Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Genome Res ; 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35501131

RESUMO

Y Chromosomes of many species are gene poor and show low levels of nucleotide variation, yet often display high amounts of structural diversity. Dobzhansky cataloged several morphologically distinct Y Chromosomes in Drosophila pseudoobscura that differ in size and shape, but the molecular causes of their dramatic size differences are unclear. Here we use cytogenetics and long-read sequencing to study the sequence content of polymorphic Y Chromosomes in D. pseudoobscura We show that Y Chromosomes differ almost 2-fold in size, ranging from 30 to 60 Mb. Most of this size difference is caused by a handful of active transposable elements (TEs) that have recently expanded on the largest Y Chromosome, with different elements being responsible for Y expansion on differently sized D. pseudoobscura Y's. We show that Y Chromosomes differ in their heterochromatin enrichment, expression of Y-enriched TEs, and also influence expression of dozens of autosomal and X-linked genes. The same helitron element that showed the most drastic amplification on the largest Y in D. pseudoobscura independently amplified on a polymorphic large Y Chromosome in D. affinis, suggesting that some TEs are inherently more prone to become deregulated on Y Chromosomes.

2.
J Med Virol ; 94(5): 1959-1966, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34964514

RESUMO

PURPOSE: Since the pandemic of coronavirus disease-19 (COVID-19), the incidence of influenza has decreased significantly, but there are still few reports in the short period before and after the pandemic period. This study aimed to explore influenza activity and dynamic changes before and during the pandemic. METHODS: A total of 1 324 357 influenza-like illness (ILI) cases were reported under the ILI surveillance network from January 1, 2018, to September 5, 2021, in Nanjing, of which 16 158 cases were detected in a laboratory. Differences in ILI and influenza were conducted with the χ2 test. RESULTS: The number of ILI cases accounted for 8.97% of outpatient and emergency department visits. The influenza-positive ratio (IPR) was 7.84% in ILI cases. During the COVID-19 pandemic, ILI% and IPR dropped by 6.03% and 11.83% on average, respectively. Besides this, IPR rose slightly in Week 30-35 of 2021. Not only differences in gender, age, and employment status, but also the circulating strains had changed from type A to B through the COVID-19 pandemic. CONCLUSION: The level of influenza activity was severely affected by COVID-19, but it seems that it is inevitable to be vigilant against the co-circulation in the future.


Assuntos
COVID-19 , Influenza Humana , COVID-19/epidemiologia , China/epidemiologia , Humanos , Incidência , Influenza Humana/epidemiologia , Pandemias , Viroses/epidemiologia
3.
Nanomaterials (Basel) ; 11(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443929

RESUMO

The nanostructures of ionic liquids (ILs) have been the focus of considerable research attention in recent years. Nevertheless, the nanoscale structures of ILs in the presence of polymers have not been described in detail at present. In this study, nanostructures of ILs disturbed by poly(vinylidene fluoride) (PVdF) were investigated via high-pressure infrared spectra. For 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([HEMIm][TFSI])-PVdF mixtures, non-monotonic frequency shifts of the C4,5-H vibrations upon dilution were observed under ambient pressure. The experimental results suggest the presence of microheterogeneity in the [HEMIm][TFSI] systems. Upon compression, PVdF further influenced the local structure of C4,5-H via pressure-enhanced IL-PVdF interactions; however, the local structures of C2-H and hydrogen-bonded O-H were not affected by PVdF under high pressures. For choline [TFSI]-PVdF mixtures, PVdF may disturb the local structures of hydrogen-bonded O-H. In the absence of the C4,5-H⋯anion and C2-H⋯anion in choline [TFSI]-PVdF mixtures, the O-H group becomes a favorable moiety for pressure-enhanced IL-PVdF interactions. Our results indicate the potential of high-pressure application for designing pressure-dependent electronic switches based on the possible changes in the microheterogeneity and electrical conductivity in IL-PVdF systems under various pressures.

5.
J Mater Chem B ; 9(26): 5318-5328, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34231629

RESUMO

For cancer treatment, the traditional monotherapy has the problems of low drug utilization rate, poor efficacy and easy recurrence of the cancer. Herein, nanoparticles (NPs) based on a novel semiconducting molecule (ITTC) are developed with excellent photostability, high photothermal conversion efficiency and good 1O2 generation ability. The chemotherapy of the hypoxia-activated prodrug tirapazamine (TPZ) was improved accordingly after oxygen consumption by the photodynamic therapy of ITTC NPs. Additionally, the metabolic process of ITTC NPs in vivo could be monitored in real time for fluorescence imaging guided phototherapy, which presented great passive targeting ability to the tumor site. Remarkably, both in vitro and in vivo experiments demonstrated that the combination of ITTC NPs and TPZ presented excellent synergistic tumor ablation through photothermal therapy, photodynamic therapy and hypoxia-activated chemotherapy with great potential for clinical applications in the future.


Assuntos
Antineoplásicos/farmacologia , Hipóxia/diagnóstico por imagem , Hipóxia/tratamento farmacológico , Nanopartículas/química , Imagem Óptica , Fármacos Fotossensibilizantes/farmacologia , Tirapazamina/farmacologia , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Nanopartículas/administração & dosagem , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/tratamento farmacológico , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/química , Semicondutores , Tirapazamina/administração & dosagem , Tirapazamina/química
6.
J Vis Exp ; (172)2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34152322

RESUMO

Chromatin immunoprecipitation sequencing (ChIP-seq) is a powerful and widely used molecular technique for mapping whole genome locations of transcription factors (TFs), chromatin regulators, and histone modifications, as well as detecting entire genomes for uncovering TF binding patterns and histone posttranslational modifications. Chromatin-modifying activities, such as histone methylation, are often recruited to specific gene regulatory sequences, causing localized changes in chromatin structures and resulting in specific transcriptional effects. The rice blast is a devastating fungal disease on rice throughout the world and is a model system for studying fungus-plant interaction. However, the molecular mechanisms in how the histone modifications regulate their virulence genes in Magnaporthe oryzae remain elusive. More researchers need to use ChIP-seq to study how histone epigenetic modification regulates their target genes. ChIP-seq is also widely used to study the interaction between protein and DNA in animals and plants, but it is less used in the field of plant pathology and has not been well developed. In this paper, we describe the experimental process and operation method of ChIP-seq to identify the genome-wide distribution of histone methylation (such as H3K4me3) that binds to the functional target genes in M. oryzae. Here, we present a protocol to analyze the genome-wide distribution of histone modifications, which can identify new target genes in the pathogenesis of M. oryzae and other filamentous fungi.


Assuntos
Ascomicetos , Sequenciamento de Cromatina por Imunoprecipitação , Animais , Ascomicetos/genética , Cromatina , Código das Histonas/genética , Processamento de Proteína Pós-Traducional
7.
Mol Plant Pathol ; 22(4): 422-439, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33559339

RESUMO

Histone-3-lysine-4 (H3K4) methylation is catalysed by the multiprotein complex known as the Set1/COMPASS or MLL/COMPASS-like complex, an element that is highly evolutionarily conserved from yeast to humans. However, the components and mechanisms by which the COMPASS-like complex targets the H3K4 methylation of plant-pathogenic genes in fungi remain elusive. Here we present a comprehensive analysis combining biochemical, molecular, and genome-wide approaches to characterize the roles of the COMPASS-like family in the rice blast fungus Magnaporthe oryzae, a model plant pathogen. We purified and identified six conserved subunits of COMPASS from M. oryzae: MoBre2 (Cps60/ASH2L), MoSpp1 (Cps40/Cfp1), MoSwd2 (Cps35), MoSdc1 (Cps25/DPY30), MoSet1 (MLL/ALL), and MoRbBP5 (Cps50), using an affinity tag on MoBre2. We determined the sequence repeat in dual-specificity kinase splA and ryanodine receptors domain of MoBre2 can interact directly with the DPY30 domain of MoSdc1 in vitro. Furthermore, we found that deletion of the genes encoding COMPASS subunits of MoBre2, MoSPP1, and MoSwd2 caused similar defects regarding invasive hyphal development and pathogenicity. Genome-wide profiling of H3K4me3 revealed that it has remarkable co-occupancy at the transcription start site regions of target genes. Significantly, these target genes are often involved in spore germination and pathogenesis. Decreased gene expression caused by the deletion of MoBre2, MoSwd2, or MoSpp1 was highly correlated with a decrease in H3K4me3. These results suggest that MoBre2, MoSpp1, and MoSwd2 function as a whole COMPASS complex, contributing to fungal development and pathogenesis by regulating H3K4me3-targeted genes in M. oryzae.


Assuntos
Ascomicetos/genética , Proteínas Fúngicas/metabolismo , Histonas/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/patogenicidade , Proteínas Fúngicas/genética , Expressão Gênica , Regulação Fúngica da Expressão Gênica , Histonas/genética , Hifas , Metilação , Esporos Fúngicos
8.
Prep Biochem Biotechnol ; 51(8): 821-831, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33346692

RESUMO

In this study, polyphenols from olive leaves was extracted by ultrasound-assisted aqueous two phase extraction (UAATPE). Based on single factor experiment and response surface methodology (RSM), the optimum extraction conditions of polyphenols contained 29% (w/w) (NH4)2SO4, 35% (w/w) ethanol, pH 6.7, and 45 °C. The maximum extraction yield of polyphenols and oleuropein content were 34.06 mg/g and 44.13 mg/L, respectively. Compared with ultrasound-assisted extraction (UAE) and aqueous two phase extraction (ATPE), the extraction yield of polyphenols by UAATPE was 9.48 and 61.19% higher, respectively. In addition, the extract of UAATPE had higher purity. The results of antioxidant activity showed that polyphenols extracted by UAATPE had stronger DPPH and hydroxyl radicals scavenging ability and reducing power. Therefore, UAATPE is an efficient method for extracting polyphenols from olive leaves.


Assuntos
Olea/química , Folhas de Planta/química , Polifenóis , Ondas Ultrassônicas , Polifenóis/química , Polifenóis/isolamento & purificação
9.
Des Monomers Polym ; 23(1): 141-154, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33029082

RESUMO

Polynorbornenes, prepared by the 'living' and 'controlled' ring-opening metathesis polymerization (ROMP) method, have emerged as a stimuli-sensitive new class of polymer carriers. Herein, we reported a novel amphiphilic diblock polynorbornene, PNCHO-b-PNTEG, containing active benzaldehyde units, which exhibited good conjugating capacity to amino-containing molecules (e.g., doxorubicin (DOX)) via the pH-sensitive Schiff base linkage. The copolymer and its conjugate with DOX, DOX-PNCHO-b-PNTEG, were adequately analyzed by various techniques including 1H NMR, 13C NMR, gel permeation chromatography, etc. Especially, the formed conjugate of DOX-PNCHO-b-PNTEG could self-assemble into near-spherical micelles with the diameter of 81 ± 10 nm, and exhibit acid-triggered DOX release behavior, and the release rate could be adjusted by changing the environmental pH value. The excellent biological safety of PNCHO-b-PNTEG was further demonstrated by the results from both in vitro toxicity evaluation to murine fibroblast cells (L-929 cells) and in vivo evaluation of acute developmental toxicity and cell death in zebrafish embryos. Hence, the present polynorbornene-based PNCHO-b-PNTEG possesses great potential application as a biocompatible polymeric carrier and could be employed to fabricate various pH-sensitive conjugates.

10.
Carbohydr Polym ; 248: 116783, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919571

RESUMO

To optimize the extraction of polysaccharides from Notopterygium franchetii Boiss (NFP), microwave-assisted aqueous two phase system (MAATPS) and response surface methodology (RSM) were employed. Results showed that the optimum conditions of MAATPS were as follows: ethanol concentration of 32 % (w/w), (NH4)2SO4 concentration of 24 % (w/w) and extraction time of 15 min. Under such condition, YS (the recovery of polysaccharides) was 80.57 % with 90.40 % of YP (the recovery of proteins). In addition, analysis of the physicochemical properties of extracted polysaccharides (NFP-MAATPS) under the optimal conditions indicated that compared to polysaccharides extracted by traditional extraction method (NFP-HWE), NFP-MAATPS exhibited higher extraction efficiency, decreased average molecular weight, different monosaccharide compositions and mole ratios. Moreover, NFP-MAATPS exhibited stronger antioxidant activity in vitro and more potent anti-inflammatory activity in zebrafish embryos than NFP-HWE. Our results suggest that purified NFP-MAATPS could be potentially used in complementary medicines or functional foods.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Apiaceae/química , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/embriologia , Sequestradores de Radicais Livres/farmacologia , Larva/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química , Polissacarídeos/isolamento & purificação , Peixe-Zebra/embriologia
11.
ACS Appl Mater Interfaces ; 12(35): 39764-39771, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32658444

RESUMO

Graphene has demonstrated great promise for technological use, yet control over material growth and understanding of how material imperfections affect the performance of devices are challenges that hamper the development of applications. In this work, we reveal new insight into the connections between the performance of the graphene devices as environmental sensors and the microscopic details of the interactions at the sensing surface. We monitor changes in the resistance of the chemical-vapor deposition grown graphene devices as exposed to different concentrations of ethanol. We perform thermal surface treatments after the devices are fabricated, use scanning probe microscopy to visualize their effects down to nanometer scale and correlate them with the measured performance of the device as an ethanol sensor. Our observations are compared to theoretical calculations of charge transfers between molecules and the graphene surface. We find that, although often overlooked, the surface cleanliness after device fabrication is responsible for the device performance and reliability. These results further our understanding of the mechanisms of sensing in graphene-based environmental sensors and pave the way to optimizing such devices, especially for their miniaturization, as with decreasing size of the active zone the potential role of contaminants will rise.

12.
Front Microbiol ; 11: 1215, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32582119

RESUMO

Tuberculosis (TB), one of the ancient and deadliest diseases, is a chronic immune disorder caused by Mycobacterium tuberculosis (Mtb) infection. Due to the lack of ideal diagnostic and therapeutic markers, TB is still posing a major health, social, and economic burden worldwide. Circular RNA (circRNA), a newly discovered endogenous RNA, is abundant and stable in the cytoplasm and has tissue specificity. More and more studies suggested circRNA is involved in a variety of human pathological and physiological processes. Recently, several studies have confirmed circRNAs not only existed in the serum but also could serve as ideal biomarkers for detecting diseases since the circRNAs have continuous, stable, and covalently closed circular structures and are not easily degraded by nucleases. In this study, we screened the circRNA expression profiles in active TB serum samples and healthy volunteers serum samples by circRNA microarrays. Then, we performed qRT-PCR to verified the dysregulated circRNAs and ROC curve analysis to evaluate the value of circRNAs for TB diagnosis. The results showed circRNA_051239, circRNA_029965, and circRNA_404022 could serve as biomarkers for TB diagnosis.

14.
Carbohydr Polym ; 221: 73-83, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31227169

RESUMO

A protein-containing polysaccharide, LCP, showing strong antioxidant activity from the rhizome of Ligusticum chuanxiong Hort was fractionated and purified. Its physicochemical properties were characterised by gel permeation chromatography (GPC), gas chromatography-mass spectrometry (GC-MS), UV and IR analysis. The results showed that LCP was proteoglycan containing 85.7% total carbohydrate, 2.79% protein, 5.14% uronic acid, and four kinds of monosaccharides including xylose, glucose, mannose and galactose with molar ratios of 1.2: 7.8: 1: 2.1, respectively. The average molecular weight of LCP was 15.8 × 104 Da. In addition, the results indicated that LCP exhibited good radical scavenging abilities. Furthermore, LCP partially attenuated the incidence of mortalities and pericardial edema in zebrafish embryos exposed to hydrogen peroxide (H2O2). Moreover, LCP provided protection against H2O2-induced ROS generation and cell death in zebrafish embryo. These results indicated that LCP could be a potential approach for oxidative stress damage reversal.


Assuntos
Sequestradores de Radicais Livres/farmacologia , Ligusticum/química , Polissacarídeos/farmacologia , Animais , Desenvolvimento Embrionário/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/toxicidade , Peróxido de Hidrogênio/farmacologia , Peso Molecular , Estresse Oxidativo/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Rizoma/química , Peixe-Zebra/embriologia
15.
Chemosphere ; 233: 336-346, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31176896

RESUMO

6-benzylaminopurine (6-BA) is widely used in agriculture and horticulture as plant growth regulator. Its excessive use may pose a potential risk to both environment and human health, which is causing great concern. This study was undertaken to assess the acute developmental toxicity of 6-BA to zebrafish embryos based on OECD protocols and mortality, hatching rate and malformation were investigated. Results showed that the 96 h-LC50 and 96 h- EC50 values were 63.29 mg/L and 41.86 mg/L, respectively. No mortality or teratogenic effects were found at concentrations lower than 10 mg/L 6-BA at concentrations higher than 50 mg/L significantly inhibited hatchability and embryo development, induced serious toxicity characterized by morphologic abnormalities (elongated pericardium, heart and yolk sac edema, spine curvature) and functional failure (slow spontaneous movement and heart rate, growth retardation, yolk sac absorption retention). Moreover, 6-BA-induced apoptosis was observed in embryos by the acridine orange staining and confirmed by the apoptotic-related genes, all of which p53 was significantly up-regulated at concentrations higher than 10 mg/L, bax at concentrations higher than 12.5 mg/L, while bcl2 was down-regulated at concentrations higher than 25 mg/L. As for genes of cardiac development, qPCR results demonstrated that nkx2.5, gata5, and amhc were significantly down-regulated at concentrations higher than 25 mg/L, vmhc and atp2a2a at concentration of 50 mg/L, in contrast, hand2 was up-regulated at concentration of 50 mg/L. Our data indicate that 6-BA induces a dose-dependent toxicity resulting in apoptosis through the involvement of p53-dependent pathways and hindering normal heart development in zebrafish embryos.


Assuntos
Compostos de Benzil/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Purinas/toxicidade , Peixe-Zebra/embriologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Compostos de Benzil/administração & dosagem , Relação Dose-Resposta a Droga , Embrião não Mamífero/patologia , Feminino , Humanos , Masculino , Purinas/administração & dosagem , Testes de Toxicidade Aguda
16.
Clin Chim Acta ; 486: 275-281, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30125535

RESUMO

OBJECTIVE: A key step in the evaluation of the accuracy of blood glucose monitoring systems (BGMS) is using a comparator method aligned to a high order definitive reference method. We describe how we achieved traceability to an isotope dilution liquid chromatography mass spectrometry (ID-LCMS) method. We used ID-LCMS to evaluate the accuracy and specificity of two hospital BGMS used in China. METHOD: ID-LCMS was used to verify the calibration alignment of the laboratory plasma hexokinase reference method using NIST standard reference material and clinical samples. The ID-LCMS aligned hexokinase method was used to evaluate the clinical accuracy of two BGMS in hospitalized patients. System accuracy was evaluated using Chinese consensus guidelines. BGMS accuracy was also assessed with interference factors known to be present in critically ill patients' blood. RESULTS: The laboratory plasma hexokinase reference method was shown to calibrate closely with ID-LCMS. Two BGMS demonstrated good correlation with this reference method. Only one BGMS met the Chinese guidelines. The interference factors didn't influence this BGMS but adversely affected the clinical accuracy of the other. CONCLUSIONS: We advocate that our IDMS calibration alignment approach for ensuring the accuracy of the glucose reference method should be adopted in evaluations assessing the accuracy of blood glucose monitoring systems.


Assuntos
Automonitorização da Glicemia/normas , Glicemia/análise , Calibragem , Cromatografia Líquida/normas , Hexoquinase/sangue , Hexoquinase/metabolismo , Humanos , Espectrometria de Massas/normas , Técnica de Diluição de Radioisótopos/normas , Padrões de Referência
17.
J Vis Exp ; (138)2018 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-30124637

RESUMO

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current measures to combat such pathogens have proved too conservative and, thus, not sufficiently effective, and they can potentially pose environmental risks. Therefore, it is extremely necessary to identify host-resistance factors to assist in controlling plant diseases naturally through the identification of resistant germplasm, the isolation and characterization of resistance genes, and the molecular breeding of resistant cultivars. In this regard, there is need to establish an accurate, rapid, and large-scale inoculation method to breed and develop plant resistance genes. The rice blast fungal pathogen Magnaporthe grisea causes severe disease symptoms and yield losses. Recently, M. grisea has emerged as a model organism for studying the mechanisms of plant-fungal pathogen interactions. Hence, we report the development of a plant virulence test method that is specific for M. grisea. This method provides for both spray inoculation with a conidial suspension and wounding inoculation with mycelium cubes or droplets of conidial suspension. The key step of the wounding inoculation method for detached rice leaves is to make wounds on plant leaves, which avoids any interference caused by host penetration resistance. This spray/wounding protocol contributes to the rapid, accurate, and large-scale screening of the pathotypes of M. grisea isolates. This integrated and systematic plant infection method will serve as an excellent starting point for gaining a broad perspective of issues in plant pathology.


Assuntos
Genes de Plantas/genética , Magnaporthe/patogenicidade , Doenças das Plantas/microbiologia
18.
New Phytol ; 215(4): 1503-1515, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28722229

RESUMO

A major resistance quantitative trait locus, qRfg1, significantly enhances maize resistance to Gibberella stalk rot, a devastating disease caused by Fusarium graminearum. However, the underlying molecular mechanism remains unknown. We adopted a map-based cloning approach to identify the resistance gene at qRfg1 and examined the dynamic epigenetic changes during qRfg1-mediated maize resistance to the disease. A CCT domain-containing gene, ZmCCT, is the causal gene at the qRfg1 locus and a polymorphic CACTA-like transposable element (TE1) c. 2.4 kb upstream of ZmCCT is the genetic determinant of allelic variation. The non-TE1 ZmCCT allele is in a poised state, with predictive bivalent chromatin enriched for both repressive (H3K27me3/H3K9me3) and active (H3K4me3) histone marks. Upon pathogen challenge, this non-TE1 ZmCCT allele was promptly induced by a rapid yet transient reduction in H3K27me3/H3K9me3 and a progressive decrease in H3K4me3, leading to disease resistance. However, TE1 insertion in ZmCCT caused selective depletion of H3K4me3 and enrichment of methylated GC to suppress the pathogen-induced ZmCCT expression, resulting in disease susceptibility. Moreover, ZmCCT-mediated resistance to Gibberella stalk rot is not affected by photoperiod sensitivity. This chromatin-based regulatory mechanism enables ZmCCT to be more precise and timely in defense against F. graminearum infection.


Assuntos
Elementos de DNA Transponíveis/genética , Resistência à Doença/genética , Epigênese Genética , Gibberella/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Zea mays/genética , Zea mays/microbiologia , Alelos , Metilação de DNA/genética , Regulação da Expressão Gênica de Plantas , Histonas/metabolismo , Fotoperíodo , Mapeamento Físico do Cromossomo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Locos de Características Quantitativas/genética , Plântula/genética
19.
Biomed Res Int ; 2016: 1575430, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27747223

RESUMO

Ash1 is a known H3K36-specific histone demethylase that is required for normal Hox gene expression and fertility in Drosophila and mammals. However, little is known about the expression and function of the fungal ortholog of Ash1 in phytopathogenic fungus Magnaporthe oryzae. Here we report that MoKMT2H, an Ash1-like protein, is required for conidium germination and virulence in rice. We obtained MoKMT2H null mutant (ΔMoKMT2H) using a target gene replacement strategy. In the ΔMoKMT2H null mutants, global histone methyltransferase modifications (H3K4me3, H3K9me3, H3K27me3, and H3K36me2/3) of the genome were unaffected. The ΔMoKMT2H mutants showed no defect in vegetative hyphal growth, conidium morphology, conidiation, or disease lesion formation on rice leaves. However, the MoKMT2H deletion mutants were delayed for conidium germination and consequently had decreased virulence. Taken together, our results indicated that MoKMT2H plays an important role in conidium germination during appressorium formation in the rice blast fungus and perhaps other pathogenic plant fungi.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Magnaporthe/fisiologia , Mutação , Esporos Fúngicos/fisiologia , Deleção de Genes , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Ácidos Nucleicos/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Esporos Fúngicos/genética , Virulência
20.
PLoS One ; 10(8): e0135836, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26284361

RESUMO

Human dynactin-associated protein (dynAP) is a transmembrane protein that promotes AktSer473 phosphorylation. Here, we report the oncogenic properties of dynAP. In contrast to control NIH3T3 cells expressing LacZ (NIH3T3LacZ), NIH3T3dynAP cells vigorously formed foci in two-dimensional culture, colonies on soft agar, and spheroids in anchorage-deficient three-dimensional culture. NIH3T3dynAP cells injected into nude mice produced tumors with abundant blood vessels and weak cell-cell contacts. Expression of dynAP elevated the level of rictor (an essential subunit of mTORC2) and promoted phosphorylation of FOXO3aSer253. FOXO3a is a transcriptional factor that stimulates expression of pro-apoptotic genes and phosphorylation of FOXO3a abrogates its function, resulting in promoted cell survival. Knockdown of rictor in NIH3T3dynAP cells reduced AktSer473 phosphorylation and formation of foci, colony in soft agar and spheroid, indicating that dynAP-induced activation of the mTORC2/AktSer473 pathway for cell survival contributes to cell transformation. E-cadherin and its mRNA were markedly reduced upon expression of dynAP, giving rise to cells with higher motility, which may be responsible for the weak cell-cell adhesion in tumors. Thus, dynAP could be a new oncoprotein and a target for cancer therapy.


Assuntos
Comunicação Celular , Transformação Celular Neoplásica , Proteínas Associadas aos Microtúbulos/genética , Neoplasias/irrigação sanguínea , Neoplasias/patologia , Neovascularização Patológica/genética , Animais , Complexo Dinactina , Feminino , Humanos , Óperon Lac/genética , Camundongos , Células NIH 3T3 , Neoplasias/genética , Regulação para Cima
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...