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1.
Parasitol Res ; 119(7): 2347-2350, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32488623

RESUMO

Thelazia callipaeda (Spirurida, Thelaziidae) is a vector-borne zoonotic eyeworm able to infect a broad spectrum of carnivores. Here, we describe the first case of bilateral infection by T. callipaeda in the eyes of an adult female Iberian wolf (Canis lupus signatus) in central Spain. Nematodes collected were morphologically identified (n = 42), and two specimens were molecularly characterized. At the sequence analysis of the partial mitochondrial cytochrome c oxidase subunit 1 gene, T. callipaeda haplotype 1 (the only haplotype circulating in Europe) was detected. The role of the Iberian wolf as a natural reservoir for T. callipaeda in the life cycle of this emerging zoonosis and the implications in conservation are discussed.


Assuntos
Olho/parasitologia , Infecções por Spirurida/veterinária , Thelazioidea/isolamento & purificação , Lobos/parasitologia , Animais , Vetores de Doenças , Complexo IV da Cadeia de Transporte de Elétrons/genética , Europa (Continente) , Feminino , Genes Mitocondriais/genética , Haplótipos/genética , Humanos , Masculino , Espanha , Thelazioidea/genética , Zoonoses/parasitologia
2.
Parasitol Res ; 119(7): 2085-2091, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32458117

RESUMO

The present study aims to perform comparative genetic characterization for R. sanguineus s.l. infesting Algerian dogs living in steppe and high plateau regions based on mitochondrial 16S rRNA gene sequencing and phylogenetic analysis. In total, 1043 ticks were collected from 147 infested dogs, including 756 ticks from 124 dogs in Djelfa and 287 ticks from 23 dogs in Bordj-Bou-Arreridj. All ticks were morphologically identified as R. sanguineus s.l., and 87 specimens were randomly selected for molecular analysis. Sequences obtained from selected ticks clustered with sequences of R. sanguineus s.l. from France, Germany, Portugal, and Spain, all of which belong to R. sanguineus s.s. The occurrence of R. sanguineus s.s. in Algeria is an interesting result given that most R. sanguineus in Africa cluster among the tropical lineage. This finding should prompt further investigation by exhaustive studies across Algerian territory. Such data can be useful to understand the dispersal route of R. sanguineus s.s. from Europe to North Africa, or whether their occurrence in Algeria is a result of historical biogeography.


Assuntos
Genes Mitocondriais/genética , Filogenia , RNA Ribossômico 16S/genética , Rhipicephalus sanguineus/classificação , Rhipicephalus sanguineus/genética , Argélia , Animais , Doenças do Cão/parasitologia , Cães , Europa (Continente)
3.
PLoS One ; 15(4): e0231009, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240264

RESUMO

Our study is focused on original and publicly accessible data on the intraspecific variability of the barcoding DNA fragment in ladybirds Harmonia axyridis Pall analysis. The complete dataset consists of 39 haplotypes, 16 of which we identified for the first time. The intra-population and geographical variability of the barcoding fragment was studied for seven populations of the western and eastern groups of the native range and in six invasive populations, in which 25 of the 39 haplotypes are found. Population structure inferred on base of molecular variability and haplotype frequencies showed a high level of differences between the eastern and western groups of native populations and confirm the hypothesis of the origin of all invasive populations from native populations of the eastern group. A comparative analysis of molecular variation indices testifies to various evolutionary scenarios of the formation of the western and eastern groups of native populations and confirms the hypothesis of the microevolutionary history of the species, previously suggested in morphological character based studies of the geographical variability of H. axyridis. A significant decrease in the molecular diversity of invasive populations confirms the hypothesis of a random nature of the primary invasion of this species in North America.


Assuntos
Besouros/genética , Genes Mitocondriais/genética , Variação Genética/genética , Animais , Evolução Biológica , Genética Populacional/métodos , Haplótipos/genética , Espécies Introduzidas , América do Norte
4.
Mitochondrial DNA A DNA Mapp Seq Anal ; 31(3): 98-107, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32186219

RESUMO

South China presents an excellent opportunity to build a phylogeographic paradigm for complex geological history, including mountain lifting, climate change, and river capture/reversal events. The phylogeography of cyprinids, particularly Opsariichthys hainanensis, an endemic species restricted to South China, was examined to explore the relationship between the populations in Red River, Hainan Island and its adjacent mainland China. A total of 37 haplotypes were genotyped for the mitochondrial cytochrome b (Cyt b) gene in 115 specimens from 11 river systems. Relatively high levels of haplotype diversity (h = 0.946) and low levels of nucleotide diversity (π = 0.014) were detected in O. hainanensis. Four major phylogenetic haplotype groups revealed a relationship between phylogeny and geography. Our results found that (i) the ancestral populations of O. hainanensis were distributed south of the Wuzhishan and Yinggeling mountains, including the Changhua River on Hainan Island, and then spread to the surrounding areas, (ii) the admixtures within lineages occurred between the Red River in North Vietnam and the Changhua River in western Hainan Island and (iii) indicated that the exposure of straits and shelves under water retreat, provides opportunities for population dispersion during glaciations.


Assuntos
Cyprinidae/genética , Citocromos b/genética , Animais , China , DNA Mitocondrial/genética , Peixes/genética , Genes Mitocondriais/genética , Estruturas Genéticas/genética , Variação Genética/genética , Genética Populacional/métodos , Genoma Mitocondrial/genética , Haplótipos/genética , Mitocôndrias/genética , Filogenia , Filogeografia , Rios , Análise de Sequência de DNA/métodos
5.
Artigo em Inglês | MEDLINE | ID: mdl-32202175

RESUMO

In this paper, we investigate the genetic structure and phylogeography of Rhinolophus ferrumequinum, using the mitochondrial cytochrome b gene (1017 bp) in Iran and adjacent regions. The total haplotype and nucleotide diversity are 0.63 ± 0.055 and 0.0021 ± 0.00017, respectively which suggest that R. ferrumequinum exhibits low genetic diversity. AMOVA analysis shows that more variation of genetic differentiation is present among populations of phylogenetic groupings than within populations. Our phylogenetic results support the monophyly of R. ferrumequinum and suggest this taxon comprises three allopatric/parapatric phylogroups that are distributed in Europe-western Turkey, eastern Turkey-northern Iran, and southern Iran. The Europe-western Turkey lineage (clade 2) split from the eastern Turkey-Iran lineage (clade 1) during the middle Pleistocene (0.8534 (ca.I)-0.6454 (ca.II) Ma). The divergence time among subclades A and B occurred during the mid-Pleistocene (0.4849 (ca.I)-0.369 (ca.II) Ma). All phylogenetic analyses also indicate that the Iranian and eastern Turkey R. ferrumequinum diverged from Europe and western Turkey R. ferrumequinum, with the mean percentage sequence differences ranging from 0.92%-0.75% between them. We infer that long-term isolation of R. ferrumequinum in spatially distinct refugia in parts of southwestern and northeastern Iran has promoted distinct phylogeographic lineages during the Pleistocene.


Assuntos
Quirópteros/genética , Citocromos b/genética , Animais , Evolução Biológica , DNA Mitocondrial/genética , Evolução Molecular , Genes Mitocondriais/genética , Variação Genética/genética , Genética Populacional/métodos , Genoma Mitocondrial/genética , Haplótipos/genética , Irã (Geográfico) , Mitocôndrias/genética , Filogenia , Filogeografia/métodos , Análise de Sequência de DNA/métodos , Turquia
6.
Mitochondrial DNA A DNA Mapp Seq Anal ; 31(3): 120-130, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32212876

RESUMO

To understand the genetic diversity and dispersal history of Schlegel's Japanese gecko (Gekko japonicus), we performed genetic analyses and paleo-species distributional modelling. For the genetic analysis, we analyzed mitochondrial DNA (mtDNA) (cytochrome b [Cytb] and NADH dehydrogenase 2 [ND2]) and seven microsatellite loci of 353 individuals from 11 populations (2 east coast China, 4 west and central coast Japan and 5 Korea). For the paleo-species distribution modelling, we used 432 occurrence data points (125 China, 291 Japan and 16 Korea) over the Pleistocene and Holocene. China is inferred to be the source population, which had higher genetic diversity (mtDNA) and more private alleles (mtDNA) compared to Japanese and Korean populations. Differences between the three counties were very small in the mtDNA haplotype network despite some genetic structure among the three countries. Microsatellite analysis inferred that genetic exchange has actively occurred among the Chinese, Japanese and Korean populations. Suitable habitats in Japan should have been plentiful by the mid-Holocene, but have only recently become available in Korea. These results suggest that dispersal of G. japonicus occurred after the Holocene warming from the east coast of China to the west and central coasts of Japan and Korea, and gene flow is actively occurring among the three countries.


Assuntos
Citocromos b/genética , Lagartos/genética , NADH Desidrogenase/genética , Alelos , Animais , China , DNA Mitocondrial/genética , Ecossistema , Genes Mitocondriais/genética , Variação Genética/genética , Genética Populacional/métodos , Genoma Mitocondrial/genética , Haplótipos/genética , Japão , Repetições de Microssatélites/genética , Mitocôndrias/genética , Filogenia , Filogeografia/métodos , República da Coreia , Análise de Sequência de DNA/métodos
7.
J Fish Biol ; 96(6): 1360-1369, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32112652

RESUMO

Limia islai, a new species of livebearing fish, is described from Lake Miragoane in south-western Haiti on Hispaniola. The new species has a conspicuous barred pattern consisting of several (4-12) black bars along the body, ray 4p serrae of the gonopodium in males with 10 segments and origin of dorsal fin in females slightly behind the origin of the anal fin. Although the new species colour pattern is similar to that of the humpbacked limia Limia nigrofasciata Regan 1913, L. islai sp. nov. has exclusive morphological features, such as slender body, lack of hump anterior to dorsal fin in males and presence of specific features in the gonopodial suspensory, which allow an unambiguous diagnosis from L. nigrofasciata. L. islai further differs from L. nigrofasciata in reproductive behaviour since L. islai males rely on sneak copulations and gonopodial thrusting, whereas L. nigrofasciata display an elaborate courtship behaviour. The new species is also genetically distinct in both nuclear (Rh, Myh6) and mitochondrial (12S, ND2, D-loop, Cytb) genes from other species in the genus showing reciprocal monophyly. The description of this new Limia species from Lake Miragoane confirms this lake as an important centre of endemism for the genus, with a total of eight endemic species described so far.


Assuntos
Ciprinodontiformes/classificação , Nadadeiras de Animais/anatomia & histologia , Animais , Ciprinodontiformes/anatomia & histologia , Ciprinodontiformes/genética , Feminino , Proteínas de Peixes/genética , Genes Mitocondriais/genética , Haiti , Lagos , Masculino , Pigmentação , Comportamento Sexual Animal , Especificidade da Espécie
8.
Parasitol Res ; 119(2): 763-770, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31863181

RESUMO

Cystic echinococcosis is a disease that affects both humans and animals, caused by cryptic species complex belonging to the platyhelminth Echinococcus granulosus sensu lato (s.l.). This disease is distributed worldwide, with E. granulosus sensu stricto (s.s.) being the most widespread of the species. High genetic variability has been demonstrated within E. granulosus s.s. studying single cyst per infected animal identifying a number of different haplotypes. However, few studies have addressed the genetic diversity of this parasite within a single intermediate host with multiple Echinococcus cysts. To date, it remains unknown if specific haplotypes of E. granulosus s.s. produce differences in biological features of the cyst. Here, we use the full length of the mitochondrial gene cox1 to determine E. granulosus s.s. haplotypes in samples from both cattle and sheep which harboured more than one cyst in different areas in Chile, where this parasite is endemic. We found 16 different haplotypes in 66 echinococcal cysts from 10 animals, and both cattle and sheep can harbour up to five different haplotypes of E. granulosus s.s. in the same animal. Regarding cyst fertility, five animals had both fertile and infertile Echinococcus cysts in both single and multiple haplotype infections. There was no association between haplotype and cyst fertility, size, or adventitial layer characteristics. Sampling and sequencing every Echinococcus cyst found in the intermediate host reveals a high molecular variability. We speculate that multiple haplotype infections could also suggest that intermediate hosts come from hyperendemic areas.


Assuntos
Doenças dos Bovinos/parasitologia , Equinococose/veterinária , Echinococcus granulosus/classificação , Doenças dos Ovinos/parasitologia , Animais , Bovinos , Chile , Ciclo-Oxigenase 1/genética , Equinococose/parasitologia , Echinococcus granulosus/genética , Echinococcus granulosus/isolamento & purificação , Fertilidade , Genes Mitocondriais/genética , Variação Genética/genética , Genótipo , Haplótipos , Humanos , Ovinos/genética
9.
J Genet ; 982019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31767814

RESUMO

Andaman buffalo is an indigenous buffalo of Andaman and Nicobar Islands, India. Over the last decade, it has witnessed a rapid decline in population, necessitating its immediate characterization and conservation. The present study reports the complete mitogenome profile of Andaman buffalo which is 16,359 bp in length and comprised of 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs and two ribosomal RNAs. In addition, one A + T rich region (D-loop) was also present. A biasness towards A and T base was observed in all the genes. All the PCGs except ND6 were present on heavy strand. Start codons for all the 13 PCGs were ATN codon and abbreviated/truncated stop codons were observed in ND1, ND2, COX3, ND3 and ND4. The phylogenetic analysis revealed that the Andaman buffalo is closely related to buffalo from India and China. The results from this study will help in sketching the conservation plan of the threatened breed.


Assuntos
Búfalos/genética , Genes Mitocondriais/genética , Genoma Mitocondrial/genética , Mitocôndrias/genética , Animais , Composição de Bases , China , Códon de Iniciação , Códon de Terminação , Genes de RNAr/genética , Sequenciamento de Nucleotídeos em Larga Escala , Índia , Conformação de Ácido Nucleico , Filogenia , RNA Ribossômico/genética , RNA de Transferência/genética , Alinhamento de Sequência , Análise de Sequência de DNA
10.
Nat Commun ; 10(1): 4589, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31597917

RESUMO

The urothelium is an epithelial barrier lining the bladder that protects against infection, fluid exchange and damage from toxins. The nuclear receptor Pparg promotes urothelial differentiation in vitro, and Pparg mutations are associated with bladder cancer. However, the function of Pparg in the healthy urothelium is unknown. Here we show that Pparg is critical in urothelial cells for mitochondrial biogenesis, cellular differentiation and regulation of inflammation in response to urinary tract infection (UTI). Superficial cells, which are critical for maintaining the urothelial barrier, fail to mature in Pparg mutants and basal cells undergo squamous-like differentiation. Pparg mutants display persistent inflammation after UTI, and Nf-KB, which is transiently activated in response to infection in the wild type urothelium, persists for months. Our observations suggest that in addition to its known roles in adipogegnesis and macrophage differentiation, that Pparg-dependent transcription plays a role in the urothelium controlling mitochondrial function development and regeneration.


Assuntos
Diferenciação Celular , Células Epiteliais/metabolismo , Expressão Gênica , Genes Mitocondriais/genética , PPAR gama/metabolismo , Urotélio/metabolismo , Animais , Humanos , Inflamação/complicações , Inflamação/genética , Camundongos Knockout , Camundongos Transgênicos , Mutação , PPAR gama/genética , Bexiga Urinária/citologia , Neoplasias da Bexiga Urinária/genética , Infecções Urinárias/complicações , Urotélio/citologia
11.
PLoS One ; 14(10): e0224373, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31661528

RESUMO

Decapod crustaceans, such as alvinocaridid shrimps, bythograeid crabs and galatheid squat lobsters are important fauna in the hydrothermal vents and have well adapted to hydrothermal vent environments. In this study, eighteen mitochondrial genomes (mitogenomes) of hydrothermal vent decapods were used to explore the evolutionary history and their adaptation to the hydrothermal vent habitats. BI and ML algorithms produced consistent phylogeny for Decapoda. The phylogenetic relationship revealed more evolved positions for all the hydrothermal vent groups, indicating they migrated from non-vent environments, instead of the remnants of ancient hydrothermal vent species, which support the extinction/repopulation hypothesis. The divergence time estimation on the Alvinocarididae, Bythograeidae and Galatheoidea nodes are located at 75.20, 56.44 and 47.41-50.43 Ma, respectively, which refers to the Late Cretaceous origin of alvinocaridid shrimps and the Early Tertiary origin of bythograeid crabs and galatheid squat lobsters. These origin stories are thought to associate with the global deep-water anoxic/dysoxic events. Total eleven positively selected sites were detected in the mitochondrial OXPHOS genes of three lineages of hydrothermal vent decapods, suggesting a link between hydrothermal vent adaption and OXPHOS molecular biology in decapods. This study adds to the understanding of the link between mitogenome evolution and ecological adaptation to hydrothermal vent habitats in decapods.


Assuntos
Adaptação Fisiológica/genética , Decápodes/genética , Genes Mitocondriais/genética , Aclimatação , Animais , Evolução Biológica , Decápodes/metabolismo , Ecossistema , Evolução Molecular , Variação Genética/genética , Genoma Mitocondrial/genética , Fontes Hidrotermais , Filogenia
12.
PLoS One ; 14(10): e0224501, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31661532

RESUMO

Cystic echinococcosis (CE) is a worldwide zoonotic disease caused by the larval stage of Echinococcus granulosus. We investigated the presence of E. granulosus-specific DNA in the serum of CE patients by detecting the cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit I (nad1) mitochondrial genes. Serum and formalin-fixed paraffin embedded (FFPE) cyst tissue samples of 80 CE patients were analyzed. The extracted DNA of samples was submitted to PCR amplification of cox1 and nad1 genes, and products were sequenced and genotyped. Nineteen (23.8%; 95% CI 15.8-34.1) serum and 78 (97.5%; 95% CI 91.3-99.3) FFPE cyst tissue samples were successfully amplified with at least one gene. Echinococcus DNA was detected in the sera of 15.0% (95% CI: 8.8-24.4) and 10.0% (95% CI: 5.2-18.5) and in cyst tissue of 91.3% (95% CI: 83.0-95.7) and 83.8% (95% CI: 74.2-90.3) of 80 patients by cox1 and nad1 gene, respectively. Four genotypes of E. granulosus were distinguished in the CE patients, with predominance of genotype G1, followed by G3, G2, and G6. The finding of E. granulosus DNA in 23.8% of serum samples from CE patients confirmed that E. granulosus releases cell-free DNA into the circulatory system, but quantities may be inadequate for the diagnosis of CE. Genotype G1 predominance suggests the sheep-dog cycle as the primary route of human infection.


Assuntos
DNA Mitocondrial/genética , Equinococose/diagnóstico , Echinococcus granulosus/genética , Adolescente , Adulto , Idoso , Animais , Sequência de Bases , Criança , Ciclo-Oxigenase 1/genética , Cistos/genética , Equinococose/sangue , Equinococose/genética , Echinococcus/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Formaldeído , Genes Mitocondriais/genética , Variação Genética/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , NADH Desidrogenase/genética , Inclusão em Parafina , Reação em Cadeia da Polimerase
13.
Adv Exp Med Biol ; 1158: 247-255, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31452144

RESUMO

The maternally inherited mitochondrial DNA (mtDNA) is located inside every mitochondrion, in variable number of copies, and it contains 37 crucial genes for cellular bioenergetics. This chapter will discuss the unique features of this circular genome including heteroplasmy, haplogroups, among others, along with the corresponding clinical relevance for each. The discussion also covers the nuclear-encoded mitochondrial genes (N > 1000) and the epistatic interactions between mtDNA and the nuclear genome. Examples of mitochondrial diseases related to specific mtDNA mutation sites of relevance for humans are provided. This chapter aims to provide an overview of mitochondrial genetics as an emerging hot topic for the future of medicine.


Assuntos
Metabolismo Energético , Mitocôndrias , DNA Mitocondrial/genética , Metabolismo Energético/genética , Epistasia Genética , Genes Mitocondriais/genética , Genoma/genética , Humanos , Mitocôndrias/genética , Doenças Mitocondriais/genética , Mutação
14.
Vet Parasitol ; 271: 76-79, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31303209

RESUMO

The equine Parascaris spp. is large, parasitic nematodes, and predominantly focuses on the intestine of foals and young weanlings. There are two roundworms, Parascaris equorum and Parascaris univalens, recognized among equine hosts. In this study, all fifty-nine Parascaris worms were harvested from three different equine hosts (twenty specimens from Equus zebra, twenty specimens from E. caballus, and nineteen specimens from E. asinus). The ribosomal gene (ITS) and mitochondrial genes (cox1 and nadh1) were amplified to identify and genetically characterize these worms. Analysis of ITS sequences revealed five genotypes among the fifty-nine worms, and the sequence similarity among the worms from E. zebra and E. caballus was at a high level (99.87%), while the one of E. asinus worms showed an apparent difference from the worms either from the E. zebra or from the E. caballus (sequence similarity ranging from 93.04 to 93.42%). Analysis of mitochondrial genes revealed that twenty-one (cox1 gene) and thirteen (nadh1 gene) unique haplotypes were defined among the fifty-nine worms. The shared haplotypes (four cox1 haplotypes and one nadh1 haplotype) only occurred between the worm populations from E. zebra and E. caballus. The cox1 and nadh1 haplotype sequences were respectively applied to construct phylogenetic trees. Although the topologies showed that E. asinus worm population had an obvious boundary with the worm populations of the E. zebra and the E. caballus, however, no noticeable boundary was found within the two later worm populations. Meanwhile, the E. asinus worm population showed an obvious genetic differentiation and an extremely low gene flow (close to zero) with the worm populations from E. zebra and E. caballus, indicating that the genetic characteristics of the worms from the E. asinus have an obvious difference with the one from E. zebra and E. caballus.


Assuntos
Ascaridoidea/classificação , Ascaridoidea/genética , Equidae/parasitologia , Cavalos/parasitologia , Filogenia , Animais , DNA Espaçador Ribossômico/genética , Genes Mitocondriais/genética
15.
Cells ; 8(7)2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31248014

RESUMO

After billions of years of evolution, mitochondrion retains its own genome, which gets expressed in mitochondrial matrix. Mitochondrial translation machinery rather differs from modern bacterial and eukaryotic cytosolic systems. Any disturbance in mitochondrial translation drastically impairs mitochondrial function. In budding yeast Saccharomyces cerevisiae, deletion of the gene coding for mitochondrial translation initiation factor 3 - AIM23, leads to an imbalance in mitochondrial protein synthesis and significantly delays growth after shifting from fermentable to non-fermentable carbon sources. Molecular mechanism underlying this adaptation to respiratory growth was unknown. Here, we demonstrate that slow adaptation from glycolysis to respiration in the absence of Aim23p is accompanied by a gradual increase of cytochrome c oxidase activity and by increased levels of Tma19p protein, which protects mitochondria from oxidative stress.


Assuntos
Adaptação Fisiológica , Fatores de Iniciação em Eucariotos/genética , Mitocôndrias/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Deleção de Genes , Regulação Fúngica da Expressão Gênica/fisiologia , Genes Mitocondriais/genética , Glicólise/fisiologia , Mitocôndrias/genética , Estresse Oxidativo/fisiologia , Biossíntese de Proteínas/fisiologia
16.
Genet Med ; 21(12): 2823-2826, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31171843

RESUMO

PURPOSE: A recent report has raised the possibility of biparental mitochondrial DNA (mtDNA) inheritance, which could lead to concerns by health-care professionals and patients regarding investigations and genetic counseling of families with pathogenic mitochondrial DNA variants. Our aim was to examine the frequency of this phenomenon by investigating a cohort of patients with suspected mitochondrial disease. METHODS: We studied genome sequencing (GS) data of DNA extracted from blood samples of 41 pediatric patients with suspected mitochondrial disease and their parents. RESULTS: All of the mtDNA variants in the probands segregated with their mother or were apparently de novo. There were no variants that segregated only with the father and none of these families showed evidence of biparental inheritance of their mtDNA. CONCLUSION: Paternal mitochondrial transmission is unlikely to be a common occurrence and therefore at this point we would not recommend changes in clinical practice.


Assuntos
DNA Mitocondrial/genética , Herança Materna/genética , Doenças Mitocondriais/genética , Adulto , Sequência de Bases/genética , Criança , Pré-Escolar , Pai , Feminino , Genes Mitocondriais/genética , Hereditariedade , Humanos , Masculino , Mitocôndrias/genética , Doenças Mitocondriais/sangue , Mães
17.
Nucleic Acids Res ; 47(13): 6858-6870, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31194871

RESUMO

Inverted repeats are common DNA elements, but they rarely overlap with protein-coding sequences due to the ensuing conflict with the structure and function of the encoded protein. We discovered numerous perfect inverted repeats of considerable length (up to 284 bp) embedded within the protein-coding genes in mitochondrial genomes of four Nematomorpha species. Strikingly, both arms of the inverted repeats encode conserved regions of the amino acid sequence. We confirmed enzymatic activity of the respiratory complex I encoded by inverted repeat-containing genes. The nucleotide composition of inverted repeats suggests strong selection at the amino acid level in these regions. We conclude that the inverted repeat-containing genes are transcribed and translated into functional proteins. The survey of available mitochondrial genomes reveals that several other organisms possess similar albeit shorter embedded repeats. Mitochondrial genomes of Nematomorpha demonstrate an extraordinary evolutionary compromise where protein function and stringent secondary structure elements within the coding regions are preserved simultaneously.


Assuntos
Genes de Helmintos/genética , Genes Mitocondriais/genética , Código Genético , Genoma Mitocondrial , Helmintos/genética , Sequências Repetidas Invertidas/genética , Sequência de Aminoácidos , Animais , Composição de Bases , Sequência de Bases , DNA de Helmintos/genética , DNA Ribossômico/genética , Complexo I de Transporte de Elétrons/genética , Evolução Molecular , Feminino , Proteínas de Helminto/genética , Masculino , Consumo de Oxigênio , RNA de Helmintos/genética , RNA Ribossômico 18S/genética , Seleção Genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
18.
Integr Comp Biol ; 59(4): 875-889, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31225591

RESUMO

Maternal inheritance of mitochondrial DNA (mtDNA) renders selection blind to mutations whose effects are limited to males. Evolutionary theory predicts this will lead to the accumulation of a male-specific genetic load within the mitochondrial genomes of populations; that is, a pool of mutations that negatively affects male, but not female, fitness components. This principle has been termed the Mother's Curse hypothesis. While the hypothesis has received some empirical support, its relevance to natural populations of metazoans remains unclear, and these ambiguities are compounded by the lack of a clear predictive framework for studies attempting to test Mother's Curse. Here, we seek to redress this by outlining the core predictions of the hypothesis, as well as the key features of the experimental designs that are required to enable direct testing of the predictions. Our goal is to provide a roadmap for future research seeking to elucidate the evolutionary significance of the Mother's Curse hypothesis.


Assuntos
Evolução Biológica , Núcleo Celular/genética , Genes Mitocondriais/genética , Herança Materna/genética , Animais , DNA Mitocondrial/genética , Feminino , Masculino , Modelos Genéticos
19.
Nucleic Acids Res ; 47(14): 7502-7517, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31226201

RESUMO

Maintenance of mitochondrial gene expression is crucial for cellular homeostasis. Stress conditions may lead to a temporary reduction of mitochondrial genome copy number, raising the risk of insufficient expression of mitochondrial encoded genes. Little is known how compensatory mechanisms operate to maintain proper mitochondrial transcripts levels upon disturbed transcription and which proteins are involved in them. Here we performed a quantitative proteomic screen to search for proteins that sustain expression of mtDNA under stress conditions. Analysis of stress-induced changes of the human mitochondrial proteome led to the identification of several proteins with poorly defined functions among which we focused on C6orf203, which we named MTRES1 (Mitochondrial Transcription Rescue Factor 1). We found that the level of MTRES1 is elevated in cells under stress and we show that this upregulation of MTRES1 prevents mitochondrial transcript loss under perturbed mitochondrial gene expression. This protective effect depends on the RNA binding activity of MTRES1. Functional analysis revealed that MTRES1 associates with mitochondrial RNA polymerase POLRMT and acts by increasing mitochondrial transcription, without changing the stability of mitochondrial RNAs. We propose that MTRES1 is an example of a protein that protects the cell from mitochondrial RNA loss during stress.


Assuntos
Perfilação da Expressão Gênica , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteômica/métodos , Proteínas de Ligação a RNA/metabolismo , Transcrição Genética/genética , Sequência de Aminoácidos , Genes Mitocondriais/genética , Células HEK293 , Células HeLa , Humanos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteoma/genética , Proteoma/metabolismo , RNA Mitocondrial/genética , Proteínas de Ligação a RNA/genética , Homologia de Sequência de Aminoácidos , Estresse Fisiológico
20.
Nucleic Acids Res ; 47(14): 7648-7665, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31251801

RESUMO

Mitochondria are essential molecular machinery for the maintenance of cellular energy supply by the oxidative phosphorylation system (OXPHOS). Mitochondrial transcription factor B1 (TFB1M) is a dimethyltransferase that maintains mitochondrial homeostasis by catalyzing dimethylation of two adjacent adenines located in helix45 (h45) of 12S rRNA. This m62A modification is indispensable for the assembly and maturation of human mitochondrial ribosomes. However, both the mechanism of TFB1M catalysis and the precise function of TFB1M in mitochondrial homeostasis are unknown. Here we report the crystal structures of a ternary complex of human (hs) TFB1M-h45-S-adenosyl-methionine and a binary complex hsTFB1M-h45. The structures revealed a distinct mode of hsTFB1M interaction with its rRNA substrate and with the initial enzymatic state involved in m62A modification. The suppression of hsTFB1M protein level or the overexpression of inactive hsTFB1M mutants resulted in decreased ATP production and reduced expression of components of the mitochondrial OXPHOS without affecting transcription of the corresponding genes and their localization to the mitochondria. Therefore, hsTFB1M regulated the translation of mitochondrial genes rather than their transcription via m62A modification in h45.


Assuntos
Proteínas de Ligação a DNA/genética , Genes Mitocondriais/genética , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Biossíntese de Proteínas , RNA Ribossômico/genética , Fatores de Transcrição/genética , Sequência de Bases , Cristalografia por Raios X , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Homeostase/genética , Humanos , Metilação , Mitocôndrias/metabolismo , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Ribossomos Mitocondriais/metabolismo , Mutação , Fosforilação Oxidativa , Ligação Proteica , RNA Ribossômico/química , RNA Ribossômico/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
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