular rehospitalization (HR 1.48, 95% CI 1.21-1.82, P < 0.001). After adjusting for the conventional risk factors and medications, lower mtDNA copy numbers were still significantly associated with 50% higher cardiovascular mortality (P = 0.035). In conclusion, mtDNA copy number depletion is an independent risk factor for heart failure and predicts higher cardiovascular mortality in patients with heart failure.