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Bacteria and archaea possess a striking diversity of CRISPR-Cas systems divided into six types, posing a significant barrier to viral infection. As part of the virus-host arms race, viruses encode protein inhibitors of type I, II, and V CRISPR-Cas systems, but whether there are natural inhibitors of the other, mechanistically distinct CRISPR-Cas types is unknown. Here, we present the discovery of a type III CRISPR-Cas inhibitor, AcrIIIB1, encoded by the Sulfolobus virus SIRV2. AcrIIIB1 exclusively inhibits CRISPR-Cas subtype III-B immunity mediated by the RNase activity of the accessory protein Csx1. AcrIIIB1 does not appear to bind Csx1 but, rather, interacts with two distinct subtype III-B effector complexes-Cmr-α and Cmr-γ-which, in response to protospacer transcript binding, are known to synthesize cyclic oligoadenylates (cOAs) that activate the Csx1 "collateral" RNase. Taken together, we infer that AcrIIIB1 inhibits type III-B CRISPR-Cas immunity by interfering with a Csx1 RNase-related process.
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Proteínas Associadas a CRISPR/fisiologia , Sistemas CRISPR-Cas , Interações Hospedeiro-Patógeno , Rudiviridae/metabolismo , Sulfolobus/virologia , Ribonucleases/metabolismoRESUMO
Intrinsically disordered proteins (IDPs) SAID1/2 are hypothetic dentin sialophosphoprotein-like proteins, but their true functions are unknown. Here, we identified SAID1/2 as negative regulators of SERRATE (SE), a core factor in miRNA biogenesis complex (microprocessor). Loss-of-function double mutants of said1; said2 caused pleiotropic developmental defects and thousands of differentially expressed genes that partially overlapped with those in se. said1; said2 also displayed increased assembly of microprocessor and elevated accumulation of microRNAs (miRNAs). Mechanistically, SAID1/2 promote pre-mRNA processing 4 kinase A-mediated phosphorylation of SE, causing its degradation in vivo. Unexpectedly, SAID1/2 have strong binding affinity to hairpin-structured pri-miRNAs and can sequester them from SE. Moreover, SAID1/2 directly inhibit pri-miRNA processing by microprocessor in vitro. Whereas SAID1/2 did not impact SE subcellular compartmentation, the proteins themselves exhibited liquid-liquid phase condensation that is nucleated on SE. Thus, we propose that SAID1/2 reduce miRNA production through hijacking pri-miRNAs to prevent microprocessor activity while promoting SE phosphorylation and its destabilization in Arabidopsis.
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Proteínas de Arabidopsis , Arabidopsis , Proteínas Intrinsicamente Desordenadas , MicroRNAs , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas Intrinsicamente Desordenadas/genética , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a RNA/metabolismo , Processamento Pós-Transcricional do RNA , MicroRNAs/metabolismo , Ribonuclease III/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Bacteriophages and bacteria are engaged in a constant arms race, continually evolving new molecular tools to survive one another. To protect their genomic DNA from restriction enzymes, the most common bacterial defence systems, double-stranded DNA phages have evolved complex modifications that affect all four bases. This study focuses on modifications at position 7 of guanines. Eight derivatives of 7-deazaguanines were identified, including four previously unknown ones: 2'-deoxy-7-(methylamino)methyl-7-deazaguanine (mdPreQ1), 2'-deoxy-7-(formylamino)methyl-7-deazaguanine (fdPreQ1), 2'-deoxy-7-deazaguanine (dDG) and 2'-deoxy-7-carboxy-7-deazaguanine (dCDG). These modifications are inserted in DNA by a guanine transglycosylase named DpdA. Three subfamilies of DpdA had been previously characterized: bDpdA, DpdA1, and DpdA2. Two additional subfamilies were identified in this work: DpdA3, which allows for complete replacement of the guanines, and DpdA4, which is specific to archaeal viruses. Transglycosylases have now been identified in all phages and viruses carrying 7-deazaguanine modifications, indicating that the insertion of these modifications is a post-replication event. Three enzymes were predicted to be involved in the biosynthesis of these newly identified DNA modifications: 7-carboxy-7-deazaguanine decarboxylase (DpdL), dPreQ1 formyltransferase (DpdN) and dPreQ1 methyltransferase (DpdM), which was experimentally validated and harbors a unique fold not previously observed for nucleic acid methylases.
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Bacteriófagos , Guanina , Bactérias/genética , Bacteriófagos/genética , DNA/genética , Guanina/análogos & derivadosRESUMO
In recent years, live-cell-based drug delivery systems have gained considerable attention. However, shear stress, which accompanies blood flow, may cause cell death and weaken the delivery performance. In this study, we found that reducing cholesterol in macrophage plasma membranes enhanced their tumor targeting ability by more than 2-fold. Our study demonstrates that the reduced cholesterol level deactivated the mammalian target of rapamycin (mTOR) and consequently promoted the nuclear translocation of transcription factor EB (TFEB), which in turn enhanced the expression of superoxide dismutase (SOD) to reduce reactive oxygen species (ROS) induced by shear stress. A proof-of-concept system using low cholesterol macrophages attached to MXene (e.g., l-RX) was fabricated. In a melanoma mouse model, l-RX and laser irradiation treatments eliminated tumors with no recurrences observed in mice. Therefore, cholesterol reduction is a simple and effective way to enhance the targeting performance of macrophage-based drug delivery systems.
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Macrófagos , Superóxido Dismutase , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/metabolismo , Sistemas de Liberação de Medicamentos , Colesterol/metabolismo , Mamíferos/metabolismoRESUMO
The self-powered electrochemical sensor (SPES), an analytical sensing device without external power supply, is integrated with the dual function of power supply and detection performance, which lay the foundation for the development of intelligent and portable electrochemical sensing devices. Herein, a novel SPES based on a zinc-air battery was constructed for the detection of hydrogen sulfide (H2S) in the lysate of colon cancer cells. Typically, an Fe/Fe3C@graphene foam with oxygen reduction performance was used to construct SPES based on a zinc-air battery (ZAB-SPES), which brings the open-circuit voltage to 1.30 V. Among them, the poisoning effect of H2S causes the catalytic performance of the oxygen reduction catalyst to decrease, causing a significant decrease in the discharge voltage of ZAB. Based on this principle, ZAB-SPES was constructed for the detection of H2S using a digital multimeter. The proposed ZAB-SPES demonstrated good selectivity and reproducibility for detecting H2S compared to the results of the H2S-specific fluorescence probe. This strategy enriches the idea of constructing a self-powered sensor and a digital multimeter as detection devices, providing technical support for the portability of SPESs.
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Background: Rheumatoid arthritis (RA) is a systemic and chronic autoimmune disease that is characterized by persistent joint inflammation. RA patients experience a considerably increased risk of cardiovascular-related morbidity and mortality. The current study investigated the association between triglyceride glucose (TyG) index and major adverse cardiovascular events (MACEs) in a predominantly male cohort of RA patients. Methods: A total of 1613 RA patients (81.53% male) were selected from the Kailuan study. The TyG index was calculated as the logarithmic product of fasting blood triglyceride and fasting blood glucose divided by two. MACEs were defined as the composite of non-fatal myocardial infarctions and non-fatal strokes. Cox proportional hazards analysis was performed to study the association between the TyG index and MACEs. Results: A total of 59 MACEs occurred during the median follow-up time of 5.32 years. Following adjustment for age and gender, analysis by multivariable Cox proportional hazards (model 1) showed that an elevated TyG index was associated with an increased risk of MACEs (quartile 2, hazard ratio (HR): 2.741, 95% confidence interval (CI): 1.220-6.157, p = 0.015; quartile 4, HR: 2.521, 95% CI: 1.074-5.917, p = 0.034). After adjustment for other variables, Cox proportional hazards analysis (model 2) showed that an elevated TyG index was independently associated with an increased risk of MACEs (quartile 2, HR: 2.348, 95% CI: 1.009-5.465, p = 0.048). In addition, subgroup analysis showed a higher TyG index was significantly linked to an increased risk of MACEs in patients aged more than 65 years (quartile 2, HR: 6.048, 95% CI: 1.311-27.908, p = 0.021; quartile 4, HR: 12.074, 95% CI: 1.438-101.358, p = 0.022). Conclusions: The TyG index was associated with an increased risk of MACEs in a predominantly male cohort of RA patients. This index may be helpful for the prediction of MACEs in male patients with RA. Clinical Trial Registration: Registration number in the Chinese clinical trial registry: ChiCTR-TNRC-11001489.
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The treatment of infected wounds faces substantial challenges due to the high incidence and serious infection-related complications. Natural-based hydrogel dressings with favorable antibacterial properties and strong applicability are urgently needed. Herein, we developed a composite hydrogel by constructing multiple networks and loading ciprofloxacin for infected wound healing. The hydrogel was synthesized via a Schiff base reaction between carboxymethyl chitosan and oxidized sodium alginate, followed by the polymerization of the acrylamide monomer. The resultant hydrogel dressing possessed a good self-healing ability, considerable compression strength, and reliable compression fatigue resistance. In vitro assessment showed that the composite hydrogel effectively eliminated bacteria and exhibited an excellent biocompatibility. In a model of Staphylococcus aureus-infected full-thickness wounds, wound healing was significantly accelerated without scars through the composite hydrogel by reducing wound inflammation. Overall, this study opens up a new way for developing multifunctional hydrogel wound dressings to treat wound infections.
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Quitosana , Hidrogéis , Hidrogéis/farmacologia , Cicatrização , Antibacterianos/farmacologia , Ciprofloxacina , BandagensRESUMO
The construction of doped molecular clusters is an intriguing way to perform bimetallic doping for electrocatalysts. However, efficiently harnessing the benefits of a doping strategy and alloy engineering to create a nanostructure for electrocatalytic application at the molecular level has consistently posed a challenge. Here we propose an in situ reconstruction strategy aimed at producing an alloy nanostructure through a pyrolysis process, originating from bowknot-like heterometallic clusters. The Schiff base, denoted as ligand L1 (o-vanillin ethylenediamine), was introduced as a precursor to coordinate Fe and Co metals, thereby yielding a heteronuclear metal cluster [(FeCo)(L1)2O]CH3CN. Subsequently, a comprehensive investigation of the in situ reconstruction process [(FeCo)(L1)2O](CH3CN) â [(FeCo)(L1)2O] â [M-O-M/M-O] [CH3+/CH3O+/H2CâN/C2H5+/C4H4+] â [FeCo/Fe3O4/Fe2O3/Co3O4][carbon layer] led to the formation of MOx/CoFe@NC-700 during the pyrolysis. This process reveals that the metals Fe and Co in the clusters undergo partly in situ evolution into FeCo alloys, resulting in the successful preparation of MOx/CoFe@NC (M = Fe, Co) nanomaterials that leverage the advantages of both doping strategies and alloy engineering. The synergistic interaction between alloy particles and metal oxides establishes active sites that contribute to the excellent oxygen evolution (OER) and hydrogen evolution (HER) catalytic behaviors. Notably, these materials exhibit outstanding OER and HER properties under alkaline conditions, with overpotentials of 191 and 88 mV for OER and HER, respectively, at 10 mA cm-2. Investigation of the in situ conversion of Schiff base bimetal clusters into alloy materials through pyrolysis offers a novel strategy for advancing electrocatalytic applications.
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Polycomb group proteins and the related histone modification H3K27me3 can maintain the silencing of key developmental regulators and provide cellular memory. However, how such an epigenetic state is reprogrammed and inherited between generations is poorly understood. Using an ultra-sensitive approach, STAR ChIP-seq, we investigated H3K27me3 across 14 developmental stages along mouse gametogenesis and early development. Interestingly, highly pervasive H3K27me3 is found in regions depleted of transcription and DNA methylation in oocytes. Unexpectedly, we observed extensive loss of promoter H3K27me3 at Hox and other developmental genes upon fertilization. This is accompanied by global erasure of sperm H3K27me3 but inheritance of distal H3K27me3 from oocytes. The resulting allele-specific H3K27me3 patterns persist to blastocysts before being converted to canonical forms in postimplantation embryos, where both H3K4me3/H3K27me3 bivalent promoter marks are restored at developmental genes. Together, these data revealed widespread resetting of epigenetic memory and striking plasticity of epigenome during gametogenesis and early development.
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Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Histonas/genética , Oócitos/metabolismo , Proteínas do Grupo Polycomb/genética , Espermatozoides/metabolismo , Animais , Reprogramação Celular , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Feminino , Fertilização , Gametogênese/genética , Histonas/metabolismo , Padrões de Herança , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oócitos/citologia , Oócitos/crescimento & desenvolvimento , Proteínas do Grupo Polycomb/metabolismo , Regiões Promotoras Genéticas , Espermatozoides/citologia , Espermatozoides/crescimento & desenvolvimento , ZigotoRESUMO
BACKGROUND: To evaluate the safety and effectiveness of a stepwise interventional strategy for the removal of adherent totally implanted central venous access port catheters, consisting of a guidewire support, antegrade coaxial separation, and retrograde coaxial separation with increasing technical complexity. METHODS: This study has a retrospective design. Thirty-two patients who had failed routine removal of the port catheter and were then transferred to interventional radiology between November 2017 and December 2023 were reviewed. The technical success and complication rates were recorded. RESULTS: All adherent catheters were successfully removed without catheter fragmentation, using guidewire support (n = 21), antegrade coaxial separation (n = 5), and retrograde coaxial separation (n = 6). The technical success rate was 100%, and no complications occurred. CONCLUSIONS: The proposed stepwise interventional strategy successfully removed adherent port catheters, with good safety and high effectiveness. It appeared to reduce the incidence of catheter fracture during the removal of adherent totally implantable central venous access port catheters.
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Cateterismo Venoso Central , Cateteres de Demora , Cateteres Venosos Centrais , Remoção de Dispositivo , Humanos , Estudos Retrospectivos , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/instrumentação , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Adulto , Radiografia Intervencionista , Idoso de 80 Anos ou maisRESUMO
Binary metal nickel-iron alloys have been proven to have great potential in oxygen evolution reaction (OER) electrocatalysis, but there are still certain challenges in how to construct more efficient nickel-iron alloy electrocatalysts and maximize their own advantages. In this work, a heterometallic nickel-iron cluster (L = C64 H66 Fe4 N8 Ni2 O19 ) of Schiff base (LH3 = 2-amino-1,3-propanediol salicylaldehyde) is designed as a precursor to explore its behavior in the pyrolysis process under inert atmosphere. The combination of TG-MS, morphology, and X-ray characterization techniques shows that the Schiff base ligands in the heterometallic clusters produces a strong reductive atmosphere during pyrolysis, which enable the two 3d metals Ni and Fe to form NiFe alloys. Moreover, Fe2 O3 /Fe0.64 Ni0.36 @Cs carbon nanomaterials are formed, in which Fe2 O3 /Fe0.64 Ni0.36 is the potential active material for OER. It is also found that the centrosymmetric structure of the heterometallic Schiff base precursor is potentially related to the formation of the Fe2 O3 /Fe0.64 Ni0.36 alloy@carbon structures. The Fe2 O3 /Fe0.64 Ni0.36 @C-800 provides 274 mV overpotential in 1 m KOH solution at 10 mA cm-2 in OER. This work provides an effective basis for further research on Schiff base bimetallic doping-derived carbon nanomaterials as excellent OER electrocatalysts.
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Standardization of immunopeptidomics experiments across laboratories is a pressing issue within the field, and currently a variety of different methods for sample preparation and data analysis tools are applied. Here, we compared different software packages to interrogate immunopeptidomics datasets and found that Peaks reproducibly reports substantially more peptide sequences (~30-70%) compared with Maxquant, Comet, and MS-GF+ at a global false discovery rate (FDR) of <1%. We noted that these differences are driven by search space and spectral ranking. Furthermore, we observed differences in the proportion of peptides binding the human leukocyte antigen (HLA) alleles present in the samples, indicating that sequence-related differences affected the performance of each tested engine. Utilizing data from single HLA allele expressing cell lines, we observed significant differences in amino acid frequency among the peptides reported, with a broadly higher representation of hydrophobic amino acids L, I, P, and V reported by Peaks. We validated these results using data generated with a synthetic library of 2000 HLA-associated peptides from four common HLA alleles with distinct anchor residues. Our investigation highlights that search engines create a bias in peptide sequence depth and peptide amino acid composition, and resulting data should be interpreted with caution.
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Antígenos de Histocompatibilidade Classe I/química , Peptídeos/química , Ferramenta de Busca , Alelos , Sequência de Aminoácidos , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Espectrometria de Massas , Biblioteca de Peptídeos , Peptídeos/genética , Proteômica/métodosRESUMO
BACKGROUND: Fibromyalgia is a chronic pain syndrome characterized by persistent and widespread musculoskeletal pain. Telerehabilitation is a promising treatment for patients with fibromyalgia through long-term monitoring, intervention, supervision, consultation, and education. OBJECTIVE: This study aimed to perform a comprehensive systematic review and meta-analysis of the efficacy and safety of telerehabilitation in patients with fibromyalgia. METHODS: Randomized controlled trials (RCTs) related to fibromyalgia and telerehabilitation were systematically searched in the PubMed, PEDro, Cochrane Library, ScienceDirect, Ovid MEDLINE, Embase, and Web of Science databases from inception to November 13, 2022. Two independent researchers screened the literatures and evaluated the methodological quality using the Cochrane Risk of Bias Tool. The outcome measures included the Fibromyalgia Impact Questionnaire scale, pain intensity, depression, pain catastrophizing, quality of life (QoL), and adverse events. Pooled effect sizes were calculated by Stata SE 15.1; a fixed effects model was used when I2<50%, whereas a random effects model was used when I2≥50%. RESULTS: A total of 14 RCTs with 1242 participants were included in this meta-analysis. The pooled results indicated that the telerehabilitation improved the Fibromyalgia Impact Questionnaire score (weighted mean difference -8.32, 95% CI -11.72 to -4.91; P<.001), pain intensity (standardized mean difference [SMD] -0.62, 95% CI -0.76 to -0.47; P<.001), depression levels (SMD -0.42, 95% CI -0.62 to -0.22; P<.001), pain catastrophizing (weighted mean difference -5.81, 95% CI -9.40 to -2.23; P=.001), and QoL (SMD 0.32, 95% CI 0.18 to 0.47; P<.001) in patients with fibromyalgia compared to control interventions. Only 1 RCT reported a mild adverse event of telerehabilitation; the other 13 RCTs did not mention this. CONCLUSIONS: Telerehabilitation can improve the symptoms and QoL of fibromyalgia. However, the safety of telerehabilitation remains uncertain due to the lack of sufficient evidence for the management of fibromyalgia. More rigorously designed trials are needed in the future to verify the safety and efficacy of telerehabilitation in fibromyalgia. TRIAL REGISTRATION: PROSPERO CRD42022338200; https://tinyurl.com/322keukv.
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Dor Crônica , Fibromialgia , Telerreabilitação , Humanos , Fibromialgia/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Qualidade de VidaRESUMO
PURPOSE: The objective of this study was to clarify the clinical value of the posterior cruciate ligament index (PCLI) in anterior cruciate ligament (ACL) rupture, to explore the relationship between the PCLI and course of disease, and to identify the influencing factors of the PCLI. METHODS: The PCLI was defined a quotient of the X (the tibial and femoral PCL attachments) and the Y (the maximum perpendicular distance from X to the PCL). A total of 858 patients were enrolled in this case-control study, including 433 patients with ACL ruptures who were assigned to the experimental group and 425 patients with meniscal tears (MTs) who were allocated to the control group. Some patients in the experimental group have collateral ligament rupture (CLR). Information, such as the patient's age, sex, and course of disease, was recorded. All patients underwent magnetic resonance imaging (MRI) preoperatively, and the diagnosis was confirmed with the aid of arthroscopy. The PCLI and the depth of the lateral femoral notch sign (LFNS) were calculated based on the MRI findings, and the characteristics of the PCLI were explored. RESULTS: The PCLI in the experimental group (5.1 ± 1.6) was significantly smaller than that in the control group (5.8 ± 1.6) (P < 0.05). The PCLI gradually decreased with time and was only 4.8 ± 1.4 in patients in the chronic phase (P < 0.05). This change was not due to the decrease in X but rather the increase in Y. The results also showed that the PCLI was not related to the depth of the LFNS or injuries of other structures in the knee joint. Furthermore, when the optimal cut-off point of the PCLI was 5.2 (area under the curve = 71%), the specificity and the sensitivity were 84% and 67%, respectively, but the Youden index was just 0.3 (P < 0.05). CONCLUSION: The PCLI decreases due to the increase in Y instead of the decrease in X with time, especially in the chronic phase. The change in X in this process may be offset during imaging. In addition, there are fewer influencing factors that lead to changes in the PCLI. Therefore, it can be used as a reliable indirect sign of ACL rupture. However, it is difficult to quantify the diagnostic criteria of the PCLI in clinical practice. Thus, the PCLI as a reliable indirect sign of ACL rupture is associated with the course of knee joint injury, and it can be used to describe the instability of the knee joint. LEVELS OF EVIDENCE: III.
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Lesões do Ligamento Cruzado Anterior , Traumatismos do Joelho , Ligamento Cruzado Posterior , Humanos , Ligamento Cruzado Posterior/lesões , Ligamento Cruzado Anterior/cirurgia , Estudos de Casos e Controles , Articulação do Joelho/cirurgia , Lesões do Ligamento Cruzado Anterior/diagnóstico , Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Traumatismos do Joelho/diagnóstico por imagem , Traumatismos do Joelho/patologia , Ruptura/diagnóstico por imagem , Ruptura/patologia , Imageamento por Ressonância Magnética/métodosRESUMO
There is unequal spatial distribution of resource endowment, population density, industrial structure, and economic development with diverse differences in labor, energy, and capital productivities in China. However, previous studies paid little attention to the determinants of CO2 transfers embodied in electricity trade. In this study, we use both the absolute and comparative advantage theories to reveal the determinants of embodied CO2 transfers through electricity trade within China. Results show that China's electricity sector has higher labor productivity but lower asset efficiency and energy productivity than that of mining and manufacturing sectors. The large-scale electricity trade alleviates the shortage of electricity supply in developed regions by outsourcing to the less-developed regions, reduces the unequal spatial distribution of coal and natural gas reserves, and changes CO2 flow embodied in power grid. Econometric analysis shows that coal reserve contributes to the increase of embodied CO2 emission, while natural gas reduces the embodied CO2 emission. The regional differences in the opportunity cost of labor productivity of non-electricity sector are the dominant factor of the embodied CO2 transfers through electricity trade within China, while asset efficiency and energy productivity are not significant in the regressions. Our findings could provide details about China's power grid expansion when confronting climate mitigation in the future.
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Dióxido de Carbono , Gás Natural , Dióxido de Carbono/análise , Indústrias , China , Carvão Mineral , Carbono/análiseRESUMO
Mass spectrometry technology is becoming an important tool for clinical analysis due to its high specificity, high sensitivity and high multi-component detection capability. The current applications of this technology are mainly in liquid chromatography-tandem mass spectrometry (LC-MS/MS), matrix-assisted laser desorptionionization time-of-flight mass spectrometry (MALDI-TOF-MS), inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography-mass spectrometry (GC-MS) and the related in vitro diagnostic kits. At present, the number of medical device (MD) based on mass spectrometry technology is growing rapidly, especially the number of LC-MS/MS and MALDI-TOF-MS registered MD products, and the standardization of relevant product quality requirements is also being effectively carried out. In general, clinical mass spectrometry equipment is still mainly imported, and the equipment price is relatively high. The development of mass spectrometry kits is mainly based on imported platforms, and domestic equipment is still in its infancy; the further promotion of clinical application of mass spectrometry also depends on the progress of the automation and standardization of the analysis procedure. To investigate the detection performance of mass spectrometry systems, it is necessary to fully consider the characteristics of mass spectrometry technology itself.
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Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Cromatografia Gasosa-Espectrometria de MassasRESUMO
Basic helix-loop-helix (bHLH) proteins are transcription factors (TFs) that have been shown to regulate anthocyanin biosynthesis in many plant species. However, the bHLH gene family in Populus deltoids has not yet been reported. In this study, 185 PdbHLH genes were identified in the Populus deltoids genome and were classified into 15 groups based on their sequence similarity and phylogenetic relationships. Analysis of the gene structure, chromosome location and conserved motif of the PdbHLH genes were performed by bioinformatic methods. Gene duplication analyses revealed that 114 PdbHLH were expanded and retained after WGD/segmental and proximal duplication. Investigation of cis-regulatory elements of PdbHLH genes indicated that many PdbHLH genes are involved in the regulation of anthocyanin biosynthesis. The expression patterns of PdbHLHs were obtained from previous data in two colored-leaf poplar (QHP and JHP) and green leaf poplar (L2025). Further analysis revealed that 12 candidate genes, including 3 genes (PdbHLH57, PdbHLH143, and PdbHLH173) from the subgroup III(f) and 9 gene from other groups, were positively associated with anthocyanin biosynthesis. In addition, 4 genes (PdbHLH4, PdbHLH1, PdbHLH18, and PdbHLH164) may be involved in negatively regulating the anthocyanin biosynthesis. These results provide a basis for the functional characterization of bHLH genes and investigations on the molecular mechanisms of anthocyanin biosynthesis in colored-leaf poplar.
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Populus , Antocianinas , Regulação da Expressão Gênica de Plantas , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Populus/genética , Populus/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
In mammals, extensive chromatin reorganization is essential for reprogramming terminally committed gametes to a totipotent state during preimplantation development. However, the global chromatin landscape and its dynamics in this period remain unexplored. Here we report a genome-wide map of accessible chromatin in mouse preimplantation embryos using an improved assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) approach with CRISPR/Cas9-assisted mitochondrial DNA depletion. We show that despite extensive parental asymmetry in DNA methylomes, the chromatin accessibility between the parental genomes is globally comparable after major zygotic genome activation (ZGA). Accessible chromatin in early embryos is widely shaped by transposable elements and overlaps extensively with putative cis-regulatory sequences. Unexpectedly, accessible chromatin is also found near the transcription end sites of active genes. By integrating the maps of cis-regulatory elements and single-cell transcriptomes, we construct the regulatory network of early development, which helps to identify the key modulators for lineage specification. Finally, we find that the activities of cis-regulatory elements and their associated open chromatin diminished before major ZGA. Surprisingly, we observed many loci showing non-canonical, large open chromatin domains over the entire transcribed units in minor ZGA, supporting the presence of an unusually permissive chromatin state. Together, these data reveal a unique spatiotemporal chromatin configuration that accompanies early mammalian development.
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Blastocisto/metabolismo , Montagem e Desmontagem da Cromatina , Cromatina/genética , Cromatina/metabolismo , Alelos , Animais , Linhagem da Célula/genética , Reprogramação Celular , Metilação de DNA , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Redes Reguladoras de Genes/genética , Genoma/genética , Histonas/metabolismo , Masculino , Camundongos , Sequências Reguladoras de Ácido Nucleico/genética , Análise de Célula Única , Transcriptoma/genética , Transposases/metabolismo , Zigoto/metabolismoRESUMO
Histone modifications are fundamental epigenetic regulators that control many crucial cellular processes. However, whether these marks can be passed on from mammalian gametes to the next generation is a long-standing question that remains unanswered. Here, by developing a highly sensitive approach, STAR ChIP-seq, we provide a panoramic view of the landscape of H3K4me3, a histone hallmark for transcription initiation, from developing gametes to post-implantation embryos. We find that upon fertilization, extensive reprogramming occurs on the paternal genome, as H3K4me3 peaks are depleted in zygotes but are readily observed after major zygotic genome activation at the late two-cell stage. On the maternal genome, we unexpectedly find a non-canonical form of H3K4me3 (ncH3K4me3) in full-grown and mature oocytes, which exists as broad peaks at promoters and a large number of distal loci. Such broad H3K4me3 peaks are in contrast to the typical sharp H3K4me3 peaks restricted to CpG-rich regions of promoters. Notably, ncH3K4me3 in oocytes overlaps almost exclusively with partially methylated DNA domains. It is then inherited in pre-implantation embryos, before being erased in the late two-cell embryos, when canonical H3K4me3 starts to be established. The removal of ncH3K4me3 requires zygotic transcription but is independent of DNA replication-mediated passive dilution. Finally, downregulation of H3K4me3 in full-grown oocytes by overexpression of the H3K4me3 demethylase KDM5B is associated with defects in genome silencing. Taken together, these data unveil inheritance and highly dynamic reprogramming of the epigenome in early mammalian development.
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Alelos , Metilação de DNA , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Inativação Gênica , Histonas/metabolismo , Lisina/metabolismo , Animais , Reprogramação Celular/genética , Imunoprecipitação da Cromatina , Ilhas de CpG/genética , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Feminino , Fertilização/genética , Genoma/genética , Histonas/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Masculino , Metilação , Camundongos , Oócitos/metabolismo , Regiões Promotoras Genéticas , Análise de Sequência de DNA , Iniciação da Transcrição Genética , Zigoto/metabolismoRESUMO
This publisher's note corrects the affiliation section in Appl. Opt.58, 9718 (2019)APOPAI0003-693510.1364/AO.58.009718.