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1.
Immunity ; 56(9): 2121-2136.e6, 2023 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-37659412

RESUMEN

Genetic association studies have demonstrated the critical involvement of the microglial immune response in Alzheimer's disease (AD) pathogenesis. Phospholipase C-gamma-2 (PLCG2) is selectively expressed by microglia and functions in many immune receptor signaling pathways. In AD, PLCG2 is induced uniquely in plaque-associated microglia. A genetic variant of PLCG2, PLCG2P522R, is a mild hypermorph that attenuates AD risk. Here, we identified a loss-of-function PLCG2 variant, PLCG2M28L, that confers an increased AD risk. PLCG2P522R attenuated disease in an amyloidogenic murine AD model, whereas PLCG2M28L exacerbated the plaque burden associated with altered phagocytosis and Aß clearance. The variants bidirectionally modulated disease pathology by inducing distinct transcriptional programs that identified microglial subpopulations associated with protective or detrimental phenotypes. These findings identify PLCG2M28L as a potential AD risk variant and demonstrate that PLCG2 variants can differentially orchestrate microglial responses in AD pathogenesis that can be therapeutically targeted.


Asunto(s)
Enfermedad de Alzheimer , Animales , Ratones , Enfermedad de Alzheimer/genética , Estudios de Asociación Genética , Microglía , Fagocitosis/genética , Fenotipo , Placa Amiloide , Fosfolipasa C gamma/metabolismo
2.
Nature ; 614(7947): 303-308, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36697825

RESUMEN

Flowering plants have evolved numerous intraspecific and interspecific prezygotic reproductive barriers to prevent production of unfavourable offspring1. Within a species, self-incompatibility (SI) is a widely utilized mechanism that rejects self-pollen2,3 to avoid inbreeding depression. Interspecific barriers restrain breeding between species and often follow the SI × self-compatible (SC) rule, that is, interspecific pollen is unilaterally incompatible (UI) on SI pistils but unilaterally compatible (UC) on SC pistils1,4-6. The molecular mechanisms underlying SI, UI, SC and UC and their interconnections in the Brassicaceae remain unclear. Here we demonstrate that the SI pollen determinant S-locus cysteine-rich protein/S-locus protein 11 (SCR/SP11)2,3 or a signal from UI pollen binds to the SI female determinant S-locus receptor kinase (SRK)2,3, recruits FERONIA (FER)7-9 and activates FER-mediated reactive oxygen species production in SI stigmas10,11 to reject incompatible pollen. For compatible responses, diverged pollen coat protein B-class12-14 from SC and UC pollen differentially trigger nitric oxide, nitrosate FER to suppress reactive oxygen species in SC stigmas to facilitate pollen growth in an intraspecies-preferential manner, maintaining species integrity. Our results show that SRK and FER integrate mechanisms underlying intraspecific and interspecific barriers and offer paths to achieve distant breeding in Brassicaceae crops.


Asunto(s)
Brassicaceae , Flores , Hibridación Genética , Proteínas de Plantas , Polinización , Brassicaceae/genética , Brassicaceae/metabolismo , Depresión Endogámica , Óxido Nítrico/metabolismo , Fosfotransferasas/metabolismo , Fitomejoramiento , Proteínas de Plantas/metabolismo , Polen/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Especificidad de la Especie , Flores/metabolismo , Autofecundación
3.
Nature ; 580(7805): 653-657, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32350464

RESUMEN

The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1; hereafter, mfec)1, simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1S205F mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.


Asunto(s)
Arabidopsis/genética , Arabidopsis/microbiología , Redes Reguladoras de Genes/genética , Componentes Aéreos de las Plantas/genética , Componentes Aéreos de las Plantas/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/prevención & control , Arabidopsis/inmunología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Muerte Celular , Ambiente , Firmicutes/genética , Firmicutes/aislamiento & purificación , Genes de Plantas/genética , Genotipo , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Homeostasis , Microbiota/genética , Microbiota/fisiología , Mutación , Fenotipo , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/microbiología , Proteobacteria/genética , Proteobacteria/aislamiento & purificación
4.
Proc Natl Acad Sci U S A ; 120(17): e2218617120, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37068254

RESUMEN

We have developed workflows to align 3D magnetic resonance histology (MRH) of the mouse brain with light sheet microscopy (LSM) and 3D delineations of the same specimen. We start with MRH of the brain in the skull with gradient echo and diffusion tensor imaging (DTI) at 15 µm isotropic resolution which is ~ 1,000 times higher than that of most preclinical MRI. Connectomes are generated with superresolution tract density images of ~5 µm. Brains are cleared, stained for selected proteins, and imaged by LSM at 1.8 µm/pixel. LSM data are registered into the reference MRH space with labels derived from the ABA common coordinate framework. The result is a high-dimensional integrated volume with registration (HiDiver) with alignment precision better than 50 µm. Throughput is sufficiently high that HiDiver is being used in quantitative studies of the impact of gene variants and aging on mouse brain cytoarchitecture and connectomics.


Asunto(s)
Imagen de Difusión Tensora , Microscopía , Ratones , Animales , Imagen de Difusión Tensora/métodos , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Espectroscopía de Resonancia Magnética , Imagen de Difusión por Resonancia Magnética/métodos
5.
Nat Methods ; 19(7): 854-864, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35761067

RESUMEN

Lactylation was initially discovered on human histones. Given its nascence, its occurrence on nonhistone proteins and downstream functional consequences remain elusive. Here we report a cyclic immonium ion of lactyllysine formed during tandem mass spectrometry that enables confident protein lactylation assignment. We validated the sensitivity and specificity of this ion for lactylation through affinity-enriched lactylproteome analysis and large-scale informatic assessment of nonlactylated spectral libraries. With this diagnostic ion-based strategy, we confidently determined new lactylation, unveiling a wide landscape beyond histones from not only the enriched lactylproteome but also existing unenriched human proteome resources. Specifically, by mining the public human Meltome Atlas, we found that lactylation is common on glycolytic enzymes and conserved on ALDOA. We also discovered prevalent lactylation on DHRS7 in the draft of the human tissue proteome. We partially demonstrated the functional importance of lactylation: site-specific engineering of lactylation into ALDOA caused enzyme inhibition, suggesting a lactylation-dependent feedback loop in glycolysis.


Asunto(s)
Histonas , Proteoma , Glucólisis , Histonas/metabolismo , Humanos , Oxidorreductasas/metabolismo , Proteoma/metabolismo , Espectrometría de Masas en Tándem/métodos
6.
PLoS Pathog ; 19(12): e1011876, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38100539

RESUMEN

Xanthomonas citri pv. citri (Xcc) causes the devastating citrus canker disease. Xcc is known to have been introduced into Florida, USA in at least three different events in 1915, 1986 and 1995 with the first two claimed to be eradicated. It was questioned whether the Xcc introduction in 1986 has been successfully eradicated. Furthermore, it is unknown how Xcc has spread throughout the citrus groves in Florida. In this study, we investigated the population structure of Xcc to address these questions. We sequenced the whole genome of 343 Xcc strains collected from Florida groves between 1997 and 2016. Our analysis revealed two distinct clusters of Xcc. Our data strongly indicate that the claimed eradication of the 1986 Xcc introduction was not successful and Xcc strains from 1986 introduction were present in samples from at least 8 counties collected after 1994. Importantly, our data revealed that the Cluster 2 strains, which are present in all 20 citrus-producing counties sampled in Florida, originated from the Xcc introduction event in the Miami area in 1995. Our data suggest that Polk County is the epicenter of the dispersal of Cluster 2 Xcc strains, which is consistent with the fact that three major hurricanes passed through Polk County in 2004. As copper-based products have been extensively used to control citrus canker, we also investigated whether Xcc strains have developed resistance to copper. Notably, none of the 343 strains contained known copper resistance genes. Twenty randomly selected Xcc strains displayed sensitivity to copper. Overall, this study provides valuable insights into the introduction, eradication, spread, and copper resistance of Xcc in Florida.


Asunto(s)
Citrus , Xanthomonas , Cobre , Filogenia , Xanthomonas/genética , Enfermedades de las Plantas/genética
7.
Plant J ; 113(1): 145-159, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36453190

RESUMEN

Structural variations (SVs) are critical factors affecting genome evolution and important traits. However, identification results and functional analyses of SVs in upland cotton are rare. Here, based on the genetic relationships, breeding history and cumulative planting area of upland cotton in China, nine predominant cultivars from the past 60 years (1950s-2010s) were selected for long read sequencing to uncover genic variations and breeding improvement targets for this crop. Based on the ZM24 reference genome, 0.88-1.47 × 104 SVs per cultivar were identified, and an SV set was constructed. SVs affected the expression of a large number of genes during fiber elongation, and a transposable element insertion resulted in the glandless phenotype in upland cotton. Six widespread inversions were identified based on nine draft genomes and high-throughput chromosome conformation capture data. Multiple haplotype blocks that were always associated with aggregated SVs were demonstrated to play a pivotal role in the agronomic traits of upland cotton and drove its adaptation to the northern planting region. Exotic introgression was the source of these haplotype blocks and increased the genetic diversity of upland cotton. Our results enrich the genome resources of upland cotton, and the identified SVs will promote genetic and breeding research in cotton.


Asunto(s)
Fitomejoramiento , Sitios de Carácter Cuantitativo , Fenotipo , Haplotipos , Alelos , Gossypium/genética , Fibra de Algodón
8.
Plant J ; 114(3): 519-533, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36786729

RESUMEN

Flowering cherry is a very popular species around the world. High-quality genome resources for different elite cultivars are needed, and the understanding of their origins and the regulation of key ornamental traits are limited for this tree. Here, a high-quality chromosome-scale genome of Prunus campanulata 'Plena' (PCP), which is a native and elite flowering cherry cultivar in China, was generated. The contig N50 of the genome was 18.31 Mb, and 99.98% of its contigs were anchored to eight chromosomes. Furthermore, a total of 306 accessions of flowering cherry germplasm and six lines of outgroups were collected. Resequencing of these 312 lines was performed, and 761 267 high-quality genomic variants were obtained. The origins of flowering cherry were predicted, and these 306 accessions could be classified into three clades, A, B and C. According to phylogenetic analysis, we predicted two origins of flowering cherry. Flowering cherry in clade A originated in southern China, such as in the Himalayan Mountains, while clades B and C originated in northeastern China. Finally, a genome-wide association study of flower colour was performed for all 312 accessions of flowering cherry germplasm. A total of seven quantitative trait loci (QTLs) were identified. One gene encoding glycosylate transferase was predicted as the candidate gene for one QTL. Taken together, our results provide a valuable genomic resource and novel insights into the origin, evolution and flower colour variations of flowering cherry.


Asunto(s)
Estudio de Asociación del Genoma Completo , Prunus avium , Filogenia , Color , Prunus avium/genética , Flores/genética
9.
BMC Genomics ; 25(1): 521, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802746

RESUMEN

BACKGROUND: Citrus is a major fruit crop, and RNA-sequencing (RNA-seq) data can be utilized to investigate its gene functions, heredity, evolution, development, and the detection of genes linked to essential traits or resistance to pathogens. However, it is challenging to use the public RNA-seq datasets for researchers without bioinformatics training, and expertise. RESULTS: OrangeExpDB is a web-based database that integrates transcriptome data of various Citrus spp., including C. limon (L.) Burm., C. maxima (Burm.) Merr., C. reticulata Blanco, C. sinensis (L.) Osbeck, and Poncirus trifoliata (L.) Raf., downloaded from the NCBI SRA database. It features a blast tool for browsing and searching, enabling quick download of expression matrices for different transcriptome samples. Expression of genes of interest can be easily generated by searching gene IDs or sequence similarity. Expression data in text format can be downloaded and presented as a heatmap, with additional sample information provided at the bottom of the webpage. CONCLUSIONS: Researchers can utilize OrangeExpDB to facilitate functional genomic analysis and identify key candidate genes, leveraging publicly available citrus RNA-seq datasets. OrangeExpDB can be accessed at http://www.orangeexpdb.com/ .


Asunto(s)
Citrus , Bases de Datos Genéticas , Citrus/genética , Transcriptoma , Perfilación de la Expresión Génica/métodos , Biología Computacional/métodos , Regulación de la Expresión Génica de las Plantas
10.
Clin Immunol ; 261: 109938, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38346464

RESUMEN

Z-DNA binding protein 1 (ZBP1), a cytosolic nucleic acid sensor for Z-form nucleic acids (Z-NA), can detect both exogenous and endogenous nucleic acids. Upon sensing of self Z-NA or exposure to diverse noxious stimuli, ZBP1 regulates inflammation by activating nuclear factor kappa B and interferon regulating factor 3 signaling pathways. In addition, ZBP1 promotes the assembly of ZBP1 PANoptosome, which initiates caspase 3-mediated apoptosis, mixed lineage kinase domain like pseudokinase (MLKL)-mediated necroptosis, and gasdermin D (GSDMD)-mediated pyroptosis (PANoptosis), leading to the release of various damage-associated molecular patterns. Thereby, ZBP1 is implicated in the development and progression of diverse sterile inflammatory diseases. This review outlines the expression, structure, and function of ZBP1, along with its dual roles in controlling inflammation and cell death to orchestrate innate immunity in sterile inflammation, especially autoimmune diseases, and cancers. ZBP1 has emerged as an attractive therapeutic target for various sterile inflammatory diseases.


Asunto(s)
Ácidos Nucleicos , Humanos , Apoptosis , Muerte Celular , Piroptosis , Inflamación/genética
11.
New Phytol ; 241(2): 732-746, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37872751

RESUMEN

Callus formation is important for numerous biological processes in plants. Previously, we revealed that the PdeWRKY75-PdeRBOHB module positively regulates hydrogen peroxide (H2 O2 ) accumulation, thereby affecting callus formation in poplar. In this study, we identified and confirmed a transcription factor, PdeERF114, that interacts with PdeWRKY75 both in vitro and in vivo. Gene expression analysis identified both PdeRBOHB and PdeEXPB2 as downstream genes of PdeERF114 and PdeWRKY75. Overexpression (OE) and reduced-expression (RE) transgenic poplar lines for these four genes were generated, and the observation of callus formation was also performed in all plant materials. We demonstrated that PdeERF114 and PdeWRKY75 formed a protein complex and that this complex could bind W-Box motifs in the promoters of PdeRBOHB and PdeEXPB2, thereby positively regulating the expression of PdeRBOHB and PdeEXPB2. The OE/RE transgenic lines for these four genes also showed enhanced/reduced callus formation. Overall, we revealed a novel gene regulatory network for the regulation of callus formation in plants that involves four genes and regulates callus formation through two pathways: the accumulation of H2 O2 in explants and the relaxation of cell walls. In the future, the four genes could be used to enhance transformation effectiveness in genetic engineering.


Asunto(s)
Populus , Factores de Transcripción , Regiones Promotoras Genéticas/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Perfilación de la Expresión Génica , Pared Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Populus/genética , Populus/metabolismo , Plantas Modificadas Genéticamente/metabolismo
12.
J Magn Reson Imaging ; 59(2): 376-396, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37477576

RESUMEN

Diffusion-weighted imaging (DWI) is an established MRI technique that can investigate tissue microstructure at the scale of a few micrometers. Musculoskeletal tissues typically have a highly ordered structure to fulfill their functions and therefore represent an optimal application of DWI. Even more since disruption of tissue organization affects its biomechanical properties and may indicate irreversible damage. The application of DWI to the musculoskeletal system faces application-specific challenges on data acquisition including susceptibility effects, the low T2 relaxation time of most musculoskeletal tissues (2-70 msec) and the need for sub-millimetric resolution. Thus, musculoskeletal applications have been an area of development of new DWI methods. In this review, we provide an overview of the technical aspects of DWI acquisition including diffusion-weighting, MRI pulse sequences and different diffusion regimes to study tissue microstructure. For each tissue type (growth plate, articular cartilage, muscle, bone marrow, intervertebral discs, ligaments, tendons, menisci, and synovium), the rationale for the use of DWI and clinical studies in support of its use as a biomarker are presented. The review describes studies showing that DTI of the growth plate has predictive value for child growth and that DTI of articular cartilage has potential to predict the radiographic progression of joint damage in early stages of osteoarthritis. DTI has been used extensively in skeletal muscle where it has shown potential to detect microstructural and functional changes in a wide range of muscle pathologies. DWI of bone marrow showed to be a valuable tool for the diagnosis of benign and malignant acute vertebral fractures and bone metastases. DTI and diffusion kurtosis have been investigated as markers of early intervertebral disc degeneration and lower back pain. Finally, promising new applications of DTI to anterior cruciate ligament grafts and synovium are presented. The review ends with an overview of the use of DWI in clinical routine. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.


Asunto(s)
Enfermedades de la Médula Ósea , Sistema Musculoesquelético , Fracturas de la Columna Vertebral , Niño , Humanos , Imagen de Difusión por Resonancia Magnética/métodos , Sistema Musculoesquelético/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Fracturas de la Columna Vertebral/patología
14.
Phytopathology ; 114(5): 961-970, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38478730

RESUMEN

Citrus Huanglongbing (HLB) caused by 'Candidatus Liberibacter asiaticus' (CLas) is the most devastating citrus disease worldwide. CLas induces systemic and chronic reactive oxygen species (ROS) production, which has been suggested to be a primary cause of cell death in phloem tissues and subsequent HLB symptoms. Mitigating oxidative stress caused by CLas using horticultural approaches has been suggested as a useful strategy to reduce HLB damages. To provide information regarding the application timing to mitigate ROS, we investigated monthly dynamics of CLas concentration, CLas-triggered ROS, and phloem cell death in the bark tissues of asymptomatic and symptomatic branches of HLB-positive Hamlin and Valencia sweet orange trees in the field. Healthy branches in the screenhouse were used as controls. CLas concentration exhibited significant variations over the course of the year, with two distinct peaks observed in Florida citrus groves-late spring/early summer and late fall. Within both Hamlin and Valencia asymptomatic tissues, CLas concentration demonstrated a negative correlation with the deviation between the monthly average mean temperature and the optimal temperature for CLas colonization in plants (25.7°C). However, such a correlation was not evident in symptomatic tissues of Hamlin or Valencia sweet oranges. ROS levels were consistently higher in symptomatic or asymptomatic branches than in healthy branches in most months. ROS concentrations were higher in symptomatic branches than in asymptomatic branches in most months. CLas triggered significant increases in ion leakage in most months for asymptomatic and symptomatic branches compared with healthy controls. In asymptomatic branches of Hamlin, a positive correlation was observed between CLas concentration and ROS concentrations, CLas concentration and ion leakage levels, as well as ROS and ion leakage. Intriguingly, such a relationship was not observed in Valencia asymptomatic branches or in the symptomatic branches of Hamlin and Valencia. This study sheds light on the pathogenicity of CLas by providing useful information on the temporal dynamics of ROS production, phloem cell death, and CLas growth, as well as provides useful information in determining the timing for application of antioxidants and antimicrobial agents to control HLB.


Asunto(s)
Citrus sinensis , Enfermedades de las Plantas , Especies Reactivas de Oxígeno , Rhizobiaceae , Especies Reactivas de Oxígeno/metabolismo , Citrus sinensis/microbiología , Enfermedades de las Plantas/microbiología , Rhizobiaceae/fisiología , Floema/microbiología , Corteza de la Planta/microbiología , Liberibacter , Iones/metabolismo
15.
Phytopathology ; : PHYTO03240084RVW, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38648116

RESUMEN

In this review, we highlight studies in which whole-genome sequencing, comparative genomics, and population genomics have provided unprecedented insights into past and ongoing pathogen evolution. These include new understandings of the adaptive evolution of secretion systems and their effectors. We focus on Xanthomonas pathosystems that have seen intensive study and improved our understanding of pathogen emergence and evolution, particularly in the context of host specialization: citrus canker, bacterial blight of rice, and bacterial spot of tomato and pepper. Across pathosystems, pathogens appear to follow a pattern of bursts of evolution and diversification that impact host adaptation. There remains a need for studies on the mechanisms of host range evolution and genetic exchange among closely related but differentially host-specialized species and to start moving beyond the study of specific strain and host cultivar pairwise interactions to thinking about these pathosystems in a community context.

16.
Phytopathology ; 114(5): 837-842, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38815216

RESUMEN

Plant diseases significantly impact food security and food safety. It was estimated that food production needs to increase by 50% to feed the projected 9.3 billion people by 2050. Yet, plant pathogens and pests are documented to cause up to 40% yield losses in major crops, including maize, rice, and wheat, resulting in annual worldwide economic losses of approximately US$220 billion. Yield losses due to plant diseases and pests are estimated to be 21.5% (10.1 to 28.1%) in wheat, 30.3% (24.6 to 40.9%) in rice, and 22.6% (19.5 to 41.4%) in maize. In March 2023, The American Phytopathological Society (APS) conducted a survey to identify and rank key challenges in plant pathology in the next decade. Phytopathology subsequently invited papers that address those key challenges in plant pathology, and these were published as a special issue. The key challenges identified include climate change effect on the disease triangle and outbreaks, plant disease resistance mechanisms and its applications, and specific diseases including those caused by Candidatus Liberibacter spp. and Xylella fastidiosa. Additionally, disease detection, natural and man-made disasters, and plant disease control strategies were explored in issue articles. Finally, aspects of open access and how to publish articles to maximize the Findability, Accessibility, Interoperability, and Reuse of digital assets in plant pathology were described. Only by identifying the challenges and tracking progress in developing solutions for them will we be able to resolve the issues in plant pathology and ultimately ensure plant health, food security, and food safety.


Asunto(s)
Productos Agrícolas , Enfermedades de las Plantas , Patología de Plantas , Enfermedades de las Plantas/microbiología , Productos Agrícolas/microbiología , Resistencia a la Enfermedad , Cambio Climático , Xylella
17.
PLoS Genet ; 17(1): e1009310, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33465093

RESUMEN

Transcription activator-like effectors (TALEs) are virulence factors of Xanthomonas that induce the expression of host susceptibility (S) genes by specifically binding to effector binding elements (EBEs) in their promoter regions. The DNA binding specificity of TALEs is dictated by their tandem repeat regions, which are highly variable between different TALEs. Mutation of the EBEs of S genes is being utilized as a key strategy to generate resistant crops against TALE-dependent pathogens. However, TALE adaptations through rearrangement of their repeat regions is a potential obstacle for successful implementation of this strategy. We investigated the consequences of TALE adaptations in the citrus pathogen Xanthomonas citri subsp. citri (Xcc), in which PthA4 is the TALE required for pathogenicity, whereas CsLOB1 is the corresponding susceptibility gene, on host resistance. Seven TALEs, containing two-to-nine mismatching-repeats to the EBEPthA4 that were unable to induce CsLOB1 expression, were introduced into Xcc pthA4:Tn5 and adaptation was simulated by repeated inoculations into and isolations from sweet orange for a duration of 30 cycles. While initially all strains failed to promote disease, symptoms started to appear between 9-28 passages in four TALEs, which originally harbored two-to-five mismatches. Sequence analysis of adapted TALEs identified deletions and mutations within the TALE repeat regions which enhanced putative affinity to the CsLOB1 promoter. Sequence analyses suggest that TALEs adaptations result from recombinations between repeats of the TALEs. Reintroduction of these adapted TALEs into Xcc pthA4:Tn5 restored the ability to induce the expression of CsLOB1, promote disease symptoms and colonize host plants. TALEs harboring seven-to-nine mismatches were unable to adapt to overcome the incompatible interaction. Our study experimentally documented TALE adaptations to incompatible EBE and provided strategic guidance for generation of disease resistant crops against TALE-dependent pathogens.


Asunto(s)
Interacciones Huésped-Patógeno/genética , Efectores Tipo Activadores de la Transcripción/genética , Factores de Virulencia/genética , Xanthomonas/genética , Proteínas Bacterianas/genética , Citrus/genética , Citrus/microbiología , Regulación de la Expresión Génica de las Plantas/genética , Mutación/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Regiones Promotoras Genéticas/genética , Xanthomonas/patogenicidad
18.
Alzheimers Dement ; 20(6): 4126-4146, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38735056

RESUMEN

INTRODUCTION: MODEL-AD (Model Organism Development and Evaluation for Late-Onset Alzheimer's Disease) is creating and distributing novel mouse models with humanized, clinically relevant genetic risk factors to capture the trajectory and progression of late-onset Alzheimer's disease (LOAD) more accurately. METHODS: We created the LOAD2 model by combining apolipoprotein E4 (APOE4), Trem2*R47H, and humanized amyloid-beta (Aß). Mice were subjected to a control diet or a high-fat/high-sugar diet (LOAD2+HFD). We assessed disease-relevant outcome measures in plasma and brain including neuroinflammation, Aß, neurodegeneration, neuroimaging, and multi-omics. RESULTS: By 18 months, LOAD2+HFD mice exhibited sex-specific neuron loss, elevated insoluble brain Aß42, increased plasma neurofilament light chain (NfL), and altered gene/protein expression related to lipid metabolism and synaptic function. Imaging showed reductions in brain volume and neurovascular uncoupling. Deficits in acquiring touchscreen-based cognitive tasks were observed. DISCUSSION: The comprehensive characterization of LOAD2+HFD mice reveals that this model is important for preclinical studies seeking to understand disease trajectory and progression of LOAD prior to or independent of amyloid plaques and tau tangles. HIGHLIGHTS: By 18 months, unlike control mice (e.g., LOAD2 mice fed a control diet, CD), LOAD2+HFD mice presented subtle but significant loss of neurons in the cortex, elevated levels of insoluble Ab42 in the brain, and increased plasma neurofilament light chain (NfL). Transcriptomics and proteomics showed changes in gene/proteins relating to a variety of disease-relevant processes including lipid metabolism and synaptic function. In vivo imaging revealed an age-dependent reduction in brain region volume (MRI) and neurovascular uncoupling (PET/CT). LOAD2+HFD mice also demonstrated deficits in acquisition of touchscreen-based cognitive tasks.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Modelos Animales de Enfermedad , Proteínas tau , Animales , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Ratones , Péptidos beta-Amiloides/metabolismo , Proteínas tau/metabolismo , Proteínas tau/genética , Ratones Transgénicos , Encéfalo/patología , Encéfalo/metabolismo , Sinapsis/patología , Sinapsis/metabolismo , Masculino , Femenino , Humanos
19.
Plant J ; 111(6): 1753-1767, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35883193

RESUMEN

Phosphorus (P) is an important nutrient for plants. Here, we identify a WRKY transcription factor (TF) in poplar (Populus deltoides × Populus euramericana) (PdeWRKY65) that modulates tissue phosphate (Pi) concentrations in poplar. PdeWRKY65 overexpression (OE) transgenic lines showed reduced shoot Pi concentrations under both low and normal Pi availabilities, while PdeWRKY65 reduced expression (RE) lines showed the opposite phenotype. A gene encoding a Pi transporter (PHT), PdePHT1;9, was identified as the direct downstream target of PdeWRKY65 by RNA sequencing (RNA-Seq). The negative regulation of PdePHT1;9 expression by PdeWRKY65 was confirmed by DNA-protein interaction assays, including yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), co-expression of the promoters of PdePHT1;9 and PdeWRKY65 in tobacco (Nicotiana benthamiana) leaves, and chromatin immunoprecipitation-quantitative PCR. A second WRKY TF, PdeWRKY6, was subsequently identified and confirmed to positively regulate the expression of PdePHT1;9 by DNA-protein interaction assays. PdePHT1;9 and PdeWRKY6 OE and RE poplar transgenic lines were used to confirm their positive regulation of shoot Pi concentrations, under both normal and low Pi availabilities. No interaction between PdeWRKY6 and PdeWRKY65 was observed at the DNA or protein levels. Collectively, these data suggest that the low Pi-responsive TFs PdeWRKY6 and PdeWRKY65 independently regulate the expression of PHT1;9 to modulate tissue Pi concentrations in poplar.


Asunto(s)
Populus , Factores de Transcripción , Regulación de la Expresión Génica de las Plantas/genética , Fosfatos/metabolismo , Fósforo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Populus/genética , Populus/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
20.
Mol Genet Genomics ; 298(5): 1073-1085, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37285076

RESUMEN

Age prediction is an important field in forensic and aging research. Traditional methods used DNA methylation, telomere shortening, and mitochondrial DNA mutations to conduct age prediction models. Sex chromosomes, like the Y chromosome, have a significant role in aging as previously reported in hematopoietic disease and many non-reproductive cancers. Until now, there is no age predictor based on the percentage of loss of Y chromosome (LOY). LOY has been previously revealed to be correlated with Alzheimer's disease, short survival, and higher risk of cancer. The possible correlation of LOY between normal aging was not fully explored. In this study, we conducted age prediction by measuring LOY percentage by droplet digital PCR (ddPCR), based on 232 healthy male samples, including 171 blood samples, 49 saliva samples, 12 semen samples. The age group of samples ranges from 0 to 99 years, with two individuals in almost every single age. Pearson correlation method was performed to calculate the correlation index. The result indicated a correlation index of 0.21 (p = 0.0059) between age and LOY percentage in blood samples, with the regression formula being y = - 0.016823 + 0.001098x. The correlation between LOY percentage and age is obvious only when the individuals were divided into different age groups (R = 0.73, p = 0.016). In the studied saliva and semen samples, p-values of the correlation are 0.11 and 0.20, respectively, showing no significant association between age and LOY percentage in these two biological materials. For the first time, we investigated male-specific age predictor based on LOY. The study showed that LOY in leukocytes can be regarded as a male-specific age predictor for age group estimation in forensic genetics. This study might be indicative for forensic applications and aging research.


Asunto(s)
Genética Forense , Neoplasias , Humanos , Masculino , Recién Nacido , Lactante , Preescolar , Niño , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Cromosomas Humanos Y/genética , Leucocitos , Envejecimiento/genética , Neoplasias/genética
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