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1.
Cell ; 159(6): 1341-51, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25467443

RESUMO

Intraspecific genetic incompatibilities prevent the assembly of specific alleles into single genotypes and influence genome- and species-wide patterns of sequence variation. A common incompatibility in plants is hybrid necrosis, characterized by autoimmune responses due to epistatic interactions between natural genetic variants. By systematically testing thousands of F1 hybrids of Arabidopsis thaliana strains, we identified a small number of incompatibility hot spots in the genome, often in regions densely populated by nucleotide-binding domain and leucine-rich repeat (NLR) immune receptor genes. In several cases, these immune receptor loci interact with each other, suggestive of conflict within the immune system. A particularly dangerous locus is a highly variable cluster of NLR genes, DM2, which causes multiple independent incompatibilities with genes that encode a range of biochemical functions, including NLRs. Our findings suggest that deleterious interactions of immune receptors limit the combinations of favorable disease resistance alleles accessible to plant genomes.


Assuntos
Arabidopsis/genética , Arabidopsis/imunologia , Epistasia Genética , Sequência de Aminoácidos , Arabidopsis/classificação , Cruzamentos Genéticos , Genoma de Planta , Hibridização Genética , Dados de Sequência Molecular , Filogenia , Fenômenos Fisiológicos Vegetais , Alinhamento de Sequência
2.
Small ; : e2402543, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39077961

RESUMO

Area-selective deposition (ASD) based on self-aligned technology has emerged as a promising solution for resolving misalignment issues during ultrafine patterning processes. Despite its potential, the problems of area-selectivity losing beyond a certain thickness remain critical in ASD applications. This study reports a novel approach to sustain the area-selectivity of Ir films as the thickness increases. Ir films are deposited on Al2O3 as the growth area and SiO2 as the non-growth area using atomic-layer-deposition with tricarbonyl-(1,2,3-η)-1,2,3-tri(tert-butyl)-cyclopropenyl-iridium and O3. O3 exhibits a dual effect, facilitating both deposition and etching. In the steady-state growth regime, O3 solely contributes to deposition, whereas in the initial growth stages, longer exposure to O3 etches the initially formed isolated Ir nuclei through the formation of volatile IrO3. Importantly, longer O3 exposure is required for the initial etching on the growth area(Al2O3) compared to the non-growth area(SiO2). By controlling the O3 injection time, the area selectivity is sustained even above a thickness of 25 nm by suppressing nucleation on the non-growth area. These findings shed light on the fundamental mechanisms of ASD using O3 and offer a promising avenue for advancing thin-film technologies. Furthermore, this approach holds promise for extending ASD to other metals susceptible to forming volatile species.

3.
Plant J ; 109(1): 144-163, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34724278

RESUMO

Radish, Raphanus sativus L., is an important root crop that is cultivated worldwide. Owing to its evolutionary proximity to Arabidopsis thaliana, radish can be used as a model root crop in research on the molecular basis of agronomic traits. Pithiness is a significant defect that reduces the production of radish with commercial value; however, traditional breeding to eliminate this trait has thus far been unsuccessful. Here, we performed transcriptomics and genotype-by-sequencing (GBS)-based quantitative trait locus (QTL) analyses of radish inbred lines to understand the molecular basis of pithiness in radish roots. The transcriptome data indicated that pithiness likely stems from the response to oxidative stress, leading to cell death of the xylem parenchyma during the root-thickening process. Subsequently, we narrowed down a list of candidates responsible for pithiness near a major QTL and found polymorphisms in a radish homologue of Arabidopsis ANAC013 (RsNAC013), an endoplasmic reticulum bound NAC transcription factor that is targeted to the nucleus to mediate the mitochondrial retrograde signal. We analysed the effects of polymorphisms in RsNAC013 using Arabidopsis transgenic lines overexpressing RsNAC013 alleles as well as in radish inbred lines bearing these alleles. This analysis indicated that non-synonymous variations within the coding sequence result in different levels of RsNAC013 activities, thereby providing a genetic condition for root pithiness. The elevated oxidative stress or hypoxia that activates RsNAC013 for mitochondrial signalling enhances this process. Collectively, this study serves as an exemplary case of translational research taking advantage of the extensive information available from a model organism.


Assuntos
Apoptose/genética , Locos de Características Quantitativas/genética , Raphanus/genética , Fatores de Transcrição/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Estresse Oxidativo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Raphanus/fisiologia , Fatores de Transcrição/genética
4.
NMR Biomed ; 36(3): e4862, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36308279

RESUMO

The oligomeric amyloid-ß (oAß) is a reliable feature for an early diagnosis of Alzheimer's disease (AD). Therefore, the objective of this study was to demonstrate imaging of oAß deposits using our developed DNA aptamer called ob5 conjugated with gadolinium (Gd)-dodecane tetraacetic acid (DOTA) as a contrast agent for early diagnosis of AD using MRI. An oAß-specific aptamer was developed by amide bond formation and conjugated to Gd-DOTA MRI contrast agent and/or cyanine5 (cy5). We verified the performance of our new contrast agent with an AD mouse model using in vivo and ex vivo fluorescent imaging and animal MRI experiments. The presence of soluble Aß in 3xTg AD mice was detected using GdDOTA-ob5-cy5 probe ex vivo. Fluorescence intensities of the GdDOTA-ob5-cy5 contrast agent were high in the brains of 3xTg-AD mice, but relatively low in the brains of control mice. The GdDOTA-ob5 contrast agent had higher relaxivity than a clinically available contrast agent. T1-weighted MRI signals in 5-month-old 3xTg AD mice increased at 5 min, were prolonged until 10 min, then decreased 15 min after injecting the GdDOTA-ob5 contrast agent. Our targeted DNA aptamer GdDOTA-ob5 contrast agent could be potentially useful for validating the efficacy of a novel diagnostic contrast agent for selectively targeting neurotoxic oAß. It could ultimately be used for early diagnosis of AD.


Assuntos
Doença de Alzheimer , Aptâmeros de Nucleotídeos , Camundongos , Animais , Doença de Alzheimer/diagnóstico por imagem , Meios de Contraste/química , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Imageamento por Ressonância Magnética/métodos , Modelos Animais de Doenças , Camundongos Transgênicos
5.
Nature ; 548(7668): 413-419, 2017 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-28783728

RESUMO

Genome editing has potential for the targeted correction of germline mutations. Here we describe the correction of the heterozygous MYBPC3 mutation in human preimplantation embryos with precise CRISPR-Cas9-based targeting accuracy and high homology-directed repair efficiency by activating an endogenous, germline-specific DNA repair response. Induced double-strand breaks (DSBs) at the mutant paternal allele were predominantly repaired using the homologous wild-type maternal gene instead of a synthetic DNA template. By modulating the cell cycle stage at which the DSB was induced, we were able to avoid mosaicism in cleaving embryos and achieve a high yield of homozygous embryos carrying the wild-type MYBPC3 gene without evidence of off-target mutations. The efficiency, accuracy and safety of the approach presented suggest that it has potential to be used for the correction of heritable mutations in human embryos by complementing preimplantation genetic diagnosis. However, much remains to be considered before clinical applications, including the reproducibility of the technique with other heterozygous mutations.


Assuntos
Proteínas de Transporte/genética , Embrião de Mamíferos/metabolismo , Edição de Genes/métodos , Mutação/genética , Adulto , Alelos , Blastocisto/metabolismo , Blastocisto/patologia , Divisão Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Quebras de DNA de Cadeia Dupla , Embrião de Mamíferos/patologia , Marcação de Genes , Teste de Complementação Genética , Heterozigoto , Homozigoto , Humanos , Masculino , Mosaicismo , Reparo de DNA por Recombinação/genética , Fase S , Moldes Genéticos , Zigoto/metabolismo , Zigoto/patologia
6.
Regul Toxicol Pharmacol ; 145: 105519, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37866701

RESUMO

Formaldehyde has been classified as carcinogenic to humans by International Agency for Research on Cancer and found in personal care (PC) products containing formaldehyde-donor (FD) preservatives. However, the cancer risk associated with the use of FD-containing PC products has not been well established. Our study provides the quantitative cancer risk assessment of formaldehyde in FD-containing PC products. The carbon-13 nuclear magnetic resonance (13C-NMR) spectroscopy was used in this risk assessment to provide reliable exposure information to formaldehyde in PC products and aqueous solutions containing sodium hydroxymethylglycinate. The risk assessment was conducted using the margin of exposure (MOE) approach with benchmark doses (BMDs) for 10% effect. For hemolymphoreticular neoplasias in male rats, a BMD of 28.03 mg/kg/day and a BMD lower confidence limit (BMDL) of 2.52 mg/kg/day were calculated from available long-term animal experiments. The worst-case consumer exposure to formaldehyde from FD-containing PC products was 0.007 µg/kg/day. Comparing the consumer exposure with BMDL, the resulting MOE was 360,000 for the worst-case scenario. The consumer exposure to formaldehyde (0.007 µg/kg/day) from using FD-containing PC products represents less than 1.0 × 10-6 % of background level endogenous formaldehyde (878-1310 mg/kg/day). The cancer risk from formaldehyde to consumers using FD-containing PC products is negligible.


Assuntos
Cosméticos , Neoplasias , Humanos , Masculino , Ratos , Animais , Cosméticos/toxicidade , Cosméticos/química , Formaldeído/toxicidade , Conservantes Farmacêuticos , Carcinógenos , Medição de Risco
7.
Ann Bot ; 130(1): 41-52, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35460565

RESUMO

BACKGROUND AND AIMS: Ongoing global warming is a challenge for humankind. A series of drastic climatic changes have been proven to have occurred throughout the Cenozoic based on a variety of geological evidence, which helps to better understand our planet's future climate. Notably, extant biomes have recorded drastic environmental shifts. The climate in southern Asia, which hosts high biodiversity, is deeply impacted by the Asian monsoon. The origins and evolutionary dynamics of biomes occurring between the tropics and sub-tropics in southern Asia have probably been deeply impacted by climatic changes; however, these aspects remain poorly studied. We tested whether the evolutionary dynamics of the above biomes have recorded the drastic, late Cenozoic environmental shifts, by focusing on Magnolia section Michelia of the family Magnoliaceae. METHODS: We established a fine time-calibrated phylogeny of M. section Michelia based on complete plastid genomes and inferred its ancestral ranges. Finally, we estimated the evolutionary dynamics of this section through time, determining its diversification rate and the dispersal events that occurred between tropical and sub-tropical areas. KEY RESULTS: The tropical origin of M. section Michelia was dated to the late Oligocene; however, the diversification of its core group (i.e. M. section Michelia subsection Michelia) has occurred mainly from the late Miocene onward. Two key evolutionary shifts (dated approx. 8 and approx. 3 million years ago, respectively) were identified, each of them probably in response to drastic climatic changes. CONCLUSION: Here, we inferred the underlying evolutionary dynamics of biomes in southern Asia, which probably reflect late Cenozoic climatic changes. The occurrence of modern Asian monsoons was probably fundamental for the origin of M. section Michelia; moreover, the occurrence of asymmetric dispersal events between the tropics and sub-tropics hint at an adaptation strategy of M. section Michelia to global cooling, in agreement with the tropical conservatism hypothesis.


Assuntos
Magnolia , Magnoliaceae , Biodiversidade , Mudança Climática , Filogenia
8.
PLoS Genet ; 15(7): e1008313, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31344025

RESUMO

In many plant species, conflicts between divergent elements of the immune system, especially nucleotide-binding oligomerization domain-like receptors (NLR), can lead to hybrid necrosis. Here, we report deleterious allele-specific interactions between an NLR and a non-NLR gene cluster, resulting in not one, but multiple hybrid necrosis cases in Arabidopsis thaliana. The NLR cluster is RESISTANCE TO PERONOSPORA PARASITICA 7 (RPP7), which can confer strain-specific resistance to oomycetes. The non-NLR cluster is RESISTANCE TO POWDERY MILDEW 8 (RPW8) / HOMOLOG OF RPW8 (HR), which can confer broad-spectrum resistance to both fungi and oomycetes. RPW8/HR proteins contain at the N-terminus a potential transmembrane domain, followed by a specific coiled-coil (CC) domain that is similar to a domain found in pore-forming toxins MLKL and HET-S from mammals and fungi. C-terminal to the CC domain is a variable number of 21- or 14-amino acid repeats, reminiscent of regulatory 21-amino acid repeats in fungal HET-S. The number of repeats in different RPW8/HR proteins along with the sequence of a short C-terminal tail predicts their ability to activate immunity in combination with specific RPP7 partners. Whether a larger or smaller number of repeats is more dangerous depends on the specific RPW8/HR autoimmune risk variant.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Ascomicetos/patogenicidade , Resistência à Doença , Imunidade Inata , Doenças das Plantas/microbiologia , Sequências Repetitivas de Ácido Nucleico
9.
Int J Mol Sci ; 23(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36293082

RESUMO

HVA22 family proteins with a conserved TB2/DP1/HVA22 domain are ubiquitous in eukaryotes. HVA22 family genes have been identified in a variety of plant species. However, there has been no comprehensive genome-wide analysis of HVA22 family genes in tomato (Solanum lycopersicum L.). Here, we identified 15 non-redundant SlHVA22 genes with three segmentally duplicated gene pairs on 8 of the 12 tomato chromosomes. The predicted three-dimensional (3D) models and gene ontology (GO) annotations of SlHVA22 proteins pointed to their putative transporter activity and ability to bind to diverse ligands. The co-expression of SlHVA22 genes with various genes implicated in multiple metabolic pathways and the localization of SlHVA22-GFP fused proteins to the endoplasmic reticulum suggested that they might have a variety of biological functions, including vesicular transport in stressed cells. Comprehensive expression analysis revealed that SlHVA22 genes were differentially expressed in various organs and in response to abiotic stress conditions. The predominant expression of SlHVA22i at the ripening stage and that of SlHVA22g, SlHVA22k, and SlHVA22l in fruits at most developmental stages suggested their probable involvement in tomato fruit development and ripening. Moreover, the transcript expression of most tomato HVA22 genes, particularly SlHVA22b, SlHVA22i, SlHVA22k, SlHVA22l, SlHVA22m, and SlHVA22n, was affected by abscisic acid (ABA) and diverse abiotic stress treatments, indicating the likely involvement of these genes in tomato abiotic stress responses in an ABA-dependent manner. Overall, our findings provide a foundation to better understand the structures and functional roles of SlHVA22 genes, many of which might be useful to improve the abiotic stress tolerance and fruit quality of tomato through marker-assisted backcrossing or transgenic approaches.


Assuntos
Solanum lycopersicum , Solanum lycopersicum/metabolismo , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética , Genoma de Planta , Família Multigênica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Perfilação da Expressão Gênica , Filogenia
10.
Nat Methods ; 15(8): 591-594, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30013048

RESUMO

We describe Strelka2 ( https://github.com/Illumina/strelka ), an open-source small-variant-calling method for research and clinical germline and somatic sequencing applications. Strelka2 introduces a novel mixture-model-based estimation of insertion/deletion error parameters from each sample, an efficient tiered haplotype-modeling strategy, and a normal sample contamination model to improve liquid tumor analysis. For both germline and somatic calling, Strelka2 substantially outperformed the current leading tools in terms of both variant-calling accuracy and computing cost.


Assuntos
Variação Genética , Mutação em Linhagem Germinativa , Software , Bases de Dados Genéticas/estatística & dados numéricos , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Humanos , Mutação INDEL , Modelos Genéticos , Neoplasias/genética , Sequenciamento Completo do Genoma/estatística & dados numéricos
11.
Nat Methods ; 15(7): 554, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29899368

RESUMO

In the version of this article initially published, the authors erroneously reported the search mode that was used for ProSightPC 3.0 in the Online Methods and in Supplementary Table 3.

12.
New Phytol ; 229(3): 1215-1233, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32970825

RESUMO

Autoimmunity in plants has been found in numerous hybrids as a form of hybrid necrosis and mutant panels. Uncontrolled cell death is a main cellular outcome of autoimmunity, which negatively impacts growth. Its occurrence highlights the vulnerable nature of the plant immune system. Genetic investigation of autoimmunity in hybrid plants revealed that extreme variation in the immune receptor repertoire is a major contributor, reflecting an evolutionary conundrum that plants face in nature. In this review, we discuss natural variation in the plant immune system and its contribution to fitness. The value of autoimmunity genetics lies in its ability to identify combinations of a natural immune receptor and its partner that are predisposed to triggering autoimmunity. The network of immune components for autoimmunity becomes instrumental in revealing mechanistic details of how immune receptors recognize cellular invasion and activate signaling. The list of autoimmunity-risk variants also allows us to infer evolutionary processes contributing to their maintenance in the natural population. Our approach to autoimmunity, which integrates mechanistic understanding and evolutionary genetics, has the potential to serve as a prognosis tool to optimize immunity in crops.


Assuntos
Autoimunidade , Imunidade Vegetal , Autoimunidade/genética , Evolução Biológica , Imunidade Vegetal/genética , Plantas/genética , Transdução de Sinais
13.
Metabolomics ; 17(4): 36, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33738589

RESUMO

INTRODUCTION: Chemotherapy is a major etiology of cachexia. Ginseng products are known to have various anti-cachectic and health-promoting effects, such as inhibiting inflammation and promoting energy production. In particular, BST204, purified ginseng dry extract, contains multiple ginsenosides that can reduce chemotherapy-related fatigue and toxicity. OBJECTIVES: To investigate the effects of BST204 on the alleviation of chemotherapy-induced cachexia using a multimodal approach. METHODS: In a CT26 mouse syngeneic colon cancer model, cachexia was predominantly induced by chemotherapy with 5-fluorouracil (5-FU) than by tumor growth. BST204 at a dose of 100 or 200 mg/kg was administered to 5-FU-treated mice. RESULTS: BST204 significantly mitigated the decrease in tumor-excluded body weight (change in 5-FU group and BST204 groups: - 13% vs. - 6% on day 7; - 30% vs. - 20% on day 11), muscle volume (- 19% vs. - 11%), and fat volume (- 91% vs. - 56%). The anti-cachectic effect of BST204 was histologically demonstrated by an improved balance between muscle regeneration and degeneration and a decrease in muscle cross-sectional area reduction. CONCLUSION: Chemotherapy-induced cachexia was biochemically and metabolically characterized by activated inflammation, enhanced oxidative stress, increased protein degradation, decreased protein stabilization, reduced glucose-mediated energy production, and deactivated glucose-mediated biosynthesis. These adverse effects were significantly improved by BST204 treatment. Overall, our multimodal study demonstrated that BST204 could effectively alleviate chemotherapy-induced cachexia.


Assuntos
Caquexia/induzido quimicamente , Caquexia/tratamento farmacológico , Tratamento Farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Extratos Vegetais/farmacologia , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Glucose/metabolismo , Inflamação , Interleucina-6/sangue , Masculino , Metabolômica , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo
14.
Rapid Commun Mass Spectrom ; 35(4): e8995, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33140500

RESUMO

Measuring the stable isotope compositions of atmospheric CO2 is common in earth and atmospheric sciences, and various analytical methods have been developed utilizing continuous-flow (CF) or dual-inlet (DI) isotope ratio mass spectrometry (IRMS). Air is typically collected via passive, manual, or automated collection methods and the volume of the air sample ranges from 10 to 300 mL for CF-IRMS to >1 L for DI-IRMS to yield a measurable amount of atmospheric CO2 gas. It has been determined that the integrity of vials and flasks for air sample storage can be compromised after 3 days of air collection for δ13 C values and within 10 hours for δ18 O values. Air samples must be purified after collection to remove constituents of air, such as Ar, O2 , N2 , N2 O, and water vapor, to avoid isobaric interferences during mass spectrometric measurement. Purification is generally undertaken by utilizing commercial or custom-made preconcentration devices, the blanking method for CF-IRMS, or an offline/online cryogenic separation using a vacuum line for DI-IRMS. Ambient N2 O is a component of air that may affect analytical results and thus must either be corrected for or be removed using a gas chromatographic column. In some cases, water is removed during air collection by using a common chemical desiccant, magnesium perchlorate (Mg(ClO4 )2 ), or by a dry ice/alcohol mixture (-78°C). Lastly, a linearity issue for IRMS due to the low amount of purified CO2 from a typical ambient air sample must be considered. In general, analytical precisions of 0.02-0.21‰ and 0.04-0.34‰ for CF-IRMS and 0.01-0.02‰ and 0.01-0.02‰ for DI-IRMS are expected for δ13 C and δ18 O measurements, respectively.

15.
PLoS Genet ; 14(9): e1007628, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30235212

RESUMO

Plants defend themselves against pathogens by activating an array of immune responses. Unfortunately, immunity programs may also cause unintended collateral damage to the plant itself. The quantitative disease resistance gene ACCELERATED CELL DEATH 6 (ACD6) serves to balance growth and pathogen resistance in natural populations of Arabidopsis thaliana. An autoimmune allele, ACD6-Est, which strongly reduces growth under specific laboratory conditions, is found in over 10% of wild strains. There is, however, extensive variation in the strength of the autoimmune phenotype expressed by strains with an ACD6-Est allele, indicative of genetic modifiers. Quantitative genetic analysis suggests that ACD6 activity can be modulated in diverse ways, with different strains often carrying different large-effect modifiers. One modifier is SUPPRESSOR OF NPR1-1, CONSTITUTIVE 1 (SNC1), located in a highly polymorphic cluster of nucleotide-binding domain and leucine-rich repeat (NLR) immune receptor genes, which are prototypes for qualitative disease resistance genes. Allelic variation at SNC1 correlates with ACD6-Est activity in multiple accessions, and a common structural variant affecting the NL linker sequence can explain differences in SNC1 activity. Taken together, we find that an NLR gene can mask the activity of an ACD6 autoimmune allele in natural A. thaliana populations, thereby linking different arms of the plant immune system.


Assuntos
Anquirinas/imunologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/imunologia , Arabidopsis/imunologia , Autoimunidade/genética , Regulação da Expressão Gênica de Plantas/imunologia , Doenças das Plantas/imunologia , Imunidade Vegetal/genética , Alelos , Anquirinas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Resistência à Doença/genética , Mutação , Doenças das Plantas/genética , Plantas Geneticamente Modificadas , Transdução de Sinais/imunologia
16.
Int J Mol Sci ; 22(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34768819

RESUMO

Clustered regularly interspaced palindromic repeat (CRISPR)-mediated mutagenesis has become an important tool in plant research, enabling the characterization of genes via gene knock-out. CRISPR genome editing tools can be applied to generate multi-gene knockout lines. Typically, multiple single-stranded, single guide RNAs (gRNAs) must be expressed in an organism to target multiple genes simultaneously; however, a single gRNA can target multiple genes if the target genes share similar sequences. A gene cluster comprising ACQUIRED OSMOTOLERANCE (ACQOS; AT5G46520) and neighboring nucleotide-binding leucine-rich repeats (NLRs; AT5G46510) is associated with osmotic tolerance. To investigate the role of ACQOS and the tandemly arranged NLR in osmotic tolerance, we introduced small insertion/deletion mutations into two target genes using a single gRNA and obtained transformant plant lines with three different combinations of mutant alleles. We then tested our mutant lines for osmotic tolerance after a salt-stress acclimation period by determining the chlorophyll contents of the mutant seedlings. Our results strongly suggest that ACQOS is directly associated with salt resistance, while the neighboring NLR is not. Here, we confirmed previous findings suggesting the involvement of ACQOS in salt tolerance and demonstrated the usefulness of CRISPR-mediated mutagenesis in validating the functions of genes in a single genetic background.


Assuntos
Arabidopsis/genética , Família Multigênica , Tolerância ao Sal/genética , Arabidopsis/fisiologia , Sistemas CRISPR-Cas , Clorofila/metabolismo , Edição de Genes , Plantas Geneticamente Modificadas
17.
Anal Chem ; 92(7): 4980-4989, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32167278

RESUMO

Quantitative proteomic platforms based on precursor intensity in mass spectrometry (MS1-level) uniquely support in vivo metabolic labeling with superior quantification accuracy but suffer from limited multiplexity (≤3-plex) and frequent missing quantities. Here we present a new MS1-level quantification platform that allows maximal multiplexing with high quantification accuracy and precision for the given labeling scheme. The platform currently comprises 6-plex in vivo SILAC or in vitro diethylation labeling with a dedicated algorithm and is also expandable to higher multiplexity (e.g., nine-plex for SILAC). For complex samples with broad dynamic ranges such as total cell lysates, our platform performs highly accurately and free of missing quantities. Furthermore, we successfully applied our method to measure protein synthesis rate under heat shock response in human cells by 6-plex pulsed SILAC experiments, demonstrating the unique biological merits of our in vivo platform to disclose translational regulations for cellular response to stress.


Assuntos
Proteínas de Neoplasias/análise , Proteoma/análise , Células HeLa , Humanos , Espectrometria de Massas , Células Tumorais Cultivadas
18.
Nat Methods ; 14(9): 909-914, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28783154

RESUMO

Top-down proteomics, the analysis of intact proteins in their endogenous form, preserves valuable information about post-translation modifications, isoforms and proteolytic processing. The quality of top-down liquid chromatography-tandem MS (LC-MS/MS) data sets is rapidly increasing on account of advances in instrumentation and sample-processing protocols. However, top-down mass spectra are substantially more complex than conventional bottom-up data. New algorithms and software tools for confident proteoform identification and quantification are needed. Here we present Informed-Proteomics, an open-source software suite for top-down proteomics analysis that consists of an LC-MS feature-finding algorithm, a database search algorithm, and an interactive results viewer. We compare our tool with several other popular tools using human-in-mouse xenograft luminal and basal breast tumor samples that are known to have significant differences in protein abundance based on bottom-up analysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Proteoma/análise , Proteoma/química , Software , Espectrometria de Massas em Tandem/métodos , Interface Usuário-Computador , Algoritmos , Linguagens de Programação , Proteômica/métodos , Integração de Sistemas
19.
Nature ; 508(7496): 364-8, 2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-24740066

RESUMO

The geochemistry of Martian meteorites provides a wealth of information about the solid planet and the surface and atmospheric processes that occurred on Mars. The degree to which Martian magmas may have assimilated crustal material, thus altering the geochemical signatures acquired from their mantle sources, is unclear. This issue features prominently in efforts to understand whether the source of light rare-earth elements in enriched shergottites lies in crustal material incorporated into melts or in mixing between enriched and depleted mantle reservoirs. Sulphur isotope systematics offer insight into some aspects of crustal assimilation. The presence of igneous sulphides in Martian meteorites with sulphur isotope signatures indicative of mass-independent fractionation suggests the assimilation of sulphur both during passage of magmas through the crust of Mars and at sites of emplacement. Here we report isotopic analyses of 40 Martian meteorites that represent more than half of the distinct known Martian meteorites, including 30 shergottites (28 plus 2 pairs, where pairs are separate fragments of a single meteorite), 8 nakhlites (5 plus 3 pairs), Allan Hills 84001 and Chassigny. Our data provide strong evidence that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet's history. The signature of mass-independent fractionation observed also indicates that the atmospheric imprint of photochemical processing preserved in Martian meteoritic sulphide and sulphate is distinct from that observed in terrestrial analogues, suggesting fundamental differences between the dominant sulphur chemistry in the atmosphere of Mars and that in the atmosphere of Earth.

20.
Nature ; 513(7518): 382-7, 2014 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-25043054

RESUMO

Extensive genomic characterization of human cancers presents the problem of inference from genomic abnormalities to cancer phenotypes. To address this problem, we analysed proteomes of colon and rectal tumours characterized previously by The Cancer Genome Atlas (TCGA) and perform integrated proteogenomic analyses. Somatic variants displayed reduced protein abundance compared to germline variants. Messenger RNA transcript abundance did not reliably predict protein abundance differences between tumours. Proteomics identified five proteomic subtypes in the TCGA cohort, two of which overlapped with the TCGA 'microsatellite instability/CpG island methylation phenotype' transcriptomic subtype, but had distinct mutation, methylation and protein expression patterns associated with different clinical outcomes. Although copy number alterations showed strong cis- and trans-effects on mRNA abundance, relatively few of these extend to the protein level. Thus, proteomics data enabled prioritization of candidate driver genes. The chromosome 20q amplicon was associated with the largest global changes at both mRNA and protein levels; proteomics data highlighted potential 20q candidates, including HNF4A (hepatocyte nuclear factor 4, alpha), TOMM34 (translocase of outer mitochondrial membrane 34) and SRC (SRC proto-oncogene, non-receptor tyrosine kinase). Integrated proteogenomic analysis provides functional context to interpret genomic abnormalities and affords a new paradigm for understanding cancer biology.


Assuntos
Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Genômica , Proteoma/metabolismo , Neoplasias Retais/genética , Neoplasias Retais/metabolismo , Transcriptoma/genética , Cromossomos Humanos Par 20/genética , Ilhas de CpG/genética , Variações do Número de Cópias de DNA/genética , Metilação de DNA , Fator 4 Nuclear de Hepatócito/genética , Humanos , Repetições de Microssatélites/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Mutação de Sentido Incorreto/genética , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Mutação Puntual/genética , Proteoma/análise , Proteoma/genética , Proteômica , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas pp60(c-src)/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/análise , RNA Neoplásico/genética , RNA Neoplásico/metabolismo
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