Mitochondrial genomes of the genus Ephydatia Lamouroux, 1816: can palindromic elements be used in species-level studies?

Poriferan mitochondrial DNA (mtDNA), especially large intergenic regions, is a target for the insertion of repetitive hairpin-forming elements. These elements are responsible for the large mt genome size differences observed even among closely related sponge taxa. In this study, we present the new, nearly complete, mt genome sequence of Ephydatia fluviatilis and compare it with previously published mt genomes of freshwater sponges. Special emphasis was placed on comparison with the closely related species Ephydatia muelleri, thereby comparing the only two species of the genus Ephydatia on the western Balkan Peninsula. In particular, we analyzed repetitive palindromic elements within the mitochondrial intergenic regions. The genomic distribution of these repetitive elements was analyzed and their potential role in the evolution of mt genomes discussed. We show here that palindromic elements are widespread through the whole mt genome, including the protein coding genes, thus introducing genetic variability into mt genomes.     

The first complete mitochondrial genome from Bostrychus genus (Bostrychus sinensis) and partitioned Bayesian analysis of Eleotridae fish phylogeny

To understand the phylogenetic position of Bostrychus sinensis in Eleotridae and the phylogenetic relationships of the family, we determined the nucleotide sequence of the mitochondrial (mt) genome of Bostrychus sinensis. It is the first complete mitochondrial genome sequence of Bostrychus genus. The entire mtDNA sequence was 16508 bp in length with a standard set of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a noncoding control region. The mitochondrial genome of B. sinensis had common features with those of other bony fishes with respect to gene arrangement, base composition, and tRNA structures. Phylogenetic hypotheses within Eleotridae fish have been controversial at the genus level. We used the mitochondrial cytochrome b (cytb) gene sequence to examine phylogenetic relationships of Eleotridae by using partitioned Bayesian method. When the specific models and parameter estimates were presumed for partitioning the total data, the harmonic mean –lnL was improved. The phylogenetic analysis supported the monophyly of Hypseleotris and Gobiomorphs. In addition, the Bostrychus were most closely related to Ophiocara, and the Philypnodon is also the sister to Microphlypnus, based on the current datasets. Further, extensive taxonomic sampling and more molecular information are needed to confirm the phylogenetic relationships in Eleotridae.     

The mitochondrial genome of Baylisascaris procyonis

Background

Baylisascaris procyonis (Nematoda: Ascaridida), an intestinal nematode of raccoons, is emerging as an important helminthic zoonosis due to serious or fatal larval migrans in animals and humans. Despite its significant veterinary and public health impact, the epidemiology, molecular ecology and population genetics of this parasite remain largely unexplored. Mitochondrial (mt) genomes can provide a foundation for investigations in these areas and assist in the diagnosis and control of B. procyonis. In this study, the first complete mt genome sequence of B. procyonis was determined using a polymerase chain reaction (PCR)-based primer-walking strategy.

Methodology/Principal Findings

The circular mt genome (14781 bp) of B. procyonis contained 12 protein-coding, 22 transfer RNA and 2 ribosomal RNA genes congruent with other chromadorean nematodes. Interestingly, the B. procyonis mtDNA featured an extremely long AT-rich region (1375 bp) and a high number of intergenic spacers (17), making it unique compared with other secernentean nematodes characterized to date. Additionally, the entire genome displayed notable levels of AT skew and GC skew. Based on pairwise comparisons and sliding window analysis of mt genes among the available 11 Ascaridida mtDNAs, new primer pairs were designed to amplify specific short fragments of the genes cytb (548 bp fragment) and rrnL (200 bp fragment) in the B. procyonis mtDNA, and tested as possible alternatives to existing mt molecular beacons for Ascaridida. Finally, phylogenetic analysis of mtDNAs provided novel estimates of the interrelationships of Baylisasaris and Ascaridida.

Conclusions/Significance

The complete mt genome sequence of B. procyonis sequenced here should contribute to molecular diagnostic methods, epidemiological investigations and ecological studies of B. procyonis and other related ascaridoids. The information will be important in refining the phylogenetic relationships within the order Ascaridida and enriching the resource of markers for systematic, population genetic and evolutionary biological studies of parasitic nematodes of socio-economic importance.     

The Mitochondrial Genome of Paramphistomum cervi (Digenea), the First Representative for the Family Paramphistomidae

We determined the complete mitochondrial DNA (mtDNA) sequence of a fluke, Paramphistomum cervi (Digenea: Paramphistomidae). This genome (14,014 bp) is slightly larger than that of Clonorchis sinensis (13,875 bp), but smaller than those of other digenean species. The mt genome of P. cervi contains 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (NCRs), a complement consistent with those of other digeneans. The arrangement of protein-coding and ribosomal RNA genes in the P. cervi mitochondrial genome is identical to that of other digeneans except for a group of Schistosoma species that exhibit a derived arrangement. The positions of some transfer RNA genes differ. Bayesian phylogenetic analyses, based on concatenated nucleotide sequences and amino-acid sequences of the 12 protein-coding genes, placed P. cervi within the Order Plagiorchiida, but relationships depicted within that order were not quite as expected from previous studies. The complete mtDNA sequence of P. cervi provides important genetic markers for diagnostics, ecological and evolutionary studies of digeneans.     

Decoding and analysis of organelle genomes of Indian tea (Camellia assamica) for phylogenetic confirmation

The NCBI database has >15 chloroplast (cp) genome sequences available for different Camellia species but none for C. assamica. There is no report of any mitochondrial (mt) genome in the Camellia genus or Theaceae family. With the strong believes that these organelle genomes can play a great tool for taxonomic and phylogenetic analysis, we successfully assembled and analyzed cp and mt genome of C. assamica. We assembled the complete mt genome of C. assamica in a single circular contig of 707,441 bp length comprising of a total of 66 annotated genes, including 35 protein-coding genes, 29 tRNAs and two rRNAs. The first ever cp genome of C. assamica resulted in a circular contig of 157,353 bp length with a typical quadripartite structure. Phylogenetic analysis based on these organelle genomes showed that C. assamica was closely related to C. sinensis and C. leptophylla. It also supports Caryophyllales as Superasterids.     

The mitochondrial genome of Ifremeria nautilei and the phylogenetic position of the enigmatic deep-sea Abyssochrysoidea (Mollusca: Gastropoda)

The complete nucleotide sequence of the mitochondrial (mt) genome of the deep-sea vent snail Ifremeria nautilei (Gastropoda: Abyssochrysoidea) was determined. The double stranded circular molecule is 15,664 pb in length and encodes for the typical 37 metazoan mitochondrial genes. The gene arrangement of the Ifremeria mt genome is most similar to genome organization of caenogastropods and differs only on the relative position of the trnW gene. The deduced amino acid sequences of the mt protein coding genes of Ifremeria mt genome were aligned with orthologous sequences from representatives of the main lineages of gastropods and phylogenetic relationships were inferred. The reconstructed phylogeny supports that Ifremeria belongs to Caenogastropoda and that it is closely related to hypsogastropod superfamilies. Results were compared with a reconstructed nuclear-based phylogeny. Moreover, a relaxed molecular-clock timetree calibrated with fossils dated the divergence of Abyssochrysoidea in the Late Jurassic–Early Cretaceous indicating a relatively modern colonization of deep-sea environments by these snails.     

Characterization of the complete mitochondrial genome of Diplostomum baeri

Despite Diplostomum baeri (Dubois, 1937) being one of the most widely distributed parasites of freshwater fish, there is no complete mitochondrial (mt) genome currently available. The complicated systematics presented by D. baeri has hampered investigations into the species distributions and infective dynamics of the species. Within this study we obtained complete mt genome sequences of D. baeri and assessed its phylogenetic relationship with other species of Digenea. The complete mitochondrial genome of D. baeri is 14,480 bp in length, containing 36 genes in total. The phylogenetic tree resulting from Bayesian inference of concatenated 12 protein coding gene sequences placed D. baeri alongside published mt genomes of Diplostomidae, with the overall taxonomic placement of the genus being a sister lineage of the order Plagiochiida The characterization of further mitochondrial genomes within the family Diplostomidae will help progress phylogenetic and epidemiological investigations as well as providing a framework for the analysis of diagnostic markers to be used in further monitoring of the parasite worldwide.     

The 203 kbp Mitochondrial Genome of the Phytopathogenic Fungus Sclerotinia borealis Reveals Multiple Invasions of Introns and Genomic Duplications

Here we report the complete sequence of the mitochondrial (mt) genome of the necrotrophic phytopathogenic fungus Sclerotinia borealis, a member of the order Helotiales of Ascomycetes. The 203,051 bp long mtDNA of S. borealis represents one of the largest sequenced fungal mt genomes. The large size is mostly determined by the presence of mobile genetic elements, which include 61 introns. Introns contain a total of 125,394 bp, are scattered throughout the genome, and are found in 12 protein-coding genes and in the ribosomal RNA genes. Most introns contain complete or truncated ORFs that are related to homing endonucleases of the LAGLIDADG and GIY-YIG families. Integrations of mobile elements are also evidenced by the presence of two regions similar to fragments of inverton-like plasmids. Although duplications of some short genome regions, resulting in the appearance of truncated extra copies of genes, did occur, we found no evidences of extensive accumulation of repeat sequences accounting for mitochondrial genome size expansion in some other fungi. Comparisons of mtDNA of S. borealis with other members of the order Helotiales reveal considerable gene order conservation and a dynamic pattern of intron acquisition and loss during evolution. Our data are consistent with the hypothesis that horizontal DNA transfer has played a significant role in the evolution and size expansion of the S. borealis mt genome.     

Complete Mitochondrial Genome of Echinostoma hortense (Digenea: Echinostomatidae)

Echinostoma hortense (Digenea: Echinostomatidae) is one of the intestinal flukes with medical importance in humans. However, the mitochondrial (mt) genome of this fluke has not been known yet. The present study has determined the complete mt genome sequences of E. hortense and assessed the phylogenetic relationships with other digenean species for which the complete mt genome sequences are available in GenBank using concatenated amino acid sequences inferred from 12 protein-coding genes. The mt genome of E. hortense contained 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 non-coding region. The length of the mt genome of E. hortense was 14,994 bp, which was somewhat smaller than those of other trematode species. Phylogenetic analyses based on concatenated nucleotide sequence datasets for all 12 protein-coding genes using maximum parsimony (MP) method showed that E. hortense and Hypoderaeum conoideum gathered together, and they were closer to each other than to Fasciolidae and other echinostomatid trematodes. The availability of the complete mt genome sequences of E. hortense provides important genetic markers for diagnostics, population genetics, and evolutionary studies of digeneans.     

Complete mitochondrial genome of the Himalayan serow (Capricornis thar) and its phylogenetic status within the genus Capricornis

The genus Capricornis (Caprinae, Bovidae) includes six species, i.e., Capriconis sumatraensis, Capricornis swinhoei, Capricornis crispus, Capricornis rubidus, Capricornis milneedwardsii and Capricornis thar. Based on morphological, anatomical and physiological evidence, the Himalayan serow (C. thar), which is distributed in the mountain regions of the Tibetan Plateau and adjacent areas, is generally classified as a species of the genus Capricornis. However, considering the lack of molecular phylogenetic evidence, a heated controversy still exists over the taxonomic position of the Himalayan serow. To determine the phylogenetic status of C. thar, we sequenced the complete mitochondrial genome (mtDNA) of one Himalayan serow using the polymerase chain reaction (PCR) technique. Then, we constructed a molecular phylogenetic tree of the genus Capricornis and its related species in the Caprinae subfamily based on maximum likelihood and Bayesian interference methods. The results reflect that the structural characteristics, nucleotide content and codon usage bias of the mitochondrial genome of the Himalayan serow were similar to those of other serows. A phylogenetic analysis using two rRNA genes and 12 encoded protein-coding genes indicated that C. thar is clustered within the C. milneedwardsii clade, which is a sister group of C. sumatraensis. The present study provides useful information about the evolution of the Himalayan serow, which will be essential for conservation genetic studies.     

The First Complete Chloroplast Genome Sequences in Actinidiaceae: Genome Structure and Comparative Analysis

Actinidia chinensis is an important economic plant belonging to the basal lineage of the asterids. Availability of a complete Actinidia chloroplast genome sequence is crucial to understanding phylogenetic relationships among major lineages of angiosperms and facilitates kiwifruit genetic improvement. We report here the complete nucleotide sequences of the chloroplast genomes for Actinidia chinensis and A. chinensis var deliciosa obtained through de novo assembly of Illumina paired-end reads produced by total DNA sequencing. The total genome size ranges from 155,446 to 157,557 bp, with an inverted repeat (IR) of 24,013 to 24,391 bp, a large single copy region (LSC) of 87,984 to 88,337 bp and a small single copy region (SSC) of 20,332 to 20,336 bp. The genome encodes 113 different genes, including 79 unique protein-coding genes, 30 tRNA genes and 4 ribosomal RNA genes, with 16 duplicated in the inverted repeats, and a tRNA gene (trnfM-CAU) duplicated once in the LSC region. Comparisons of IR boundaries among four asterid species showed that IR/LSC borders were extended into the 5’ portion of the psbA gene and IR contraction occurred in Actinidia. The clap gene has been lost from the chloroplast genome in Actinidia, and may have been transferred to the nucleus during chloroplast evolution. Twenty-seven polymorphic simple sequence repeat (SSR) loci were identified in the Actinidia chloroplast genome. Maximum parsimony analyses of a 72-gene, 16 taxa angiosperm dataset strongly support the placement of Actinidiaceae in Ericales within the basal asterids.     

The Complete Maternally and Paternally Inherited Mitochondrial Genomes of the Endangered Freshwater Mussel Solenaia carinatus (Bivalvia: Unionidae) and Implications for Unionidae Taxonomy

Doubly uniparental inheritance (DUI) is an exception to the typical maternal inheritance of mitochondrial (mt) DNA in Metazoa, and found only in some bivalves. In species with DUI, there are two highly divergent gender-associated mt genomes: maternal (F) and paternal (M), which transmit independently and show different tissue localization. Solenaia carinatus is an endangered freshwater mussel species exclusive to Poyang Lake basin, China. Anthropogenic events in the watershed greatly threaten the survival of this species. Nevertheless, the taxonomy of S. carinatus based on shell morphology is confusing, and the subfamilial placement of the genus Solenaia remains unclear. In order to clarify the taxonomic status and discuss the phylogenetic implications of family Unionidae, the entire F and M mt genomes of S. carinatus were sequenced and compared with the mt genomes of diverse freshwater mussel species. The complete F and M mt genomes of S. carinatus are 16716 bp and 17102 bp in size, respectively. The F and M mt genomes of S. carinatus diverge by about 40% in nucleotide sequence and 48% in amino acid sequence. Compared to F counterparts, the M genome shows a more compact structure. Different gene arrangements are found in these two gender-associated mt genomes. Among these, the F genome cox2-rrnS gene order is considered to be a genome-level synapomorphy for female lineage of the subfamily Gonideinae. From maternal and paternal mtDNA perspectives, the phylogenetic analyses of Unionoida indicate that S. carinatus belongs to Gonideinae. The F and M clades in freshwater mussels are reciprocal monophyly. The phylogenetic trees advocate the classification of sampled Unionidae species into four subfamilies: Gonideinae, Ambleminae, Anodontinae, and Unioninae, which is supported by the morphological characteristics of glochidia.     

A unique tRNA gene family and a novel,highly expressed ORF in the mitochondrial genome of the silver-lip pearl oyster, Pinctada maxima (Bivalvia: Pteriidae)

Characteristics of mitochondrial (mt) DNA such as gene content and arrangement, as well as mt tRNA secondary structure, are frequently used in comparative genomic analyses because they provide valuable phylogenetic information. However, most analyses do not characterize the relationship of tRNA genes from the same mt genome and, in some cases, analyses overlook possible novel open reading frames (ORFs) when the 13 expected protein-coding genes are already annotated. In this study, we describe the sequence and characterization of the complete mt genome of the silver-lip pearl oyster, Pinctada maxima. The 16,994-bp mt genome contains the same 13 protein-coding genes (PCGs) and two ribosomal RNA genes typical of metazoans. The gene arrangement, however, is completely distinct from that of all other available bivalve mt genomes, and a unique tRNA gene family is observed in this genome. The unique tRNA gene family includes two trnS^− AGY and trnQ genes, a trnM isomerism, but it lacks trnS^− CUN. We also report the first clear evidence of alloacceptor tRNA gene recruitment (trnP → trnS^− AGY) in mollusks. In addition, a novel ORF (orfUR1) expressed at high levels is present in the mt genome of this pearl oyster. This gene contains a conserved domain, “Oxidored_q1_N”, which is a member of Complex I and thus may play an important role in key biological functions. Because orfUR1 has a very similar nucleotide composition and codon bias to that of other genes in this genome, we hypothesize that this gene may have been moved to the mt genome via gene transfer from the nuclear genome at an early stage of speciation of P. maxima, or it may have evolved as a result of gene duplication, followed by rapid sequence divergence. Lastly, a 319-bp region was identified as the possible control region (CR) even though it does not correspond to the longest non-coding region in the genome. Unlike other studies of mt genomes, this study compares the evolutionary patterns of all available bivalve mt tRNA and atp8 genes.     

Long-term conservation of six duplicated structural genes in cephalopod mitochondrial genomes

The complete nucleotide sequences of the mitochondrial (mt) genomes of three cephalopods, Octopus vulgaris (Octopodiformes, Octopoda, Incirrata), Todarodes pacificus (Decapodiformes, Oegopsida, Ommastrephidae), and Watasenia scintillans (Decapodiformes, Oegopsida, Enoploteuthidae), were determined. These three mt genomes encode the standard set of metazoan mt genes. However, W. scintillans and T. pacificus mt genomes share duplications of the longest noncoding region, three cytochrome oxidase subunit genes and two ATP synthase subunit genes, and the tRNA(Asp) gene. Southern hybridization analysis of the W. scintillans mt genome shows that this single genome carries both duplicated regions. The near-identical sequence of the duplicates suggests that there are certain concerted evolutionary mechanisms, at least in cephalopod mitochondria. Molecular phylogenetic analyses of mt protein genes are suggestive, although not statistically significantly so, of a monophyletic relationship between W. scintillans and T. pacificus.     

Plant mitochondrial rps2 genes code for proteins with a C-terminal extension that is processed

A gene (rps2) coding for ribosomal protein S2 (RPS2) is present in the mitochondrial (mt) genome of several monocot plants, but absent from the mtDNA of dicots. Confirming that in dicot plants the corresponding gene has been transferred to the nucleus, a corresponding Arabidopsis thaliana nuclear gene was identified that codes for mitochondrial RPS2. As several yeast and mammalian genes coding for mt ribosomal proteins, the Arabidopsis RPS2 apparently has no N-terminal targeting sequence. In the maize mt genome, two rps2 genes were identified and both are transcribed, although at different levels. As in wheat and rice, the maize genes code for proteins with long C-terminal extensions, as compared to their bacterial counterparts. These extensions are not conserved in sequence. Using specific antibodies against one of the maize proteins we found that a large protein precursor is indeed synthesized, but it is apparently processed to give the mature RPS2 protein which is associated with the mitochondrial ribosome.     

The First Mitochondrial Genomes of Antlion (Neuroptera: Myrmeleontidae) and Split-footed Lacewing (Neuroptera: Nymphidae), with Phylogenetic Implications of Myrmeleontiformia

In the holometabolous insect order Neuroptera (lacewings), the cosmopolitan Myrmeleontidae (antlions) are the most species-rich family, while the closely related Nymphidae (split-footed lacewings) are a small endemic family from the Australian-Malesian region. Both families belong to the suborder Myrmeleontiformia, within which controversial hypotheses on the interfamilial phylogenetic relationships exist. Herein, we describe the complete mitochondrial (mt) genomes of an antlion (Myrmeleon immanis Walker, 1853) and a split-footed lacewing (Nymphes myrmeleonoides Leach, 1814), representing the first mt genomes for both families. These mt genomes are relatively small (respectively composed of 15,799 and 15,713 bp) compared to other lacewing mt genomes, and comprise 37 genes (13 protein coding genes, 22 tRNA genes and two rRNA genes). The arrangement of these two mt genomes is the same as in most derived Neuroptera mt genomes previously sequenced, specifically with a translocation of trnC. The start codons of all PCGs are started by ATN, with an exception of cox1, which is ACG in the M. immanis mt genome and TCG in N. myrmeleonoides. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA, with the exception of trnS1(AGN). The secondary structures of rrnL and rrnS are similar with those proposed insects and the domain I contains nine helices rather than eight helices, which is common within Neuroptera. A phylogenetic analysis based on the mt genomic data for all Neuropterida sequenced thus far, supports the monophyly of Myrmeleontiformia and the sister relationship between Ascalaphidae and Myrmeleontidae.     

Mitochondrial Genome Analysis of Wild Rice (Oryza minuta) and Its Comparison with Other Related Species

Oryza minuta (Poaceae family) is a tetraploid wild relative of cultivated rice with a BBCC genome. O. minuta has the potential to resist against various pathogenic diseases such as bacterial blight (BB), white backed planthopper (WBPH) and brown plant hopper (BPH). Here, we sequenced and annotated the complete mitochondrial genome of O. minuta. The mtDNA genome is 515,022 bp, containing 60 protein coding genes, 31 tRNA genes and two rRNA genes. The mitochondrial genome organization and the gene content at the nucleotide level are highly similar (89%) to that of O. rufipogon. Comparison with other related species revealed that most of the genes with known function are conserved among the Poaceae members. Similarly, O. minuta mt genome shared 24 protein-coding genes, 15 tRNA genes and 1 ribosomal RNA gene with other rice species (indica and japonica). The evolutionary relationship and phylogenetic analysis revealed that O. minuta is more closely related to O. rufipogon than to any other related species. Such studies are essential to understand the evolutionary divergence among species and analyze common gene pools to combat risks in the current scenario of a changing environment.     

Closing the mitochondrial circle on paraphyly of the Monogenea (Platyhelminthes) infers evolution in the diet of parasitic flatworms

Relationships between the three classes of Neodermata (parasitic Platyhelminthes) are much debated and restrict our understanding of the evolution of parasitism and contingent adaptations. The historic view of a sister relationship between Cestoda and Monogenea (Cercomeromorphae; larvae bearing posterior hooks) has been dismissed and the weight of evidence against monogenean monophyly has mounted. We present the nucleotide sequence of the complete mitochondrial (mt) genome of Benedenia seriolae (Monogenea: Monopisthocotylea: Capsalidae), the first complete non-gyrodactylid monopisthocotylean mt genome to be reported. We also include nucleotide sequence data for some mt protein coding genes for a second capsalid, Neobenedenia sp. Analyses of the new mt genomes with all available platyhelminth mt genomes provide new phylogenetic hypotheses, which strongly influence perspectives on the evolution of diet in the Neodermata. Our analyses do not support monogenean monophyly but confirm that the Digenea and Cestoda are each monophyletic and sister groups. Epithelial feeding monopisthocotyleans on fish hosts are basal in the Neodermata and represent the first shift to parasitism from free-living ancestors. The next evolutionary step in parasitism was a dietary change from epithelium to blood. The common ancestor of Digenea + Cestoda was monogenean-like and most likely sanguinivorous. From this ancestral condition, adult digeneans and cestodes independently evolved dietary specialisations to suit their diverse microhabitats in their final vertebrate hosts. These improved perspectives on relationships fundamentally enhance our understanding of the evolution of parasitism in the Neodermata and in particular, the evolution of diet.     

The large (134.9 kb) mitochondrial genome of the glomeromycete <Emphasis Type="Italic">Funneliformis mosseae</Emphasis>

Funneliformis mosseae is among the most ecologically and economically important glomeromycete species and occurs both in natural and disturbed areas in a wide range of habitats and climates. In this study, we report the sequencing of the complete mitochondrial (mt) genome of F. mosseae isolate FL299 using 454 pyrosequencing and Illumina HiSeq technologies. This mt genome is a full-length circular chromosome of 134,925 bp, placing it among the largest mitochondrial DNAs (mtDNAs) in the fungal kingdom. A comparative analysis with publically available arbuscular mycorrhizal fungal mtDNAs revealed that the mtDNA of F. mosseae FL299 contained a very large number of insertions contributing to its expansion. The gene synteny was completely reshuffled compared to previously published glomeromycotan mtDNAs and several genes were oriented in an anti-sense direction. Furthermore, the presence of different types of introns and insertions in rnl (14 introns) made this gene very distinctive in Glomeromycota. The presence of alternative genetic codes in both initiation (GUG) and termination (UGA) codons was another new feature in this mtDNA compared to previously published glomeromycotan mt genomes. The phylogenetic analysis inferred from the analysis of 14 protein mt genes confirmed the position of the Glomeromycota clade as a sister group of Mortierellomycotina. This mt genome is the largest observed so far in Glomeromycota and the first mt genome within the Funneliformis clade, providing new opportunities to better understand their evolution and to develop molecular markers.     

基于太平洋甲胁虱裂化线粒体基因组推测甲胁虱属祖先线粒体核型

[目的]动物典型的单一染色体线粒体基因组在甲胁虱属Hoplopleura已裂化成多个线粒体微环染色体.本研究旨在通过测定太平洋甲胁虱Hoplopleura pacifica的线粒体基因组来推测甲胁虱属祖先线粒体核型.[方法]利用Illumina HiSeq X Ten高通量测序技术对太平洋甲胁虱裂化线粒体基因组进行测定...