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1.
J Parasitol ; 106(1): 71-81, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31995717

RESUMO

An unusual coccidian parasite was described previously from the prostate of a male Antechinus flavipes (family: Dasyuridae; common name: yellow-footed antechinus). Morphometrics and a partial nuclear 18S small subunit rDNA (18S rDNA) sequence were used to assign this parasite to the genus Eimeria; it was named Eimeria taggarti. We generated full nuclear 18S rDNA and mitochondrial genome sequences from this parasite and used the newly completed 18S rDNA and mitochondrial cytochrome c oxidase subunit I (COI) sequences to perform a more in-depth phylogenetic analysis. The parasite clustered closely with Choleoeimeria spp. and Acroeimeria spp. infecting herptiles in a well-supported clade that was the sister lineage to the Eimeriidae sensu stricto. The mitochondrial genome of this parasite contained 2 inverted segments compared to mitochondrial genomes from parasites in the Eimeriidae sensu stricto (i.e., Stieda body-possessing coccidia with 4 dizoic sporocysts); this mitochondrial genome arrangement was shared with the only Choleoeimeria species for which sequence data were available publicly. Examination of histological preparations and TEM images uncovered bivalvate sporocysts and otherwise confirmed previously described morphological features of the parasite. Based on our phylogenetic analyses and histological observations, we propose the generic reclassification of E. taggarti to Choleoeimeria taggarti n. comb.


Assuntos
Coccidiose/veterinária , Eimeriidae/genética , Genoma Mitocondrial/genética , Marsupiais/parasitologia , Próstata/parasitologia , Animais , Coccidiose/parasitologia , DNA de Protozoário/química , DNA Ribossômico/química , Eimeriidae/classificação , Eimeriidae/isolamento & purificação , Eimeriidae/ultraestrutura , Complexo IV da Cadeia de Transporte de Elétrons/genética , Masculino , Anotação de Sequência Molecular , Oocistos/ultraestrutura , Filogenia , Reação em Cadeia da Polimerase , RNA de Protozoário/genética , RNA Ribossômico 18S/genética , Alinhamento de Sequência
2.
Gene ; 725: 144161, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31639432

RESUMO

Bivalve species with doubly uniparental inheritance of mitochondria have been shown to contain additional mtDNA-encoded proteins suspected to be involved in sex-specific transmission of the female (F) and male (M) mitochondrial genomes. This is true for freshwater mussels and marine clams but was still unclear for marine mussel Mytilus spp. Here we present evidence that a F mtDNA-specific open reading frame (ORF) identified in the control region of M. edulis codes for a protein. The protein was detected, using western blots, in both female and male mantle tissues, which contain the gonads. The protein was also localized, using immunochemistry, in sperm mitochondria.


Assuntos
DNA Mitocondrial/genética , Mytilus/genética , Animais , Bivalves/genética , Feminino , Genoma Mitocondrial/genética , Masculino , Mitocôndrias/genética , Fases de Leitura Aberta/genética , Fatores Sexuais , Espermatozoides/metabolismo
3.
J Insect Sci ; 19(6)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841604

RESUMO

The family Pentatomidae, the largest within the superfamily Pentatomoidae, comprises about 5,000 species; many of which are economically important pests. Although the phylogeny of Pentatomidae species has been studied using various molecular markers, their phylogenetic relationships remain controversial. Recently, mitochondrial genomes (mitogenomes) have been extensively employed to examine the phylogenetics and evolution of different insects, and in this study, we sequenced complete/near-complete mitochondrial genomes from five shield bug species of Eurydema to gain a better understanding of phylogenetic relationships in the Pentatomidae. The five mitogenomes ranged in length from 15,500 to 16,752 bp and comprised 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a control region. We compared mitogenomic characteristics of the Pentatomidae and constructed phylogenetic trees using Bayesian inference and maximum likelihood methods. Our results showed that gene arrangements, base composition, start/stop codons, gene overlaps, and RNA structures were conserved within the Pentatomidae and that congeneric species shared more characteristics. Saturation and heterogeneity analyses revealed that our PCGs and PCGRNA datasets were valid for phylogenetic analysis. Phylogenetic analyses showed consistent topologies based on BI and ML methods. These analyses strongly supported that Eurydema species belong to the tribe Strachiini, and formed a sister group with Pentatomini. The relationships among Eurydema species were shown to be consistent with their morphological features. (Strachiini + Pentatomini) was found to be a stable sibling of the clade comprising Cappaeini, Graphosomini, and Carpocorini. Furthermore, our results indicated that Graphosoma rubrolineatum (Heteroptera: Pentatomidae) belongs to the Pentatominae and not the Podopinae.


Assuntos
Genoma Mitocondrial , Heterópteros/genética , Animais , Filogenia , Sequenciamento Completo do Genoma
4.
BMC Evol Biol ; 19(1): 217, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775623

RESUMO

BACKGROUND: Despite decades of research, the horse domestication scenario in East Asia remains poorly understood. RESULTS: The study identified 16 haplogroups with fine-scale phylogenetic resolution using mitochondrial genomes of 317 horse samples. The time to the most recent common ancestor of the 16 haplogroups ranges from [0.8-3.1] thousand years ago (KYA) to [7.9-27.1] KYA. With combined analyses of the mitochondrial control region for 35 extant Przewalski's horses, 3544 modern and 203 ancient horses across the world, researchers provide evidence for that East Asian prevalent haplogroups Q and R were indigenously domesticated or they were involved in numerous distinct genetic components from wild horses in the southern part of East Asia. These events of haplotypes Q and R occurred during 4.7 to 16.3 KYA and 2.1 to 11.5 KYA, respectively. The diffusion of preponderant European haplogroups L from west to East Asia is consistent with the external gene input. Furthermore, genetic differences were detected between northern East Asia and southern East Asia cohorts by Principal Component Analysis, Analysis of Molecular Variance test, the χ2 test and phylogeographic analyses. CONCLUSIONS: All results suggest a complex picture of horse domestication, as well as geographic pattern in East Asia. Both local origin and external input occurred in East Asia horse populations. And besides, there are at least two different domestication or hybridization centers in East Asia.


Assuntos
Cavalos/genética , Animais , DNA Mitocondrial/genética , Domesticação , Equidae/genética , Extremo Oriente , Fluxo Gênico , Variação Genética , Genoma Mitocondrial , Haplótipos , Região de Controle de Locus Gênico , Filogenia , Filogeografia , Análise de Componente Principal
5.
J Helminthol ; 94: e101, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31679533

RESUMO

Tracheophilus cymbius (Trematoda: Cyclocoelidae) is a common tracheal fluke of waterfowl, causing serious loss in the poultry industry. However, taxonomic identification of T. cymbius remains controversial and confused. Mitochondrial (mt) genomes can provide genetic markers for the identification of closely related species. We determined the mt genome of T. cymbius and reconstructed phylogenies with other trematodes. The T. cymbius mt genome is 13,760 bp in size, and contains 12 protein-coding genes (cox 1-3, nad 1-6, nad 4L, cyt b and atp 6), 22 transfer RNA (tRNA) genes, two ribosomal RNA genes and one non-coding region. All are transcribed in the same direction. The A + T content is 62.82%. ATG and TAG are the most common initiation and termination codons, respectively. Phylogenetic analyses of concatenated nucleotide sequences show T. cymbius grouping in suborder Echinostomata, and clustering together, with high statistical support, as a sister taxon with Echinochasmus japonicus (Echinochasmidae), the two forming a distinct branch rooted to the ancestor of all Echinostomatidae and Fasciolidae species. This is the first report of the T. cymbius mt genome, and the first reported mt genome within the family Cyclocoelidae. These data will provide a significant resource of molecular markers for studying the taxonomy, population genetics and systematics of trematodes.


Assuntos
Genoma Mitocondrial , Trematódeos/genética , Animais , Sequência de Bases , Genoma Helmíntico , Mitocôndrias/genética , Filogenia , Análise de Sequência de DNA , Trematódeos/classificação , Trematódeos/isolamento & purificação
6.
Yi Chuan ; 41(11): 979-993, 2019 Nov 20.
Artigo em Chinês | MEDLINE | ID: mdl-31735702

RESUMO

With rapid advances in next-generation sequencing technologies, the genomes of many organisms have been sequenced and widely applied in different settings. Mitochondrial genome data is equally important and the high-throughput whole-genome data typically contain mitochondrial genome (mitogenome) sequences. How to extract and assemble the mitogenome from massive whole-genome sequencing (WGS) data remain a hot area in molecular biology, genetics and medicine. The cataloging and analysis of accumulating mitogenome data promotes the development of assembly strategies and corresponding software applications related to mitochondrial DNA from the WGS data. Mitogenome assembly strategies can be divided into mitogenome-reference strategy and de novo strategy. Each strategy has different advantages and limitations with respect to the difference of bait mitogenome-linked short reads from the WGS data and corresponding assembly strategy. In this review, we summarize and compare current mitogenome assembly strategies and the software applications available. We also provide suggestions related to use different assembly strategies and software applications, and the expected benefits and limitations of methods references in life science.


Assuntos
Genoma Mitocondrial , Software , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Sequenciamento Completo do Genoma
7.
Zootaxa ; 4671(4): zootaxa.4671.4.8, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31716036

RESUMO

The nearly complete mitochondrial genome (mitogenome) of Leuctra sp. (Plecoptera: Leuctridae) was sequenced. The 14,585-bp long mitogenome of L. sp. contained 37 genes including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and a control region (CR). The mitochondrial gene arrangement of L. sp. was identical with other stoneflies and the putative ancestral mitogenome of Drosophila yakuba Burla. Most PCGs used standard ATN start codons and TAN termination codons. Twenty-one of the 22 tRNAs in each mitogenome exhibited the cloverleaf secondary structures, while the dihydrouridine (DHU) arm of trnSer (AGN) was reduced. Phylogenetic analyses using our new Leuctra sp. genome and all other publicly available genomes for Plecoptera and Bayesian inference (BI) and maximum likelihood methods (ML) generated identical topologies, both supporting the monophyly of all stonefly families for which tests were possible and the infraorder Systellognatha. Scopuridae and Gripopterygidae were grouped with the infraorder Euholognatha. The final relationships within Plecoptera were recovered as (((((Perlodidae + Chloroperlidae) + Perlidae) + Pteronarcyidae) + Peltoperlidae) + Styloperlidae) + (((((Capniidae + Taeniopterygidae) + Nemouridae) + Scopuridae) + Leuctridae) + Gripopterygidae).


Assuntos
Genoma Mitocondrial , Lepidópteros , Filogenia , Animais , Teorema de Bayes , Genoma de Inseto , Insetos , Lepidópteros/genética , RNA Ribossômico , RNA de Transferência
8.
Parasitol Res ; 118(12): 3253-3265, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31729573

RESUMO

Metacercariae of Clinostomum Leidy, 1856 are frequently encountered in freshwater fish. In 2015, a provisional species of Clinostomum in People's Republic of China (PRC) was distinguished from C. complanatum (Rudolphi, 1819) in Europe based on divergent cytochrome c oxidase I (CO1). However, in subsequent studies in East Asia, the same divergent CO1 genotype was identified as C. complanatum. These matching sequences suggest that either the provisional East Asian species was incorrectly distinguished from C. complanatum in 2015 or that C. complanatum in East Asia was misidentified in later studies. We tested these alternatives by sequencing the mitochondrial genome of C. complanatum in Italy, which was 5.7% divergent from a previously published sequence from Clinostomum in PRC, including differences in 80 of 3390 (2.4%) translated amino acids. Partial CO1 sequences of specimens from PRC and those from Italy, Romania, and Turkey also each formed reciprocally monophyletic clades. Partial CO1 from the East Asian clade varied by mean 3.6% (range 2.4-4.8%) from C. complanatum from Italy, Romania, and Turkey; mean intra-clade CO1 variation was 0.3% (range 0-1.9%). Metacercariae from Europe and East Asia display significant morphometric variation, and data from the literature suggest morphological differences in the genital complex of adults. Although sequences of nuclear rDNA did not differ between isolates from the west and East Asia, taken together, these results lead us to describe a new species of Clinostomum.


Assuntos
Filogenia , Trematódeos/classificação , Animais , Ásia , DNA Ribossômico/genética , Peixes/parasitologia , Água Doce/parasitologia , Genoma Mitocondrial/genética , Metacercárias/anatomia & histologia , Metacercárias/classificação , Metacercárias/genética , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
9.
Zootaxa ; 4614(3): zootaxa.4614.3.4, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31716368

RESUMO

Mitogenomes are popular sources of data in evolutionary studies. By development of next generation sequencing the number of total mitogenome in data bases rapidly increased. However, there is still a limited number of total mitogenome known from species of Tettigoniinae. This paper aims to describe the total mitogenome of Psorodonotus venosus (Orthoptera, Tettigoniidae; Tettigoniinae) obtained by NGS reads. The total mitogenome is 15836-15845 bp and consists of 13 protein coding genes (PCG), 22 tRNA genes, two rRNA genes and an AT rich control region as in other metazozans. The mitogenome is AT skewed with 69.5% AT percentage. The genes are ordered as in pancrustacean. Total length of PCGs is 11229 bp, the start codon for all fits ATN pattern and stop codons are incomplete T-- / TA- and rarely complete TAA. Total length of 22 tRNA genes is 1447 bp and their anticodons are identical to other members of Tettigonioidea. The mitogenome contains 12 overlapping regions constituting 41 bp in total. Of these 12 overlapping regions those between trnW-trnC, atp6-atp8, nad4-nad4L, nad6 -cytb and atp6-cox3 gene pairs seem to be conserved. The total length of seven noncoding intergenic spacers is 46 bp. We concluded that P. venosus is one of the species with short mitogenome amongst Tettigonioidea because of limited number and length of noncoding intergenic spacers.


Assuntos
Genoma Mitocondrial , Ortópteros , Animais , Ortópteros/genética , RNA de Transferência
10.
Zootaxa ; 4564(2): zootaxa.4564.2.10, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-31716509

RESUMO

The new species, Hilethera xinjiangensis sp. nov. (Orthoptera: Acrididae: Oedipodinae) is described based on specimens collected from Xinjiang, northern China. The new species is similar to H. brevipennis Zheng Lu, 2002 and H. turanica Uvarov, 1925, but differs from: (1) dark brown in general coloration, (2) darker coloration in forewings, (3) forewings longer than H. brevipennis but shorter than H. turanica, (4) cubital area of forewings boarder than H. brevipennis and H. turanica, (5) hind tibiae dark brown with two light yellow pre-basal rings, while dark with one fade pre-basal ring in H. brevipennis and light yellow with three dark rings in H. turanica.In addition, the complete mitogenome of holotype was sequenced using next-generation sequencing technology. The total length of the assembled mitogenome is 16,145 bp, representing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and one noncoding region (D-loop region). The new mitogenome sequence is compared with published Oedipodinae mitogenomes and the phylogenetic relationships within the subfamily are reconstructed. The results infer that the gene cox1 could be a useful marker for higher phylogenetic level, while the genes nd5 and rrnL could be potentially useful markers between closely related species.


Assuntos
Genoma Mitocondrial , Gafanhotos , Ortópteros , Animais , China , Gafanhotos/genética , Ortópteros/genética , Filogenia , RNA Ribossômico , RNA de Transferência
11.
Zootaxa ; 4652(1): zootaxa.4652.1.6, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31716886

RESUMO

In this study, the complete mitochondrial DNA sequence of Parum colligata (Lepidoptera: Sphingidae: Smerinthinae) was sequenced firstly. The mitogenome is 15,288 bp in size, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and an A+T-rich region. In the mitogenome, Ile, Leu2, and Phe are the most frequently used codon families, while codons GCG, TGC, GGC, CTG, AGG, and ACG are absent. The A+T-rich region is 358 bp in length including a motif 'ATAGA', an 18 bp poly-T stretch, three copies of a 12 bp 'TATATATATATA', and a short poly-A element. The nucleotides sequence of A+T-rich region is closer to Sphinginae than Macroglossinae. Phylogenetic analyses, based on the PCGs by using Maximum Likelihood (ML) and Bayesian Inference (BI) methods, generated consistent results that Smerinthinae was clustered together with Sphinginae to be the sister groups rather than Macroglossinae.


Assuntos
Genoma Mitocondrial , Lepidópteros , Mariposas , Animais , Teorema de Bayes , Filogenia , RNA Ribossômico , RNA de Transferência , Análise de Sequência de DNA
12.
Zootaxa ; 4651(1): zootaxa.4651.1.11, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31716929

RESUMO

Development of next generation sequencing rapidly increased the number of total mitogenome in data bases. However, the documented number of total mitogenome from species of Tettigoniinae is still limited and a comparison at subfamily level has not been made sufficiently. This paper aims to describe total mitogenome of A. babadaghi (Orthoptera, Tettigoniidae) by comparing to the known mitogenomes of other Tettigoniinae. The total mitogenome of A. babadaghi is 15882-15883 bp, AT skewed with 70.2% AT percentage, and consists of 13 protein coding genes (PCG), 22 tRNA genes, two rRNA genes and an AT rich control region. The genes are ordered as in pancrustacean. The comparative description of mitogenomes in Tettigoniinae showed that total length varies between 15766-16788 bp, the start codon for protein coding genes almost always fits to the ATN pattern, the stop codons are incomplete T-- / TA- and rarely complete TAA, intergenic spacers (IGS) and overlapping regions (OR) in species of the subfamily are similar in number, location, length and nucleotide sequence. We arrived to following conclusion from comparative data: (i) A. babadaghi has a typical orthopteran mitogenome by general features; (ii) this generalisation seems valid for Tettigoniinae as gene content, gene location, gene order, average AT content, anticodons and secondary structure of the tRNA genes, the start and stop codons of the protein coding genes, and several IGSs/ORs are similar to other orthopteran and hexapopods, (iii) variation range in total mitogenome length is narrow in Tettigoniinae and mainly determined by the lengths of control region and total IGSs, (iv) mitogenome of the subfamily exhibits conserved patterns especially in overlapping regions, but conserved features are mostly plesiomorphic.


Assuntos
Genoma Mitocondrial , Ortópteros , Animais , Sequência de Bases , Ortópteros/genética , Filogenia , RNA de Transferência
13.
Enzymes ; 45: 311-341, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31627882

RESUMO

Mitochondria play a central role in bioenergetics, and fulfill a plethora of functions in cell signaling, programmed cell death, and biosynthesis of key protein cofactors. Mitochondria harbor their own genomic DNA, which encodes protein subunits of the electron transport chain and a full set of transfer and ribosomal RNAs. Mitochondrial DNA (mtDNA) is essential for cellular and organismal functions, and defects in mitochondrial genome maintenance have been implicated in common human diseases and mitochondrial disorders. mtDNA repair and degradation are known pathways to cope with mtDNA damage; however, molecular factors involved in this process have remained unclear. Such knowledge is fundamental to the understanding of mitochondrial genomic maintenance and pathology, because mtDNA degradation may contribute to the etiology of mtDNA depletion syndromes and to the activation of the innate immune response by fragmented mtDNA. This article reviews the current literature regarding the importance of mitochondrial DNA degradation in mtDNA maintenance and stress response, and the recent progress in uncovering molecular factors involved in mtDNA degradation. These factors include key components of the mtDNA replication machinery, such as DNA polymerase γ, helicase Twinkle, and exonuclease MGME1, as well as a major DNA-packaging protein, mitochondrial transcription factor A (TFAM).


Assuntos
DNA Mitocondrial/metabolismo , Genoma Mitocondrial/genética , Estresse Fisiológico , Replicação do DNA , Humanos , Doenças Mitocondriais/genética , Doenças Mitocondriais/patologia
14.
Aquat Toxicol ; 216: 105298, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31586484

RESUMO

Organisms are routinely subjected to a variety of environmental and chemical perturbations simultaneously. Often, multi-stressor exposures result in unpredictable toxicity that occurs through unidentified mechanisms. Here, we focus on polycyclic aromatic hydrocarbons (PAHs) and hypoxia, two environmental and physiological stressors that are known to co-occur in the environment. The aim of this study was to assess whether interactive mitochondrial dysfunction resulted from co-exposures of PAHs and hypoxia. Zebrafish embryos were co-exposed to non-teratogenic concentrations of an environmental PAH mixture and hypoxia beginning at 6 hpf for an acute period of 24 h and afterwards were given either no recovery period, 45 min, 5 -hs, or 18 -hs of recovery time in clean conditions. Mitochondrial function and integrity were assessed through the use of both in ovo and in vitro assays. Hypoxia exposures resulted in drastic reductions in parameters relating to mitochondrial respiration, ATP turnover, and mitochondrial DNA integrity. PAH exposures affected ATP production and content, as well as mitochondrial membrane dynamics and lactate content. While PAH and hypoxia exposures caused a broad range of effects, there appeared to be very little interaction between the two stressors in the co-exposure group. However, because hypoxia significantly altered mitochondrial function, the possibility remains that these effects may limit an individual's ability to respond to PAH toxicity and therefore could cause downstream interactive effects.


Assuntos
Exposição Ambiental , Hipóxia/patologia , Mitocôndrias/patologia , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Área Sob a Curva , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Metabolismo Energético/efeitos dos fármacos , Genoma Mitocondrial , Ácido Láctico/metabolismo , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Peixe-Zebra/genética
15.
DNA Cell Biol ; 38(11): 1257-1268, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31553224

RESUMO

Recent analyses suggest bacterial and/or mitochondrion-like ancestry for giant viruses (Megavirales sensu latu): amoeban mitochondrial gene arrangements resemble those of their candidate homologs in megaviral genomes. This presumed ancestral synteny decreases with genome size across megaviral families at large and within Poxviridae. In this study, analyses focus on Phycodnaviridae, a polyphyletic group of giant viruses infecting Haplophyta, Stramenopiles, and other algae, using syntenies between algal mitogene arrangements and chloroplast genomes and Rickettsia prowazekii as positive controls. Mitogene alignment qualities with Rickettsia are much higher than with viral genomes. Mitogenome synteny with some viruses is higher, for others lower than with Rickettsia, despite lower alignments qualities. In some algae, syntenies among cohosted chloroplast, virus, and mitochondrion are higher, in others lower than expected. This suggests gene order coevolution in cohosted genomes, different coregulations of organelle metabolisms for different algae, and viral mitogenome mimicry, to hijack organelle-committed cellular resources and/or escape cellular defenses/genetic immunity systems. This principle might explain high synteny between human mitochondria and the pathogenic endocellular alphaproteobacterium R. prowazekii beyond common ancestry. Results indicate that putative bacteria/mitochondrion-like genomic ancestors of Phycodnaviridae originated before or at the mitochondrion-bacteria split, and ulterior functional constraints on gene arrangements of cohosted genomes.


Assuntos
Cloroplastos/genética , Evolução Molecular , Mitocôndrias/genética , Mimetismo Molecular/fisiologia , Phycodnaviridae/genética , Sintenia/genética , Imunidade Adaptativa/genética , Genoma Mitocondrial/genética , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune/genética , Organelas/genética , Filogenia , Análise de Sequência de DNA
16.
Biochemistry (Mosc) ; 84(8): 884-895, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31522670

RESUMO

DNA replication in human mitochondria has been studied for several decades; however, its mechanism still remains unclear. During the last 15 years, many new experimental data on the mitochondrial replication have appeared, although extremely contradictory. Two asynchronous (strand displacement and RITOLS) and one synchronous (strand-coupled) replication models have been proposed. In the asynchronous models, replication from the origin in the H-chain starts earlier, so that the replication of the two chains ends at different times. The synchronous model is more traditional and implies two replication forks with leading and lagging strands initiated at the same origin. For each of the three models, both confirming and contradicting experimental data exist. Most likely, there is no single model of mitochondrial replication. It is possible that the unique mitochondrial replication machinery that has originated as a results of endosymbiosis has an unexpected variety of replication strategies to maintain the mitochondrial genome. An unusual combination of enzymes of different origin (phage, bacterial, eukaryotic) and unique features of the mitochondrial genome (existance of heavy and light chains, insertions of ribonucleotides, a variety of origins) can allow replication through different mechanisms. In human mitochondria, asynchronous replication seems to dominate; however, synchronous replication is also possible under certain conditions. In the human heart mitochondria, circular mitochondrial DNA (mtDNA) molecules can rearrange in a network of rapidly replicating linear genomes, thereby suggesting possible existence of a wide range of replication mechanisms in the mitochondria. The review describes the main stages of mtDNA replication and enzymes involved in this process, as well as discusses the prospects of mitochondrial replication studies.


Assuntos
Replicação do DNA , DNA Mitocondrial/química , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Genoma Mitocondrial , Humanos , Mitocôndrias Cardíacas/metabolismo , Proteínas Mitocondriais/metabolismo , Sequências Reguladoras de Ácido Nucleico , Origem de Replicação , Fatores de Transcrição/metabolismo
17.
Parasit Vectors ; 12(1): 451, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519208

RESUMO

Ticks are obligate blood-sucking arachnid ectoparasites from the order Acarina, and many are notorious as vectors of a wide variety of zoonotic pathogens. However, the systematics of ticks in several genera is still controversial. The mitochondrial genome (mt-genome) has been widely used in arthropod phylogeny, molecular evolution and population genetics. With the development of sequencing technologies, an increasing number of tick mt-genomes have been sequenced and annotated. To date, 63 complete tick mt-genomes are available in the NCBI database, and these genomes have become an increasingly important genetic resource and source of molecular markers in phylogenetic studies of ticks in recent years. The present review summarizes all available complete mt-genomes of ticks in the NCBI database and analyses their characteristics, including structure, base composition and gene arrangement. Furthermore, a phylogenetic tree was constructed using mitochondrial protein-coding genes (PCGs) and ribosomal RNA (rRNA) genes from ticks. The results will provide important clues for deciphering new tick mt-genomes and establish a foundation for subsequent taxonomic research.


Assuntos
Genoma Mitocondrial , Mitocôndrias/genética , Carrapatos/genética , Animais , Composição de Bases , Ordem dos Genes , Filogenia
18.
Biochemistry (Mosc) ; 84(7): 817-828, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31509731

RESUMO

Natural competence of mitochondria for DNA uptake has been known for the last 20 years. Until the present time, all studies of this process have been conducted exclusively in isolated mitochondria, as no system for investigation of the DNA transport into the mitochondria in intact cells has been available. The objective of this work was to improve and standardize the existing approaches for investigating DNA import into plant mitochondria in an in organello system. A method for detecting the import of fluorescently labeled DNA substrates has been developed. Based on the features of DNA import into the mitochondria, we suggested an efficient method for the evaluation of the DNA import efficiency by quantitative PCR. We also developed and characterized the in vivo system that allows to detect DNA transport from the cytoplasm to the mitochondrial matrix in Arabidopsis thaliana protoplasts. A combination of the proposed techniques for studying the DNA uptake by plant mitochondria might be useful for elucidating whether the properties of the mitochondrial DNA import established in the in organello system are preserved in vivo.


Assuntos
Arabidopsis/metabolismo , Transporte Biológico/genética , Brassica napus/metabolismo , DNA Mitocondrial/metabolismo , Mitocôndrias/metabolismo , Zea mays/metabolismo , Genoma Mitocondrial , Genoma de Planta , Técnicas In Vitro/métodos , Proteínas Mitocondriais/genética , Células Vegetais/metabolismo , Protoplastos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Coloração e Rotulagem
19.
BMC Genomics ; 20(1): 691, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477008

RESUMO

BACKGROUND: Mitochondria perform many key roles in their eukaryotic hosts, from integrating signaling pathways through to modulating whole organism phenotypes. The > 1 billion years of nuclear and mitochondrial gene co-evolution has necessitated coordinated expression of gene products from both genomes that maintain mitochondrial, and more generally, eukaryotic cellular function. How mitochondrial DNA (mtDNA) variation modifies host fitness has proved a challenging question but has profound implications for evolutionary and medical genetics. In Drosophila, we have previously shown that recently diverged mtDNA haplotypes within-species can have more impact on organismal phenotypes than older, deeply diverged haplotypes from different species. Here, we tested the effects of mtDNA haplotype variation on gene expression in Drosophila under standardized conditions. Using the Drosophila Genetic Reference Panel (DGRP), we constructed a panel of mitonuclear genotypes that consists of factorial variation in nuclear and mtDNA genomes, with mtDNAs originating in D. melanogaster (2x haplotypes) and D. simulans (2x haplotypes). RESULTS: We show that mtDNA haplotype variation unequivocally alters nuclear gene expression in both females and males, and mitonuclear interactions are pervasive modifying factors for gene expression. There was appreciable overlap between the sexes for mtDNA-sensitive genes, and considerable transcriptional variation attributed to particular mtDNA contrasts. These genes are generally found in low-connectivity gene co-expression networks, occur in gene clusters along chromosomes, are often flanked by non-coding RNA, and are under-represented among housekeeping genes. Finally, we identify the giant (gt) transcription factor motif as a putative regulatory sequence associated with mtDNA-sensitive genes. CONCLUSIONS: There are predictive conditions for nuclear genes that are influenced by mtDNA variation.


Assuntos
Núcleo Celular/genética , Drosophila/genética , Redes Reguladoras de Genes/genética , Genoma Mitocondrial/genética , Motivos de Aminoácidos/genética , Animais , Núcleo Celular/metabolismo , Drosophila/crescimento & desenvolvimento , Feminino , Regulação da Expressão Gênica , Redes Reguladoras de Genes/fisiologia , Genes Essenciais/genética , Genes Essenciais/fisiologia , Variação Genética , Genótipo , Haplótipos , Masculino , Família Multigênica , Fenótipo , Mapas de Interação de Proteínas/genética , Mapas de Interação de Proteínas/fisiologia , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Transcriptoma
20.
Forensic Sci Int Genet ; 43: 102143, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31473588

RESUMO

Mitochondrial haplogroup information can be useful in forensic contexts that rely primarily on mitochondrial DNA (mtDNA) testing, which often involve limited or degraded DNA. Due to the phylogeographic patterning of mtDNA in human populations, mitochondrial haplogroups are indicative of maternal ancestry (as mtDNA is a maternally inherited marker). In certain circumstances, maternal ancestry inferred from mitochondrial haplogrouping could be beneficial to forensic investigations. For example, ancestry information could assist in the identification of unknown service members from past conflicts, such as the World War II Battle of Tarawa involving American and Japanese forces. In this context, it could be useful to distinguish Native American mtDNA from Asian mtDNA to bolster the anthropological and circumstantial evidence leading to an identification or foreign national determination. Although most of the founding Native American haplogroups contain diagnostic variants in the mitochondrial control region (CR), haplogroup B2 does not, and this makes it more difficult to distinguish B2 from the parental B4 and closely related B4b haplogroups found in Asia. In this paper, the amount of mtDNA information required to distinguish Native American haplotypes from Asian haplotypes within haplogroup B was examined. Fifty-six samples belonging to subtypes of B2 and B4 were sequenced for the entire mitogenome. Haplogroups were estimated from three ranges of mitochondrial DNA (HV1 and 2, CR, and full mitogenome). Half of the samples could not be precisely haplogrouped without full mitogenome data, although enough variants were often provided to make an accurate B2 versus B4 distinction. Native American B2 haplotypes were distinguishable using CR data alone in 82% of samples, though the remaining samples required full mitogenome data for haplogroup B2 designation. The use of full mitogenome data consistently enables accurate haplogroup determination, and opens the possibility for gaining information on maternal ancestry.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , DNA Mitocondrial/genética , Genoma Mitocondrial , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Índios Norte-Americanos/genética , Humanos , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
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