ATP6 Gene Research Articles

On the Issue of Larix × lubarskii Sukaczev Origin: Analysis of Polymorphism of Mitochondrial Genome Markers

The genetic diversity of Larix × lubarskii Sukaczev and its genetic relationships to other larches from the south of Primorsky krai and Far Eastern and Siberian Larix species were for the first time studied according to the analysis of the UBC460 mitochondrial origin fragment length polymorphism and nucleotide sequences of the 5'-flanking region of the atpA gene and nad4(3c–4r) region in mitochondrial DNA. Two length variants of the UBC460 fragment were detected in the L. × lubarskii population (with a predominance of the short one). This taxon is characterized by an average haplotype (0.582) and low nucleotide (0.0003) diversity. The comparative analysis of nucleotide polymorphism of two mtDNA regions in larches from the south of Primorsky krai revealed three mitotypes in L. × lubarskii; only one of them was common with L. olgensis A. Henry (locus classicus). The network of mitotype genealogical relationships indicates a common origin of L. × lubarskii and L. olgensis and their relatively recent divergence, as well as a closer relationship to L. sibirica Ledeb. than to L. gmelinii (Rupr.) Rupr.

Characterization of mitochondrial genomes of three Andrena bees (Apoidea: Andrenidae) and insights into the phylogenetics.

Andrena is a large bee genus of >1500 species, which includes many important pollinators of agricultural systems. In this study, we present three mitochondrial genomes (mitogenomes) of Andrena species, which are the pollinators of Camellia oleifera. Compared with putative ancestral gene arrangement of insects, the three mitogenomes present identical gene rearrangement events, including local inversion (trnR) and gene shuffling (trnQ/trnM, trnK/trnD, and trnW/trnC-trnY). Most PCGs initiate with standard ATN codon and share the stop codon of TAA or TAG, whereas truncated stop codon T was detected in the atp6 gene of A. chekiangensis. Furthermore, the nad4 gene end with a single T in all three Andrena species. All tRNAs could be folded into clover-leaf secondary structure except for trnS1, with the dihydrouracil (DHU) arm forming a simple loop. Phylogenetic analysis is performed on 17 Andrena mitogenomes. Maximum likelihood and Bayesian methods generate identical topology, in which A. hunanensis and A. striata form a group and are close to A. camellia. Although A. chekiangensis is also difficult to be distinguished from A. camellia by morphological methods, A. chekiangensis and A. haemorrhoa form a clade and are grouped with the other taxa of the genus Andrena.

Complete mitochondrial genome of the Antarctic copepod Tigriopus kingsejongenesis (Harpacticoida, Harpacticidae)

The complete mitochondrial genome was sequenced from the Antarctic harpacticoid copepod Tigriopus kingsejongensis. The sequenced genome size was 14,940 bp, possessing different gene order and contents to those of the congeneric species T. japonicus and T. californicus in the genus Tigriopus. The mitochondrial genome of T. kingsejongensis has 13 protein-coding genes (PCGs), 2 rRNAs, and 22 tRNAs. Of the 13 PCGs, CO1, ND3, ATP6, and CO3 genes had incomplete stop codons T–, T–, TA–, and T–, respectively. Furthermore, the stop codons of the remaining 11 PCGs were TAA or TAG, while the start codon of 13 PCGs was ATG (CO1, ND4, Cytb, ND2, ND1, CO2, ND6, ATP6, CO3 genes), ATT (ND5, ATP8 genes), and ATA (ND3, ND4L genes), respectively. The nucleotide of 13 PCGs of T. kingsejongensis mitogenome showed 53.42, 52.17, and 49.10% similarities to the copepods T. japonicus, T. californicus, and Amphiascoides atopus, respectively, while the amino acid similarities were 64.38, 63.86, and 62.40%, respectively.

Characterization of the complete mitochondrial genome of Crotalus adamanteus (Eastern diamondback rattlesnake)

In this study, the complete mitochondrial genome of Eastern diamondback rattlesnake, Crotalus adamanteus, was recovered through Illumina sequencing data. This complete mitochondrial genome of C. adamanteus is 17,406 bp in length and has a base composition of A (32.3%), T (24.7%), C (29.7%), G (13.3%), demonstrating a bias of higher AT content (57.0%) than GC content (43.0%). The mitochondrial genome contains a typically conserved structure among Crotalinae mitogenomes, encoding 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (12S rRNA and 16S rRNA) and a control region (D-loop region). Twelve PCGs were located on the H-strand, except ND6 that was located on the L-strand. ATP8 gene and ATP6 gene were overlapped by 9 bp. The whole mt genome of C. adamanteus and other Viperidae mitogenomes (44 species, in total) were used for phylogenetic analysis. The result indicated C. adamanteus clustered with Crotalus horridus (HM641837.1), representing a distinct genus, which has the closest relationship with Bothrops jararaca (KU194299.1).

The complete mitochondrial genome of the tree frog, Polypedates braueri (Anura, Rhacophoridae)

We determined the complete mitochondrial genome of the tree frog, Polypedates braueri using next generation sequencing (NGS) and Sanger sequencing. The mitogenome of P. braueri was 19,904 bp in length, which contained 12 protein-coding genes, 22 tRNAs, two rRNAs, and two control regions (D-Loop). A noncoding sequence (NC) was discovered between tRNALys and ATP6 gene, as well as replaced the original position of ATP8 gene. The ND5 gene was found between the two control regions. More mitochondrial genomic information will contribute to revealing the phylogenetic relationships among species of the genus Polypedates.

Complete mitochondrial genome sequence of Mileewa albovittata (Hemiptera: Cicadellidae: Mileewinae)

The complete mitochondrial genome of Mileewa albovittata was sequenced and annotated from this study. The circular mitogenome is 15,079 bp in length, containing 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich region. The total length of 13 PCGs is 10,965 bp, responsible for encoding 3640 amino acids. Eleven PCGs have ATN as the start codon, except for ATP8 and NAD5 genes have TTG. Twelve PCGs have TAA as the stop codon, while the COII gene has an incomplete stop codon (A). The LSU and SSU of rRNA gene are 1220 bp and 749 bp, respectively. Novel insight on taxonomy of Cicadellidae was provided with phylogenetic analyses among mitogenome sequences from 20 related species.

The complete mitochondrial genome of Cylicocylus ashworthi (Rhabditida: Cyathostominae)

The complete mitochondrial genome sequence of Cylicocylus ashworthi was determined for the first time in the present study. The length of mtDNA sequences of C. ashworthi is 13,876 bp in size, containing 12 protein-coding genes (cox1-3, nad1-6, nad4L, atp6, and cytb), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and two non-coding regions. All genes are encoded by the same strand. The phylogenetic analysis by Bayesian inference method revealed that Cylicocylus genus was present in the same clade with high statistical support, and C. ashworthi was closely related with Cylicocylus nassatus than to other Strongylidae nematodes. The complete mt genome provide useful genetic marker for further studies of the taxonomy and systematics of Cyathostominae nematodes.

Characterization of the complete mitochondrial genome of Hermissenda emurai (Baba, 1937) (Nudibranchia, Facelinidae)

Hermissenda emurai is a species of sea slugs in the northwestern Pacific region. In this study, the complete mitochondrial genome of H. emurai (Mollusca: Facelinidae) collected from Korea was recorded. The assembled mitogenome of H. emurai was circular and 13,880 bp in length, including 27.1% A, 15.9% C, 20.5% G, and 36.5% T nucleotide distributions. The overall A–T composition was 63.6% while the G–C composition was 36.4%. Phylogenetic analysis according to 12 protein coding genes (atp8 gene excluded) showed that H. emurai clustered with Sakuraeolis japonica in the order Nudibranchia.

Evolutionary Analysis of Plastid Genomes of Seven Lonicera L. Species: Implications for Sequence Divergence and Phylogenetic Relationships.

Plant plastomes play crucial roles in species evolution and phylogenetic reconstruction studies due to being maternally inherited and due to the moderate evolutionary rate of genomes. However, patterns of sequence divergence and molecular evolution of the plastid genomes in the horticulturally- and economically-important Lonicera L. species are poorly understood. In this study, we collected the complete plastomes of seven Lonicera species and determined the various repeat sequence variations and protein sequence evolution by comparative genomic analysis. A total of 498 repeats were identified in plastid genomes, which included tandem (130), dispersed (277), and palindromic (91) types of repeat variations. Simple sequence repeat (SSR) elements analysis indicated the enriched SSRs in seven genomes to be mononucleotides, followed by tetra-nucleotides, dinucleotides, tri-nucleotides, hex-nucleotides, and penta-nucleotides. We identified 18 divergence hotspot regions (rps15, rps16, rps18, rpl23, psaJ, infA, ycf1, trnN-GUU-ndhF, rpoC2-rpoC1, rbcL-psaI, trnI-CAU-ycf2, psbZ-trnG-UCC, trnK-UUU-rps16, infA-rps8, rpl14-rpl16, trnV-GAC-rrn16, trnL-UAA intron, and rps12-clpP) that could be used as the potential molecular genetic markers for the further study of population genetics and phylogenetic evolution of Lonicera species. We found that a large number of repeat sequences were distributed in the divergence hotspots of plastid genomes. Interestingly, 16 genes were determined under positive selection, which included four genes for the subunits of ribosome proteins (rps7, rpl2, rpl16, and rpl22), three genes for the subunits of photosystem proteins (psaJ, psbC, and ycf4), three NADH oxidoreductase genes (ndhB, ndhH, and ndhK), two subunits of ATP genes (atpA and atpB), and four other genes (infA, rbcL, ycf1, and ycf2). Phylogenetic analysis based on the whole plastome demonstrated that the seven Lonicera species form a highly-supported monophyletic clade. The availability of these plastid genomes provides important genetic information for further species identification and biological research on Lonicera.

Positive Selection Drove the Adaptation of Mitochondrial Genes to the Demands of Flight and High-Altitude Environments in Grasshoppers.

The molecular evolution of mitochondrial genes responds to changes in energy requirements and to high altitude adaptation in animals, but this has not been fully explored in invertebrates. The evolution of atmospheric oxygen content from high to low necessarily affects the energy requirements of insect movement. We examined 13 mitochondrial protein-coding genes (PCGs) of grasshoppers to test whether the adaptive evolution of genes involved in energy metabolism occurs in changes in atmospheric oxygen content and high altitude adaptation. Our molecular evolutionary analysis of the 13 PCGs in 15 species of flying grasshoppers and 13 related flightless grasshoppers indicated that, similar to previous studies, flightless grasshoppers have experienced relaxed selection. We found evidence of significant positive selection in the genes ATP8, COX3, ND2, ND4, ND4L, ND5, and ND6 in flying lineages. This results suggested that episodic positive selection allowed the mitochondrial genes of flying grasshoppers to adapt to increased energy demands during the continuous reduction of atmospheric oxygen content. Our analysis of five grasshopper endemic to the Tibetan Plateau and 13 non-Tibetan grasshoppers indicated that, due to positive selection, more non-synonymous nucleotide substitutions accumulated in Tibetan grasshoppers than in non-Tibetan grasshoppers. We also found evidence for significant positive selection in the genes ATP6, ND2, ND3, ND4, and ND5 in Tibetan lineages. Our results thus strongly suggest that, in grasshoppers, positive selection drives mitochondrial genes to better adapt both to the energy requirements of flight and to the high altitude of the Tibetan Plateau.

Sequencing of organellar genomes of Gymnomitrion concinnatum (Jungermanniales) revealed the first exception in the structure and gene order of evolutionary stable liverworts mitogenomes

BackgroundComparative analyses of chloroplast and mitochondrial genomes have shown that organelle genomes in bryophytes evolve slowly. However, in contrast to seed plants, the organellar genomes are yet poorly explored in bryophytes, especially among liverworts. Discovering another organellar genomes of liverwort species by sequencing provides new conclusions on evolution of bryophytes.ResultsIn this work, the organellar genomes of Gymnomitrion concinnatum liverwort were sequenced, assembled and annotated for the first time. The chloroplast genome displays, typical for most plants, quadripartite structure containing large single copy region (81,701 bp), two inverted repeat regions (8704 bp each) and small single copy region (20,179 bp). The gene order and content of chloroplast are very similar to other liverworts with minor differences observed. A total number of 739 and 222 RNA editing sites were predicted in chloroplast and mitochondrial genes of G. concinnatum. The mitochondrial genome gene content is also in accordance with liverworts except few alterations such as: intron loss in cox1 and atp1 genes. Nonetheless the analysis revealed that G. concinnatum mitogenome structure and gene order are rearranged in comparison with other mitogenomes of liverworts. The causes underlying such mitogenomic rearrangement were investigated and the probable model of recombination was proposed.ConclusionsThis study provide the overview of mitochondrial and chloroplast genome structure and gene order diversity of Gymnomitrion concinnatum against the background of known organellar genomes of liverworts. The obtained results cast doubt on the idea that mitogenome structure of early land plants is highly conserved as previous studies suggested. In fact is the very first case of recombination within, evolutionary stable, mitogenomes of liverworts.

Phylogenetic Uniqueness of Honeybee Apis Cerana from the Korean Peninsula Inferred from The Mitochondrial, Nuclear, and Morphological Data

Abstract Apis cerana is an Eastern honeybee species distributed throughout Asia and closely related to the Western honeybee species Apis mellifera distributed across all of Africa, Europe and Western Asia, and subdivided into thirty confirmed subspecies. Currently, A. cerana is an endangered bee species in contrast to A. mellifera. We sequenced and annotated the complete mitochondrial genome of A. cerana from the Jeollanam-do province of South Korea and uploaded to the DDBJ/Genbank database(AP018431). MtDNA sequence is 15.925 bp long, has 84% AT-content and 16% GC-content and contains 22 tRNA genes, 13 protein-coding genes, two ribosomal RNA genes, one AT-rich region and four non-coding intergenic regions (NC1-4). All protein-coding genes are started by ATT and ATG codons, except the genes ATP8 and ND4, which started by ATC and ATA, respectively, and are stopped by the common codons TAA and TAG. A comparative analysis of the whole mtDNA sequences of A. cerana from Korea and Taiwan, A. c. cerana from China and A. c. japonica from Japan showed that the genetic divergence of the Korean A. cerana sample from subspecies A. c. cerana (2.57%) and A. c. japonica (2.58%) matched to the level of genetic divergence of mtDNA between animal subspecies (0.8-8%). Based on the comparative analysis of complete mtDNA (~16,000 bp), two nuclear gene VG and EF1- α sequences (~8,000 bp) and morphological measurements (six parameters), we assumed that Korean A. cerana, Chinese A. c. cerana and Japanese A. c. japonica are different subspecies at an early stage of sub-speciation and could be called further as subspecies of Apis cerana koreana.

NUEVOS MARCADORES MITOCONDRIALES MEJORAN LA FILOGENIA DE LA TORTUGA CAREY Eretmochelys imbricata (TESTUDINES: CHELONIIDAE)

The sea turtles (Cheloniidae) are a group of seven species of cretaceous origin. Analyses of partial mitochondrial sequences have revealed phylogenetic inconsistences within this group. Nevertheless, these mitochondrial markers have allowed us to understand, explain and clarify population composition in areas of foraging, reproductive habits, inferences of migration patterns and, also, to define management units in the world, in order to trace conservation and monitoring plans. In this study, four methods were evaluated and compared for phylogenetic inference (Neighbor-Joining-NJ, Maximum Likelihood-ML, Maximum Parsimony-MP and Bayesian inference-BI) by using coding genes, ribosomal genes and full mitogenomes of the hawksbill, E. imbricata, and other six species of sea turtles obtained from GenBank. The sequences were analyzed independently and jointly to identify the method and marker that better explain the phylogenetic relationships among this group of reptiles. The NJ, ML, MP and BI trees showed that ND2, COX1, 16S rRNA, ND5, 12S rRNA, ND4 and COX3 are the markers that give phylogenetic trees with better resolution and support, with bootstrap values ranging from 89.0% to 99.98%. ATP6, ATP8, COX2, ND1, ND3, ND5 and ND4L genes presented polytomies. The analysis with full mitogenome often provides highly supported trees (bootstrap 98.0%) compared with single marker analysis. Trees obtained with the BI method and the ND2 gene is the one that better resolved the evolutionary relationships among the species, consolidating the position of E. imbricata within the Carettini tribe with a value of posterior probability of 0.98-1.0. The markers ND2, ND4, ND5 and COIII, not used in previous works, represent a new alternative to explain the phylogeny in this group of marine reptiles. In the present study, a complete mitogenome analysis produced robust and highly supported trees. Key words: phylogenetic relationships, Eretmochelys imbricate, mitogenoma, sea turtles, bootstrap, polytomies

Mitochondrial Genome Variation Affects Multiple Respiration and Nonrespiration Phenotypes in Saccharomyces cerevisiae.

Mitochondrial genome variation and its effects on phenotypes have been widely analyzed in higher eukaryotes but less so in the model eukaryote Saccharomyces cerevisiae Here, we describe mitochondrial genome variation in 96 diverse S. cerevisiae strains and assess associations between mitochondrial genotype and phenotypes as well as nuclear-mitochondrial epistasis. We associate sensitivity to the ATP synthase inhibitor oligomycin with SNPs in the mitochondrially encoded ATP6 gene. We describe the use of iso-nuclear F1 pairs, the mitochondrial genome equivalent of reciprocal hemizygosity analysis, to identify and analyze mitochondrial genotype-dependent phenotypes. Using iso-nuclear F1 pairs, we analyze the oligomycin phenotype-ATP6 association and find extensive nuclear-mitochondrial epistasis. Similarly, in iso-nuclear F1 pairs, we identify many additional mitochondrial genotype-dependent respiration phenotypes, for which there was no association in the 96 strains, and again find extensive nuclear-mitochondrial epistasis that likely contributes to the lack of association in the 96 strains. Finally, in iso-nuclear F1 pairs, we identify novel mitochondrial genotype-dependent nonrespiration phenotypes: resistance to cycloheximide, ketoconazole, and copper. We discuss potential mechanisms and the implications of mitochondrial genotype and of nuclear-mitochondrial epistasis effects on respiratory and nonrespiratory quantitative traits.

Genetic variation of the nuclear sequences of mitochondrial origin associated with retrotransposon Tv1 insertions in Drosophila species of the virilis group

Mitochondrial DNA sequences integrated into chromosomes are a promising object for designing genetic markers for studies of phylogenesis and genomic instability. Mitochondrial genomes of D. virilis and other Drosophila species of the virilis group contain (AT)nmicrosatellites in the spacer region between the atp6 and cox3 genes, and this microsatellite sequence is one of the hallmarks of the virilis group. The nuclear genome of D. virilis contains many extended fragments of mitochondrial DNA, which in total are several times longer than the mitochondrial genome. These nuclear sequences of mitochondrial origin contain all types of mitochondrial sequences, including mitochondrial genes and the aforementioned microsatellite sequence. The presence of the (AT)nmicrosatellite allows insertion of retrotransposon Tv1, which can transpose into the (AT)n microsatellite in a site-specific manner. The Tv1 insertion into (AT)n, close to the atp6 or cox3 pseudogenes produces a unique sequence. This sequence is formed by retrotransposon Tv1 and pseudogenes atp6 or cox3. This unique sequence can be detected in the genome by a PCR-based method. We applied this method to the detection and analysis of the nucleotide variability of the pseudogenes atp6 and cox3 associated with Tv1 insertions in a D. virilis cell culture and in the genomes of four Drosophila species of the virilis group: D. virilis, D. montana, D. borealis, and D. lacicola. We discovered new events of mitochondrial sequence transfer to the nucleus in the transplanted cell culture of D. virilis, and new Tv1 insertions, having emerged during the passage of this cell line were detected in the genome of the D. virilis transplanted cell culture. We found atp6 and cox3 pseudogenes associated with insertions of retrotransposon Tv1 in the nuclear genomes of four Drosophila species from the virilis group. These chimeric sequences proved to be species-specific. The age of the Tv1 insertion into the atp6 and cox3 pseudogenes is estimated at 1.50 Ma for D. virilis, 1.31 Ma for D. lacicola, and 1.56 Ma for D. borealis. A specific situation was revealed for D. montana, in which Tv1 insertions with nearly identical 5' and 3' long terminal repeats (LTRs) were present in accessions of flies from Europe and Asia. The age of this insertion was about 300 thousand years, and the insertion was absent from the D. montana fly line from North America.

Functional investigation of an universally conserved leucine residue in subunit a of ATP synthase targeted by the pathogenic m.9176 T>G mutation

Protons are transported from the mitochondrial matrix to the intermembrane space of mitochondria during the transfer of electrons to oxygen and shuttled back to the matrix by the a subunit and a ring of identical c subunits across the membrane domain (FO) of ATP synthase, which is coupled to ATP synthesis. A mutation (m.9176 T > G) of the mitochondrial ATP6 gene that replaces an universally conserved leucine residue into arginine at amino acid position 217 of human subunit a (aL217R) has been associated to NARP (Neuropathy, Ataxia and Retinitis Pigmentosa) and MILS (Maternally Inherited Leigh's Syndrome) diseases. We previously showed that an equivalent thereof in Saccharomyces cerevisiae (aL237R) severely impairs subunit a assembly/stability and decreases by >90% the rate of mitochondrial ATP synthesis. Herein we identified three spontaneous first-site intragenic suppressors (aR237M, aR237T and aR237S) that fully restore ATP synthase assembly. However, mitochondrial ATP synthesis rate was only partially recovered (40–50% vs wild type yeast). In light of recently described high-resolution yeast ATP synthase structures, the detrimental consequences of the aL237R change can be explained by steric and electrostatic hindrance with the universally conserved subunit a arginine residue (aR176) that is essential to FO activity. aL237 together with three other nearby hydrophobic residues have been proposed to prevent ion shortage between two physically separated hydrophilic pockets within the FO. Our results suggest that aL237 favors subunit c-ring rotation by optimizing electrostatic interaction between aR176 and an acidic residue in subunit c (cE59) known to be essential also to the activity of FO.

Genetic Diversity in Echinococcus multilocularis From the Plateau Vole and Plateau Pika in Jiuzhi County, Qinghai Province, China.

The Qinghai-Tibet Plateau is a highly endemic area of alveolar echinococcosis where a series of intermediate hosts, especially voles and pikas, are infected with Echinococcus multilocularis. The metacestodes of E. multilocularis are fluid-filled, asexually proliferating cysts, and they are mainly found in the host's liver in the form of tumor-like growths. In this study, we investigated the genetic variations of E. multilocularis in four mitochondrial (mt) genes, namely, NADH dehydrogenase subunit 5 (nad5), adenosine triphosphate subunit 6 (atp6), cytochrome c oxidase subunit 1 (cox1), and NADH dehydrogenase subunit 1 (nad1). The complete nad5, atp6, cox1, and nad1 genes were amplified separately from each hydatid cyst isolate using polymerase chain reaction (PCR) and then sequenced. Phylogenetic trees were then generated based on the combined mt genes using MrBayes 3.1.2 and PAUP version 4.0b10. The results showed that thirty of 102 voles and two of 49 pikas were infected with E. multilocularis. The genetic variation distances among all E. multilocularis samples were 0.1–0.4%, 0.2–0.4%, 0.1–0.6%, and 0.1–0.4% for nad5, atp6, nad1, and cox1, respectively. Compared to previous studies of the genetic diversity of E. multilocularis based on the cox1 gene, the genetic distances within the same group were 1.3–1.7% (Mongolia strain), 0.6–0.8% (North American strain), 0.3–0.6% (European strain), and 0.1–0.4% (Asian strain). Based on concatenated sequences of the nad5, atp6, cox1, and nad1 genes all haplotypes were divided into two clusters. In conclusion, the genetic diversity of E. multilocularis based on mt genes on a small local area is at low level but between different regions with long distance and different ecological environment each other, the genetic diversity is at relatively high level; genetic variation is higher in the nad1 gene than that in the other three mt genes. The results on a local scale provide basic information for further study of the molecular epidemiology, genetic differences and control of E. multilocularis in Qinghai Province, China.

Mitochondrial Polymorphism of Native and Invasive Populations of Harmonia axyridis (Coleoptera, Coccinellidae)

Ladybird Harmonia axyridis is a widespread polyphage and forms stable populations in East Asia and spreading invasive populations in Europe and other regions with temperate and subtropical climate. A characteristic of haplotype diversity of native and invasive populations of H. axyridis at the atp6 gene is given. The characteristic differences in the composition and quantitative ratio of mitochondrial haplotypes between the western and eastern groups of populations of the native range are revealed. The genetic structure of invasive populations is uniform across the whole range in Europe, from the Atlantic coast to the Black Sea coast of the Caucasus, which is indicative of the spread of H. axyridis invasive populations in Europe from one center. In Europe, the mitochondrial gene pool of invasive populations is formed by two major haplotypes. This mitochondrial haplotype composition remains unchanged in the process of the invasion expansion. The possible role of mixed origin of invasive populations of H. axyridis in the formation of the invasive ability is discussed.

High genetic diversity in the Dirofilaria repens species complex revealed by mitochondrial genomes of feline microfilaria samples from Narathiwat, Thailand.

Dirofilaria repens is a zoonotic, mosquito-borne filaria infecting carnivores, particularly dogs. It is expanding its range in Europe but epidemiological information is sparse for other Eurasian regions. In Hong Kong and India, the closely related species Candidatus Dirofilaria hongkongensis was proposed. Previous analysis of 2.5kb partial mitochondrial genome sequences containing the particularly variable non-coding control region revealed low diversity in European D.repens while Asian nematodes showed high diversity. Sequences derived from feline blood samples from Narathiwat (Thailand) led to the proposal of a third potential species, Dirofilaria sp. "Thailand II". To avoid bias from rapidly evolving non-coding regions, this study aimed to compare Dirofilaria sp. "Thailand II" with D.repens and C. D.hongkongensis based on complete mitochondrial genomes. Using PCRs and Sanger sequencing, three complete mitochondrial genomes (13,651bp) were assembled from DNA obtained from different feline blood samples. Mitochondrial genome organization was identical to other onchocercids with eleven protein-coding, two rRNA and 22 tRNA genes and no atp-8 gene. All genes were on the same strand showing an extremely high thymidine content (56.7%). Maximum-likelihood phylogenetic analysis using protein and rRNA sequences confirmed closer relationship of Dirofilaria sp. "Thailand II" to C. D.hongkongensis than to D.repens. All distances between these three putative species were considerably larger than the distance between the valid sibling species Onchocerca volvulus and Onchocerca ochengi. Sequencing of a 2.5kb fragment containing the control region from microfilarial DNA from additional feline blood samples from Narathiwat 3-4years later revealed that these also fell into the C. D.hongkongensis clade but were remarkably different from C. D.hongkongensis and Dirofilaria sp. "Thailand II". Since D.repens-like filaria are absent from dogs in Narathiwat, further field studies are required to confirm if these genotypes represent locally circulating cat-specific Dirofilaria genotypes or species.

OnPLS-Based Multi-Block Data Integration: A Multivariate Approach to Interrogating Biological Interactions in Asthma.

Integration of multiomics data remains a key challenge in fulfilling the potential of comprehensive systems biology. Multiple-block orthogonal projections to latent structures (OnPLS) is a projection method that simultaneously models multiple data matrices, reducing feature space without relying on a priori biological knowledge. In order to improve the interpretability of OnPLS models, the associated multi-block variable influence on orthogonal projections (MB-VIOP) method is used to identify variables with the highest contribution to the model. This study combined OnPLS and MB-VIOP with interactive visualization methods to interrogate an exemplar multiomics study, using a subset of 22 individuals from an asthma cohort. Joint data structure in six data blocks was assessed: transcriptomics; metabolomics; targeted assays for sphingolipids, oxylipins, and fatty acids; and a clinical block including lung function, immune cell differentials, and cytokines. The model identified seven components, two of which had contributions from all blocks (globally joint structure) and five that had contributions from two to five blocks (locally joint structure). Components 1 and 2 were the most informative, identifying differences between healthy controls and asthmatics and a disease–sex interaction, respectively. The interactions between features selected by MB-VIOP were visualized using chord plots, yielding putative novel insights into asthma disease pathogenesis, the effects of asthma treatment, and biological roles of uncharacterized genes. For example, the gene ATP6 V1G1, which has been implicated in osteoporosis, correlated with metabolites that are dysregulated by inhaled corticoid steroids (ICS), providing insight into the mechanisms underlying bone density loss in asthma patients taking ICS. These results show the potential for OnPLS, combined with MB-VIOP variable selection and interaction visualization techniques, to generate hypotheses from multiomics studies and inform biology.