Remarkable mitochondrial genome heterogeneity in Meniocus linifolius (Brassicaceae).

KEY MESSAGE: Detailed analyses of 16 genomes identified a remarkable acceleration of mutation rate, hence mitochondrial sequence and structural heterogeneity, in Meniocus linifolius (Brassicaceae). The powerhouse, mitochondria, in plants feature high levels of structural variation, while the encoded genes are normally conserved. However, the substitution rates and spectra of mitochondria DNA within the Brassicaceae, a family with substantial scientific and economic importance, have not been adequately deciphered. Here, by analyzing three newly assembled and 13 known mitochondrial genomes (mitogenomes), we report the highly variable genome structure and mutation rates in Brassicaceae. The genome sizes and GC contents are 196,604 bp and 46.83%, 288,122 bp and 44.79%, and 287,054 bp and 44.93%, for Meniocus linifolius (Mli), Crucihimalaya lasiocarpa (Cla), and Lepidium sativum (Lsa), respectively. In total, 29, 33, and 34 protein-coding genes (PCGs) and 14, 18, and 18 tRNAs are annotated for Mli, Cla, and Lsa, respectively, while all mitogenomes contain one complete circular molecule with three rRNAs and abundant RNA editing sites. The Mli mitogenome features four conformations likely mediated by the two pairs of long repeats, while at the same time seems to have an unusual evolutionary history due to higher GC content, loss of more genes and sequences, but having more repeats and plastid DNA insertions. Corroborating with these, an ambiguous phylogenetic position with long branch length and elevated synonymous substitution rate in nearly all PCGs are observed for Mli. Taken together, our results reveal a high level of mitogenome heterogeneity at the family level and provide valuable resources for further understanding the evolutionary pattern of organelle genomes in Brassicaceae.

Sequencing and analysis of the complete mitochondrial genomes of Toona sinensis and Toona ciliata reveal evolutionary features of Toona.

BACKGROUND: Toona is a critical genus in the Meliaceae, and the plants of this group are an asset for both restorative and restorative purposes, the most flexible of which are Toona sinensis and Toona ciliata. To concentrate on the advancement of mitochondrial(Mt) genome variety in T.sinensis and T.ciliata, the Mt genomes of the two species were sequenced in high throughput independently, after de novo assembly and annotation to construct a Mt genome map for comparison in genome structure. Find their repetitive sequences and analyze them in comparison with the chloroplast genome, along with Maximum-likelihood(ML) phylogenetic analysis with 16 other relatives. RESULTS: (1) T. sinensis and T.ciliata are both circular structures with lengths of 683482 bp and 68300 bp, respectively. They share a high degree of similarity in encoding genes and have AT preferences. All of them have the largest Phe concentration and are the most frequently used codons. (2) Both of their Mt genome are highly preserved in terms of structural and functional genes, while the main variability is reflected in the length of tRNA, the number of genes, and the value of RSCU. (3) T. siniensis and T. ciliata were detected to have 94 and 87 SSRs, respectively, of which mononucleotides accounted for the absolute proportion. Besides, the vast majority of their SSRs were found to be poly-A or poly-T. (4)10 and 11 migrating fragments were identified in the comparison with the chloroplast genome, respectively. (5) In the ML evolutionary tree, T.sinensis and T.ciliata clustered individually into a small branch with 100% support, reflecting two species of Toona are very similarly related to each other. CONCLUSIONS: This research provides a basis for the exploitation of T.sinensis and T.ciliata in terms of medicinal, edible, and timber resources to avoid confusion; at the same time, it can explore the evolutionary relationship between the Toona and related species, which does not only have an important practical value, but also provides a theoretical basis for future hybrid breeding of forest trees, molecular markers, and evolutionary aspects of plants, which has great scientific significance.

Mitochondria transfer and transplantation in human health and diseases.

Mitochondria are dynamic organelles responsible for energy production and cell metabolism. Disorders in mitochondrial function impair tissue integrity and have been implicated in multiple human diseases. Rather than constrained in host cells, mitochondria were recently found to actively travel between cells through nanotubes or extracellular vesicles. Mitochondria transportation represents a key mechanism of intercellular communication implicated in metabolic homeostasis, immune response, and stress signaling. Here we reviewed recent progress in mitochondria transfer under physiological and pathological conditions. Specifically, tumor cells imported mitochondria from adjacent cells in the microenvironment which potentially modulated cancer progression. Intercellular mitochondria trafficking also inspired therapeutic intervention of human diseases with mitochondria transplantation. Artificial mitochondria, generated through mitochondria genome engineering or mitochondria-nucleus hybridization, further advanced our understanding of mitochondrial biology and its therapeutic potential. Innovative tools and animal models of mitochondria transplantation will assist the development of new therapies for mitochondrial dysfunction-related diseases.

Characterization of the complete mitochondrial genome of Takifugu pseudommus (Actinopterygii, Tetraodontidae).

The complete mitochondrial genome of Takifugu pseudommus was reported in the present study. It was 16,448 bp in length and consisted of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a non-coding control region. The nucleotide content of this genome was 29.91% for A, 29.09% for C, 15.20% for G, and 25.80% for T. The phylogenetic tree, constructed with complete mitochondrial genome, suggested T. pseudommus was closely related with T. chinensis, T. flavidus, and T. rubripes among Tetraodontidae species. This study could provide an important dataset for genetic diversity and species identification among the genus Takifugu.

Complete mitochondrial DNA sequence of Norwegian skates (Raja brachyuran Lafont, 1871) imported to Korea.

In this study, the complete mitochondrial genome of Norwegian skates imported to Korea was sequenced with a circular molecule of 17,121 bp, which consisted of 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 22 transfer RNA genes, and a control region (D-loop). And among these sequences, 193 bp sequence in the D-loop of the genus Raja suggested the possibility of being used as a genetic marker for classification of Raja and Dipturus species. The BI phylogenetic tree by using the nucleotide sequences of 13 PCGs from 15 available mitogenomes of family Rajidae confirmed also that Norwegian skates imported to Korea form a group with Raja brachyura species with high branch value, and that this was a species of Raja brachyura. As above, these results would be expected to provide for the further understanding on the phylogenetic relationship, taxonomic classification and phylogeography of the family Rajidae.

The complete mitochondrial genome of Eaton's skate, Bathyraja eatonii (Rajiformes, Arhynchobatidae).

The complete mitochondrial genome of Eaton's skate Bathyraja eatonii was studied using the long-read technology, PacBio Sequel System. The complete mitochondrial genome form of B. eatonii was 16,698 bp and it's comprised of 13 protein-coding genes, 22 tRNA and 2 rRNA. The base composition of B. eatonii is analyzed 31.94% for A, 33.94% for T, 13.49% for G, 20.64% for C, the result of GC content was 33.94%. Phylogenetic analysis showed that B. eatonii was closely related to Bathyraja meridionalis in Arhynchobatidae family, and this first mitochondrial genome of Antarctic skate would provide fundamental information to the evolutional relationship of Antarctic fishes.

The complete mitochondrial genome and phylogenetic analysis of Batillaria zonalis (Gastropoda: Batillariidae).

We determined the complete mitochondrial genome of Batillaria zonalis. The B. zonalis mitochondrial genome is 15748 bp in length, comprising 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The nucleotide composition for B. zonalis is 17.71% of C, 16.74% of G, 34.99% of T, and 30.3% of A. In 13 protein-coding genes, all genes start with ATG. For the stop codon, the cox2 gene stops with TTC, the cytb, nad1, nad2 genes stop with TAG, the other nine genes are with TAA. Of these 37 genes identified, nine protein-coding genes and six transfer RNA genes are encoded on the heavy strand and the other genes on the light strand. The phylogenetic tree was constructed based on 13 protein-coding genes of the B. zonalis and other 19 Gastropoda species, Sepia latimanus as outgroup using the Neighbour-joining method. The result showed that B. zonalis is most closely related to the Tylomelania sarasinorum in Cerithioidea. We believe that this result will be helpful for the study of population genetic and phylogenetic analysis of the family Batillariidae.

The complete mitochondrial genome and phylogenetic analysis of Omphalius rusticus (Gastropoda, Tegulidae).

The complete mitochondrial genome of the Omphalius rusticus has been determined. The complete genome is 18,067 bp and contained 13 protein-coding genes, two rRNA genes and 22 tRNA genes. The overall base composition is 33.48% (A), 33.52% (T), 15.58% (G) and 17.42% (C). The all start codon for 13 protein-coding genes is ATG and the most common termination codon is TAA. The phylogenetic tree showed that O. rusticus is most closely related to the Tectus pyramis. We suggest that this result will further supplement the genome information in mitochondria of the family Tegulidae and facilitate the study on population genetics.

Complete mitochondrial genome of Halocynthia hilgendorfi ritteri (Pyuridae) from Korea.

Halocynthia hilgendorfi ritteri is an ascidian distributed on the coast of Geoje Island in Korea and found on rocks. The mitochondrial genome of Halocynthia hilgendorfi ritteri consists of 15,181 bp with 13 protein-coding genes, 2 ribosomal RNAs, 23 transfer RNA genes. The overall base composition of the complete genome is 22.94% A, 43.32% T, 25.72% G, and 8.02% C, with a high A + T content of 66.26%.

The complete mitochondria genome of Sipalus gigas (Coleoptera: Curculionidae).

Sipalus gigas is the main pine-hole borer of Pinus. The length of the complete mitochondria genome of S. gigas was 17,120 bp with 33.6% GC content, there were 35 genes including 13 protein-coding genes (CDS), 20 transfer RNA genes (tRNAs), and two ribosomal RNA genes (rRNAs). This study provides useful genetic information for subsequent studying the prevention of S. gigas.

Characterization of the complete mitochondrial DNA sequence of the Lagocephalus gloveri (Tetraodontidae, Tetraodontiformes).

The complete mitochondrial genome of Lagocephalus gloveri is reported in the present study, which is 16,446 bp in length. It consists of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a non-coding control region. The overall base composition of the genome is 27.58% for A, 25.07% for T, 30.83% for C and 16.52% for G. The phylogenetic tree, which is based on 12 protein coding gene sequences, suggested that L. gloveri was closest to L. lagocephalus. This study could give impetus to studies focused on population structure and molecular evolution of L. gloveri.

Molecular typing of Cyclospora cayetanensis in produce and clinical samples using targeted enrichment of complete mitochondrial genomes and next-generation sequencing.

BACKGROUND: Outbreaks of cyclosporiasis, a diarrheal illness caused by Cyclospora cayetanensis, have been a public health issue in the USA since the mid 1990's. In 2018, 2299 domestically acquired cases of cyclosporiasis were reported in the USA as a result of multiple large outbreaks linked to different fresh produce commodities. Outbreak investigations are hindered by the absence of standardized molecular epidemiological tools for C. cayetanensis. For other apicomplexan coccidian parasites, multicopy organellar DNA such as mitochondrial genomes have been used for detection and molecular typing. METHODS: We developed a workflow to obtain complete mitochondrial genome sequences from cilantro samples and clinical samples for typing of C. cayetanensis isolates. The 6.3 kb long C. cayetanensis mitochondrial genome was amplified by PCR in four overlapping amplicons from genomic DNA extracted from cilantro, seeded with oocysts, and from stool samples positive for C. cayetanensis by diagnostic methods. DNA sequence libraries of pooled amplicons were prepared and sequenced via next-generation sequencing (NGS). Sequence reads were assembled using a custom bioinformatics pipeline. RESULTS: This approach allowed us to sequence complete mitochondrial genomes from the samples studied. Sequence alterations, such as single nucleotide polymorphism (SNP) profiles and insertion and deletions (InDels), in mitochondrial genomes of 24 stool samples from patients with cyclosporiasis diagnosed in 2014, exhibited discriminatory power. The cluster dendrogram that was created based on distance matrices of the complete mitochondrial genome sequences, indicated distinct strain-level diversity among the 2014 C. cayetanensis outbreak isolates analyzed in this study. CONCLUSIONS: Our results suggest that genomic analyses of mitochondrial genome sequences may help to link outbreak cases to the source.

The complete mitochondrial genome of Epicauta ruficeps (Coleoptera: Meloidae).

Epicauta ruficeps is widely distributed in China and some countries in Southeast Asia, and plays an important role in medicine and biological control. The complete mitochondria genome of E. ruficeps was 15,813 bp in length, with 37 genes, including 13 PCGs, 22 tRNA genes (tRNAs), and two rRNA genes (rRNAs). The positions and sequences of genes were consistent with those of known Meloidae species. The nucleotide composition was highly A + T biased, accounting for ∼65% of the whole mitogenome. The complete mitogenome of E. ruficeps would help understand Meloidae evolution.

The complete mitochondrial genome of Macrourus whitsoni (Gadiformes, Macrouridae).

The complete mitochondrial genome of Macrourus witsoni was determined in this study by the Long-read Technology, such as PacBio Sequel System. The Long-read Technology, which can sequence continuously the whole vertebrate mitochondrial genome, allows more accurate genomes to be completed. The circular form of its mitochondrial genome was 16,714bp, which contained 13 protein-coding genes, 22 tRNA, and 2 rRNA. The gene orders of M.witsoni was identical to that of the other species of Macrouridae family. Phylogenetic analysis indicated M. witsoni was mostly close to C.kishinouyei in the Macrouridae family.

The complete mitochondrial genome and phylogenetic analysis of Batillaria cumingi (Gastropoda: Batillariidae).

We determined the complete mitochondrial genome of Batillaria cumingi. The B. cumingi mitochondrial genome is 16,100 bp in length, comprising 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The nucleotide composition for B. cumingi is 17.5% of C, 16.88% of G, 35.3% of T, and 30.31% of A. In 13 protein-coding genes, all genes start with ATG. For the stop codon, the cox2 gene stops with TTC, the cytb, nad1, and nad2 genes stop with TAG, and the other nine genes are with TAA. Of these 37 genes identified, nine protein-coding genes and six transfer RNA genes are encoded on the heavy strand and the other genes on the light strand. The phylogenetic tree was constructed based on 13 protein-coding genes of the B. cumingi and other 19 Gastropoda species, Sepia latimanus as outgroup using the Neighbour-joining method. The tree showed that the B. cumingi is closely related to the Semisulcospira coreana in Cerithioidea. We believe that this result will be helpful for the study of population genetic and phylogenetic analysis of the family Batillariidae.

The complete mitochondrial genome of Patagonian moray cod, Muraenolepis orangiensis Vaillant, 1888 (Gadiformes, Muraenolepididae).

The full-length mitochondrial genome of Muraenolepis orangiensis (Vaillant, 1888) was studied using PacBio platform and it is first report in a Muraenolepididae family. The circular form of mitochondria genome is 16,833 bp including 13 protein-coding genes, two rRNA, and 22 tRNA. Start codon of 13 protein-coding genes was only ATG but three types of stop codons (TAA, T(AA), and TAG) were detected. To evaluate evolutionary position of M. orangiensis, the phylogenetic tree with other 13 Antarctic fishes belonged to five families were showed that M. orangiensis is unique cluster as a Muraenolepididae family and this study would provide fundamental data to understand the evolutionary relationship of fishes founded in Antarctic area.

Characterization of the complete mitochondrial DNA sequence of the Lagocephalus guentheri (Tetraodontidae, Tetraodontiformes).

The complete mitochondrial genome of Lagocephalus guentheri was reported in the present study, which was 16,461 bp in length. It consists of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a non-coding control region. The overall base composition of the genome is 27.54% for A, 24.80% for T, 31.23% for C and 16.43% for G. The phylogenetic tree, which is based on 12 protein-coding gene sequences, suggested that L. guentheri was closest to L. spadiceus. This study could give impetus to studies focused on population structure and molecular evolution of L. guentheri.

WHOLE SEQUENCING OF THE MITOCHONDRIAL GENOME OF BREAST CANCER TISSUE IN MEXICAN-MESTIZO POSTMENOPAUSAL WOMEN WITH DIFFERENT BODY MASS INDEX.

BACKGROUND: Mitochondrial and oxidative stress has been related to obesity and breast cancer being this cancer more frequent and more aggressive in postmenopausal women with obesity. OBJECTIVE: The objective of this study was to investigate whether Mexican-Mestizo postmenopausal women with breast cancer and obesity present different somatic mutations in the mitochondrial DNA (mtDNA) when compared to women with normal body mass index (BMI). SUBJECTS AND METHODS: We included six Mexican-Mestizo postmenopausal women bearing breast cancer and who underwent mastectomy or breast-conserving surgery. BMI was determined in each case. Patients' genomic DNA was isolated from blood leukocytes and tumor tissue samples. Whole mtDNA sequence was determined by MitoChip v2.0 mitochondrial resequencing array, and data were analyzed using the GeneChip Sequence Analysis Software. Tumor mtDNA sequence was compared with matched leukocyte mtDNA sequence. RESULTS: Three women had a normal BMI and three presented obesity. Overall, we found 64 genetic variants: 53.1% were somatic mutations and 46.9% were polymorphisms; 44.1% were in the non-coding region and 55.9% were in genes that encode for mitochondrial proteins. Among the somatic mutations, 67.7% were in patients with normal BMI and 32.3% in patients with obesity. CONCLUSIONS: We did not find a higher frequency of mitochondrial somatic mutations in postmenopausal women with breast cancer and obesity compared to those with normal BMI. However, results could be due to the small number of women studied.

Whole sequencing of the mitochondrial genome of breast cancer tissue in Mexican-mestizo postmenopausal women with different body mass index

Abstract Background Mitochondrial and oxidative stress has been related to obesity and breast cancer being this cancer more frequent and more aggressive in postmenopausal women with obesity. Objective The objective of this study was to investigate whether Mexican-Mestizo postmenopausal women with breast cancer and obesity present different somatic mutations in the mitochondrial DNA (mtDNA) when compared to women with normal body mass index (BMI). Subjects and Methods We included six Mexican-Mestizo postmenopausal women bearing breast cancer and who underwent mastectomy or breast-conserving surgery. BMI was determined in each case. Patients’ genomic DNA was isolated from blood leukocytes and tumor tissue samples. Whole mtDNA sequence was determined by MitoChip v2.0 mitochondrial resequencing array, and data were analyzed using the GeneChip Sequence Analysis Software. Tumor mtDNA sequence was compared with matched leukocyte mtDNA sequence. Results Three women had a normal BMI and three presented obesity. Overall, we found 64 genetic variants: 53.1% were somatic mutations and 46.9% were polymorphisms; 44.1% were in the non-coding region and 55.9% were in genes that encode for mitochondrial proteins. Among the somatic mutations, 67.7% were in patients with normal BMI and 32.3% in patients with obesity. Conclusions We did not find a higher frequency of mitochondrial somatic mutations in postmenopausal women with breast cancer and obesity compared to those with normal BMI. However, results could be due to the small number of women studied.

Complete mitochondrial genome of the Ijima's Sea Snake (Emydocephalus ijimae) (Squamata, Elapidae).

In this study, we provide the first report of the complete mitochondrial genome of Emydocephalus ijimae. The mitogenome length is 18,259 bp and includes 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and three non-coding regions. The sequence presented could be very useful for further phylogenetic and evolutionary study.