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Blood composition is indicative of health-related traits such as immunity and metabolism. The use of molecular genetics to investigate alterations in these attributes in laying ducks is a novel approach. Our objective was to employ genome - wide association studies (GWAS) and haplotype - sharing analysis to identify genomic regions and potential genes associated with 11 blood components in Shaoxing ducks. Our findings revealed 35 SNPs and 1 SNP associated with low-density lipoprotein cholesterol (LDL) and globulin (GLB), respectively. We identified 36 putative candidate genes for the LDL trait in close proximity to major QTLs and key loci. Based on their biochemical and physiological properties, TRA2A, NPY, ARHGEF26, DHX36, and AADAC are the strongest putative candidate genes. Through linkage disequilibrium analysis and haplotype sharing analysis, we identified three haplotypes and one haplotype, respectively, that were significantly linked with LDL and GLB. These haplotypes could be selected as potential candidate haplotypes for molecular breeding of Shaoxing ducks. Additionally, we utilized a bootstrap test to verify the reliability of GWAS with small experimental samples. The test can be accessed at https://github.com/xuwenwu24/Bootstrap-test.
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Patos , Estudio de Asociación del Genoma Completo , Haplotipos , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Animales , Patos/genética , Sitios de Carácter Cuantitativo/genética , Polimorfismo de Nucleótido Simple/genética , Desequilibrio de Ligamiento , Femenino , LDL-Colesterol/sangre , LDL-Colesterol/genéticaRESUMEN
In animals, evolutionarily conserved Polycomb repressive complex 2 (PRC2) catalyzes histone H3 lysine 27 trimethylation (H3K27me3) and PRC1 functions in recruitment and transcriptional repression. However, the mechanisms underlying H3K27me3-mediated stable transcriptional silencing are largely unknown, as PRC1 subunits are poorly characterized in fungi. Here, we report that in the filamentous fungus Magnaporthe oryzae, the N-terminal chromodomain and C-terminal MRG domain of Eaf3 play key roles in facultative heterochromatin formation and transcriptional silencing. Eaf3 physically interacts with Ash1, Eed, and Sin3, encoding an H3K36 methyltransferase, the core subunit of PRC2, and a histone deacetylation co-suppressor, respectively. Eaf3 co-localizes with a set of repressive Ash1-H3K36me2 and H3K27me3 loci and mediates their transcriptional silencing. Furthermore, Eaf3 acts as a histone reader for the repressive H3K36me2 and H3K27me3 marks. Eaf3-occupied regions are associated with increased nucleosome occupancy, contributing to transcriptional silencing in M. oryzae. Together, these findings reveal that Eaf3 is a repressive H3K36me2 reader and plays a vital role in Polycomb gene silencing and the formation of facultative heterochromatin in fungi.
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Proteínas Fúngicas , Silenciador del Gen , Heterocromatina , Histonas , Histonas/metabolismo , Histonas/genética , Heterocromatina/metabolismo , Heterocromatina/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Metilación , Regulación Fúngica de la Expresión Génica , Complejo Represivo Polycomb 2/metabolismo , Complejo Represivo Polycomb 2/genética , Nucleosomas/metabolismo , Proteínas del Grupo Polycomb/metabolismo , Proteínas del Grupo Polycomb/genética , Lisina/metabolismoRESUMEN
The plant hormone jasmonate (JA) regulates plant growth and immunity by orchestrating a genome-wide transcriptional reprogramming. In the resting stage, JASMONATE-ZIM DOMAIN (JAZ) proteins act as main repressors to regulate the expression of JA-responsive genes in the JA signaling pathway. However, the mechanisms underlying de-repression of JA-responsive genes in response to JA treatment remain elusive. Here, we report two nuclear factor Y transcription factors NF-YB2 and NF-YB3 (thereafter YB2 and YB3) play key roles in such de-repression in Arabidopsis. YB2 and YB3 function redundantly and positively regulate plant resistance against the necrotrophic pathogen Botrytis cinerea, which are specially required for transcriptional activation of a set of JA-responsive genes following inoculation. Furthermore, YB2 and YB3 modulated their expression through direct occupancy and interaction with histone demethylase Ref6 to remove repressive histone modifications. Moreover, YB2 and YB3 physically interacted with JAZ repressors and negatively modulated their abundance, which in turn attenuated the inhibition of JAZ proteins on the transcription of JA-responsive genes, thereby activating JA response and promoting disease resistance. Overall, our study reveals the positive regulators of YB2 and YB3 in JA signaling by positively regulating transcription of JA-responsive genes and negatively modulating the abundance of JAZ proteins.
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Di- and tri-methylation of lysine 36 on histone H3 (H3K36me2/3) is catalysed by histone methyltransferase Set2, which plays an essential role in transcriptional regulation. Although there is a single H3K36 methyltransferase in yeast and higher eukaryotes, two H3K36 methyltransferases, Ash1 and Set2, were present in many filamentous fungi. However, their roles in H3K36 methylation and transcriptional regulation remained unclear. Combined with methods of RNA-seq and ChIP-seq, we revealed that both Ash1 and Set2 are redundantly required for the full H3K36me2/3 activity in Magnaporthe oryzae, which causes the devastating worldwide rice blast disease. Ash1 and Set2 distinguish genomic H3K36me2/3-marked regions and are differentially associated with repressed and activated transcription, respectively. Furthermore, Ash1-catalysed H3K36me2 was co-localized with H3K27me3 at the chromatin, and Ash1 was required for the enrichment and transcriptional silencing of H3K27me3-occupied genes. With the different roles of Ash1 and Set2, in H3K36me2/3 enrichment and transcriptional regulation on the stress-responsive genes, they differentially respond to various stresses in M. oryzae. Overall, we reveal a novel mechanism by which two H3K36 methyltransferases catalyze H3K36me2/3 that differentially associate with transcriptional activities and contribute to enrichment of facultative heterochromatin in eukaryotes. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-023-00127-3.
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Rice blast is a highly destructive crop disease that requires the interplay of three essential factors: the virulent blast fungus, the susceptible rice plant, and favorable environmental conditions. Although previous studies have focused mainly on the pathogen and rice, recent research has shed light on the molecular mechanisms by which the blast fungus and environmental conditions regulate host resistance and contribute to blast disease outbreaks. This review summarizes significant achievements in understanding the sophisticated modulation of blast resistance by Magnaporthe oryzae effectors and the dual regulatory mechanisms by which environmental conditions influence rice resistance and virulence of the blast fungus. Furthermore, it emphasizes potential strategies for developing blast-resistant rice varieties to effectively control blast disease.
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The timing of the developmental transition from the vegetative to the reproductive stage is critical for angiosperms, and is fine-tuned by the integration of endogenous factors and external environmental cues to ensure successful reproduction. Plants have evolved sophisticated mechanisms to response to diverse environmental or stress signals, and these can be mediated by hormones to coordinate flowering time. Phytohormones such as gibberellin, auxin, cytokinin, jasmonate, abscisic acid, ethylene, and brassinosteroids and the cross-talk among them are critical for the precise regulation of flowering time. Recent studies of the model flowering plant Arabidopsis have revealed that diverse transcription factors and epigenetic regulators play key roles in relation to the phytohormones that regulate floral transition. This review aims to summarize our current knowledge of the genetic and epigenetic mechanisms that underlie the phytohormonal control of floral transition in Arabidopsis, offering insights into how these processes are regulated and their implications for plant biology.
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Arabidopsis , Epigénesis Genética , Flores , Reguladores del Crecimiento de las Plantas , Flores/crecimiento & desarrollo , Flores/genética , Flores/fisiología , Reguladores del Crecimiento de las Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/fisiología , Regulación de la Expresión Génica de las PlantasRESUMEN
Rice production accounts for approximately half of the freshwater resources utilized in agriculture, resulting in greenhouse gas emissions such as methane (CH4) from flooded paddy fields. To address this challenge, environmentally friendly and cost-effective water-saving techniques have become widely adopted in rice cultivation. However, the implementation of water-saving treatments (WSTs) in paddy-field rice has been associated with a substantial yield loss of up to 50% as well as a reduction in nitrogen use efficiency (NUE). In this study, we discovered that the target of rapamycin (TOR) signaling pathway is compromised in rice under WST. Polysome profiling-coupled transcriptome sequencing (polysome-seq) analysis unveiled a substantial reduction in global translation in response to WST associated with the downregulation of TOR activity. Molecular, biochemical, and genetic analyses revealed new insights into the impact of the positive TOR-S6K-RPS6 and negative TOR-MAF1 modules on translation repression under WST. Intriguingly, ammonium exhibited a greater ability to alleviate growth constraints under WST by enhancing TOR signaling, which simultaneously promoted uptake and utilization of ammonium and nitrogen allocation. We further demonstrated that TOR modulates the ammonium transporter AMT1;1 as well as the amino acid permease APP1 and dipeptide transporter NPF7.3 at the translational level through the 5' untranslated region. Collectively, these findings reveal that enhancing TOR signaling could mitigate rice yield penalty due to WST by regulating the processes involved in protein synthesis and NUE. Our study will contribute to the breeding of new rice varieties with increased water and fertilizer utilization efficiency.
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Compuestos de Amonio , Oryza , Oryza/genética , Fitomejoramiento , Agricultura/métodos , Nitrógeno/metabolismo , Agua/metabolismo , Transducción de Señal , Compuestos de Amonio/metabolismo , Suelo/química , Fertilizantes/análisisRESUMEN
Objective To analyze the burden and changing trend of testicular cancer in China from 1990 to 2019.Methods Based on the 2019 Global Burden of Disease Database(GBD 2019),analyze the incidence,mortality,disability-adjusted life years(DALYs),years of life lost(YLLs),years lived with disability(YLDs)and their variation trend of testicular cancer in Chinese population from 1990 to 2019.Evaluating changes in age standardized rate(ASR)by calculating annual estimated percentage change(EAPC).According to the age grouping,analyze the age distribution characteristics of testicular cancer disease burden by age group.Results In 2019,the incident cases,deaths,age-standardized incidence rate,and age-standardized mortality rate of testicular cancer in China were 17.17×103,1.21×103,2.39/105,and 0.16/105,respectively.Compared to 1990,incident cases,deaths,and age-standardized incidence rate increased obviously in China,which was consistent with the global change trend,while the increase was higher than the global level.However,both Chinese and global age-standardized mortality rate showed a downward trend.From 1990 to 2019,DALYs,YLLs and YLDs of testicular cancer increased by 29.66%,9.83%and 720.91%respectively in China.The two age groups,0-15 years group and 30-35 years group,were with highest incidence of testicular cancer,while the highest disease burden of testicular cancer was 30-35 years.Conclusion From 1990 to 2019,the disease burden of testicular cancer in China showed an upward trend.Adolescents and young adults should be the priority population for screening and prevention due to their higher incidence and disease burden.
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Background and purpose:Exogenous bone morphogenetic protein 9(BMP9)inhibits the malignant progression of human breast cancer,but its expression is often abnormally low in breast cancer.In this study,we intended to explore the expression and role of epigenetically-modified histone lysine-specific demethylase 4A(KDM4A)in breast cancer,and to investigate the relationship between KDM4A and BMP9 and its possible regulatory mechanism.Methods:The expression of KDM4A in breast cancer and its relationship with BMP9 were analyzed by bioinformatics and verified by real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR)and Western blot.Chromatin immunoprecipitation(ChIP)verified the regulatory role of KDM4A on BMP9,and RNA stability experiments and CHX protein stability experiments verified the effect of KDM4A in BMP9 expression.Exogenous recombinant MDA-MB-231 cells transfected with KDM4A small interfering RNA(siKDM4A)or infected with siBMP9 adenovirus(Ad-siBMP9)were constructed using RNA interference technology and adenoviruses knocking down BMP9,and the migratory and invasive abilities of the cells were detected by scratch healing assay and transwell assay,respectively.Results:Bioinformatics analysis showed that the expression of KDM4A was significantly higher in breast cancer than in normal tissues,and there was a negative correlation between the expression of KDM4A and that of BMP9 in breast cancer;RTFQ-PCR and Western blot showed that KDM4A was highly expressed in different breast cancer cell lines,and the knockdown of KDM4A significantly up-regulated BMP9.ChIP experiment confirmed that KDM4A could be significantly enriched in the promoter region of BMP9 gene,reducing its histone lysine 36 position instead of position 4 methyl status,thus silencing the expression of BMP9.RNA stability assay and CHX protein stability assay confirmed that KDM4A had no significant effect on the mRNA of BMP9,but could affect its protein degradation.After knocking down KDM4A,the migration and invasion abilities of breast cancer cells MDA-MB-231 were significantly inhibited,and this effect could be partially reversed by knocking down BMP9.Conclusion:KDM4A is highly expressed in breast cancer and breast cancer cell MDA-MB-231,and can silence its expression by down-regulating the level of histone methylation in the promoter region of the BMP9 gene,as well as affecting the stability of BMP9 at the protein level rather than at the level of mRNA,and promoting the migration and invasion of breast cancer.
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Pattern-recognition receptors (PRRs) mediate basal resistance to most phytopathogens. However, plant responses can be cell type specific, and the mechanisms governing xylem immunity remain largely unknown. We show that the lectin-receptor-like kinase LORE contributes to xylem basal resistance in Arabidopsis upon infection with Ralstonia solanacearum, a destructive plant pathogen that colonizes the xylem to cause bacterial wilt. Following R. solanacearum infection, LORE is activated by phosphorylation at residue S761, initiating a phosphorelay that activates reactive oxygen species production and cell wall lignification. To prevent prolonged activation of immune signaling, LORE recruits and phosphorylates type 2C protein phosphatase LOPP, which dephosphorylates LORE and attenuates LORE-mediated xylem immunity to maintain immune homeostasis. A LOPP knockout confers resistance against bacterial wilt disease in Arabidopsis and tomatoes without impacting plant growth. Thus, our study reveals a regulatory mechanism in xylem immunity involving the reversible phosphorylation of receptor-like kinases.
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Arabidopsis , Receptores Mitogénicos , Fosforilación , Xilema/microbiología , Lectinas , Enfermedades de las Plantas , Inmunidad de la PlantaRESUMEN
Autophagy is a conserved degradation and recycling pathway in eukaryotes and is important for their normal growth and development. An appropriate status of autophagy is crucial for organisms which is tightly regulated both temporally and continuously. Transcriptional regulation of autophagy-related genes (ATGs) is an important layer in autophagy regulation. However, the transcriptional regulators and their mechanisms are still unclear, especially in fungal pathogens. Here, we identified Sin3, a component of the histone deacetylase complex, as a transcriptional repressor of ATGs and negative regulator of autophagy induction in the rice fungal pathogen Magnaporthe oryzae. A loss of SIN3 resulted in upregulated expression of ATGs and promoted autophagy with an increased number of autophagosomes under normal growth conditions. Furthermore, we found that Sin3 negatively regulated the transcription of ATG1, ATG13, and ATG17 through direct occupancy and changed levels of histone acetylation. Under nutrient-deficient conditions, the transcription of SIN3 was downregulated, and the reduced occupancy of Sin3 from those ATGs resulted in histone hyperacetylation and activated their transcription and in turn promoted autophagy. Thus, our study uncovers a new mechanism of Sin3 in modulating autophagy through transcriptional regulation. IMPORTANCE Autophagy is an evolutionarily conserved metabolic process and is required for the growth and pathogenicity of phytopathogenic fungi. The transcriptional regulators and precise mechanisms of regulating autophagy, as well as whether the induction or repression of ATGs is associated with autophagy level, are still poorly understood in M. oryzae. In this study, we revealed that Sin3 acts as a transcriptional repressor of ATGs to negatively regulate autophagy level in M. oryzae. Under the nutrient-rich conditions, Sin3 inhibits autophagy with a basal level through directly repressing the transcription of ATG1-ATG13-ATG17. Upon nutrient-deficient treatment, the transcriptional level of SIN3 would decrease and dissociation of Sin3 from those ATGs associates with histone hyperacetylation and activates their transcriptional expression and in turn contributes to autophagy induction. Our findings are important as we uncover a new mechanism of Sin3 for the first time to negatively modulate autophagy at the transcriptional level in M. oryzae.
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Histonas , Magnaporthe , Histonas/metabolismo , Magnaporthe/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , AutofagiaRESUMEN
Time to flowering (vegetative to reproductive phase) is tightly regulated by endogenous factors and environmental cues to ensure proper and successful reproduction. How endogenous factors coordinate with environmental signals to regulate flowering time in plants is unclear. Transcription factors ETHYLENE INSENSITIVE 3 (EIN3) and its homolog EIN3 LIKE 1 (EIL1) are the core downstream regulators in ethylene signal transduction, and their null mutants exhibit late flowering in Arabidopsis (Arabidopsis thaliana); however, the precise mechanism of floral transition remains unknown. Here, we reveal that FLOWERING LOCUS D (FLD), encoding a histone demethylase acting in the autonomous pathway of floral transition, physically associates with EIN3 and EIL1. Loss of EIN3 and EIL1 upregulated transcriptional expression of the floral repressor FLOWERING LOCUS C (FLC) and its homologs in Arabidopsis, and ethylene-insensitive mutants displayed inhibited flowering in an FLC-dependent manner. We further demonstrated that EIN3 and EIL1 directly bind to FLC loci, modulating their expression by recruiting FLD and thereafter removing di-methylation of lysine 4 on histone H3 (H3K4me2). In plants treated with 1-aminocyclopropane-1-carboxylic acid, decreased expression of FLD resulted in increased enrichment of H3K4me2 at FLC loci and transcriptional activation of FLC, leading to floral repression. Our study reveals the role of EIN3 and EIL1 in FLC-dependent and ethylene-induced floral repression and elucidates how phytohormone signals are transduced into chromatin-based transcriptional regulation.
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Proteínas de Arabidopsis , Arabidopsis , Proteínas de Unión al ADN , Histona Demetilasas , Factores de Transcripción , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Unión al ADN/metabolismo , Etilenos/metabolismo , Flores/genética , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas , Histona Demetilasas/metabolismo , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Objective To explore the performance of domestic and international large language models(LLMs)in the context of ques-tion banks for clinical examination knowledge.Methods The performance of six domestic or international LLMs,in the question banks with a set of 330 questions for intermediate-level of clinical medical laboratory technology were assessed.The differences in accuracy and consistency among the different LLMs were evaluated using chi-square tests,Fisher's exact tests and logistic regression.Results The accuracy results for the four English LLMs along with 95%confidence intervals(95%CI)were as follows:the accuracy rates of ChatGPT,BingAI,Claude and GPT-4 were demonstrated as 0.56(95%CI:0.527-0.601),0.61(95%CI:0.572-0.644),0.64(95%CI:0.607-0.678)and 0.80(95%CI:0.767-0.833)respectively,while the performance of Xinghuo and Tiangong yielded accuracy rates of 0.52(95%CI:0.479-0.561)and 0.45(95%CI:0.408-0.482)respectively.Using ChatGPT as the reference model,we found that the odds ratios(OR)of correct answers of BingAI,Claude and GPT-4 were 1.272(95%CI:1.020-1.588),1.397(95%CI:1.119-1.743)and 3.270(95%CI:1.904-2.729)respectively.The differences of LLMs performance were statistically significant(P<0.05)for all the three models.In terms of consistency,Tiangong and BingAI showed poor consistency,while GPT-4 appeared better.Conclusion A-mong the six LLMs,GPT-4 demonstrated the highest overall accuracy and consistency in each question category.
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Objective:To explore the feasibility of anastomosis between bladder and intestine of experimental rabbit by drag anastomosis.Methods:In this study 40 Japanese big-eared rabbits were randomly divided into two groups through random number table, the experimental group and the control group, each group with 20 rabbits. In the experimental group, the bladder neck was fixed to the catheter and then the catheter was drawn outward. With the traction of the catheter, the bladder neck was anastomosed with the distal intestinal tube by means of suture free. The control group was anastomosed by regular interrupted suture of bladder and intestine. The operation time, anastomosis time, intraoperative blood loss, postoperative urinary leakage rate and postoperative anastomotic healing of rabbits in the two groups were compared.Results:The operation time of the experimental group was shorter than that of the traditional interrupted suture anastomosis group [(33.26±2.79)min vs. (35.25±1.83)min, P=0.014]. The anastomosis time of the experimental group was significantly shorter than that of the traditional interrupted suture anastomosis group[(7.55±1.2)min vs. (8.65±1.03 min), P=0.005]. The intraoperative blood loss in the experimental group was similar to that in the control group[(6.47±2.41) ml vs. (6.75±1.83) ml, P=0.691]. The event of contrast media extravasation occurred in 2 of the 10 experimental rabbits after receiving cystography in the experimental group, and the urinary leakage rate was 20%(2/10). In the control group, contrast media extravasation occurred in 1 of the 9 experimental rabbits after receiving cystography, and the urinary leakage rate was 11.1%(1/9), and the difference of the two groups was not statistically significant ( P=0.348). Anastomotic healing score was (2.0±0.7) in the experimental group, and (2.1±0.74) in the control group ( P=0.767). Conclusions:The bladder-intestine drag-and-bond anastomosis technique, with significantly shorter anastomosis time, was feasible, easy and convenient. Our research provides an experimental and theoretical basis for the clinical application of drag-and-bond anastomosis technique in clinic.
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Objective To analyze the characteristics and current situation of pharmaceutical journals sponsored by institutions in China,so as to improve the utilization,quality and dissemination effect of pharmaceutical journals,provide a basis for scientific evaluation and journal quality management,and provide a reference for readers to choose core journals,focus on reading and submitting.Methods The data of pharmaceutical journals sponsored by domestic institutions in China were collected in the"China Science and Technology Journals Citation Report(Core Edition)"compiled by the Institute of Scientific and Technical Information of China in 2023.This paper analyzes the characteristics and current situation of pharmaceutical journals sponsored by institutions in China,and investigates the number,citation frequency,impact factor,and regional distribution of pharmaceutical journals included in the core catalog of science and technology.Results A total of 48 core journals of pharmaceutical science and technology sponsored by domestic institutions were retrieved,and the publication cycle was mainly monthly(52.08% ).The Chinese Pharmaceutical Association is the institution with the largest number of core journals(15);In terms of quantity,15 core pharmaceutical journals in Beijing ranked first,ranking 2nd to 4th:Shanghai(6),Hubei(4),Jiangsu(4);The average total citation frequency in Chongqing was 3123 times,and the average total citation frequency was the highest.Conclusion The distribution of core pharmaceutical journals shows obvious advantages in economically developed regions such as Beijing and Shanghai.The Chinese Pharmaceutical Association,China Pharmaceutical University and the Chinese Academy of Medical Sciences and other institutions have sponsored many pharmaceutical academic journals,with a relatively complete journal system and rich experience in running journals.
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The genome-wide DNA methylation assay was used to analyze the difference in methylation between the breeding and conservation populations of Shaoxing ducks. The methylation level of the breeding population was higher than that of the two conservation populations, and the proportion of CG methylation sites was the largest in the three populations, most of the methylation sites were located in the exon region. There were 1247 different methylation regions in the two populations (group A and B), and 927 different methylation regions in the two groups (group A and group C). The differential methylation regions of the three groups were evenly distributed in the gene and intergene regions. GO and KEGG enrichment analysis showed that the differentially expressed genes in the A and B groups were mainly involved in synaptic and cell connections and the signaling pathways were significantly enriched in cAMP and oxytocin signaling pathways. The results showed that the group C was significantly enriched in eight signaling pathways, including the cAMP signaling pathway and long-term enhancement, compared to the group A. There were thirty-five differentially methylated genes, including CACNA1C, GRIA1, GRIA2, GABBR2, PDE10A, BRAF, GRM5, CPEB3, FMn2, GABRB2, PTK2, and CNTN1. These genes were involved in the development and ovulation of ovaries and follicles and were closely related to the excellent production performance of the breeding population. In addition, ATP2B1, ATP2B2, and other genes related to eggshell quality were identified, which can be used as molecular markers to improve eggshell quality in the future.
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Development in higher organisms requires proper gene silencing, partially achieved through trimethylation of lysine 27 on histone H3 (H3K27me3). However, how the normal distribution of this modification is established and maintained and how it affects gene expression remains unclear, especially in fungi. Polycomb repressive complex 2 (PRC2) catalyses H3K27me3 to assemble transcriptionally repressed facultative heterochromatin and is crucial in animals, plants, and fungi. Here, we report on the critical role of an additional PRC2 subunit in the normal distribution of H3K27me3 occupancy and the stable maintenance of gene repression in the rice fungal pathogen Magnaporthe oryzae. P55, identified as an additional PRC2 subunit, is physically associated with core subunits of PRC2 and is required for a complete level of H3K27me3 modification. Loss of P55 caused severe global defects in the normal distribution of H3K27me3 and transcriptional reprogramming on the H3K27me3-occupied genes. Furthermore, we found that the Sin3 histone deacetylase complex was required to sustain H3K27me3 occupancy and stably maintain gene repression by directly interacting with P55. Our results revealed a novel mechanism by which P55 and Sin3 participate in the normal distribution of facultative heterochromatic modifications and the stable maintenance of gene repression in eukaryotes.
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Histonas , Complejo Represivo Polycomb 2 , Animales , Ascomicetos , Heterocromatina/genética , Histonas/metabolismo , Lisina/metabolismo , Distribución Normal , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Complejo Correpresor Histona Desacetilasa y Sin3/genética , Complejo Correpresor Histona Desacetilasa y Sin3/metabolismoRESUMEN
Epigenetic modification is important for cellular functions. Trimethylation of histone H3 lysine 4 (H3K4me3), which associates with transcriptional activation, is one of the important epigenetic modifications. In this study, the biological functions of UvKmt2-mediated H3K4me3 modification were characterized in Ustilaginoidea virens, which is the causal agent of the false smut disease, one of the most destructive diseases in rice. Phenotypic analyses of the ΔUvkmt2 mutant revealed that UvKMT2 is necessary for growth, conidiation, secondary spore formation, and virulence in U. virens. Immunoblotting and chromatin immunoprecipitation assay followed by sequencing (ChIP-seq) showed that UvKMT2 is required for the establishment of H3K4me3, which covers 1729 genes of the genome in U. virens. Further RNA-seq analysis demonstrated that UvKmt2-mediated H3K4me3 acts as an important role in transcriptional activation. In particular, H3K4me3 modification involves in the transcriptional regulation of conidiation-related and pathogenic genes, including two important mitogen-activated protein kinases UvHOG1 and UvPMK1. The down-regulation of UvHOG1 and UvPMK1 genes may be one of the main reasons for the reduced pathogenicity and stresses adaptability of the ∆Uvkmt2 mutant. Overall, H3K4me3, established by histone methyltransferase UvKMT2, contributes to fungal development, secondary spore formation, virulence, and various stress responses through transcriptional regulation in U. virens.
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Many over-wintering plants grown in temperate climate acquire competence to flower upon prolonged cold exposure in winter, through vernalization. In Arabidopsis thaliana, prolonged cold exposure induces the silencing of the potent floral repressor FLOWERING LOCUS C (FLC) through repressive chromatin modifications by Polycomb proteins. This repression is maintained to enable flowering after return to warmth, but is reset during seed development. Here, we show that embryonic FLC reactivation occurs in two phases: resetting of cold-induced FLC silencing during embryogenesis and further FLC activation during embryo maturation. We found that the B3 transcription factor (TF) ABSCISIC ACID-INSENSITIVE 3 (ABI3) mediates both FLC resetting in embryogenesis and further activation of FLC expression in embryo maturation. ABI3 binds to the cis-acting cold memory element at FLC and recruits a scaffold protein with active chromatin modifiers to reset FLC chromatin into an active state in late embryogenesis. Moreover, in response to abscisic acid (ABA) accumulation during embryo maturation, ABI3, together with the basic leucine zipper TF ABI5, binds to an ABA-responsive cis-element to further activate FLC expression to high level. Therefore, we have uncovered the molecular circuitries underlying embryonic FLC reactivation following parental vernalization, which ensures that each generation must experience winter cold prior to flowering.
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Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cromatina/genética , Cromatina/metabolismo , Frío , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismoRESUMEN
Objective:To investigate the characteristics of distribution and drug resistance of urinary bacteria in the mid-stream urine of patients with infectious stones.Methods:The retrospective study analyzed the clinical data of 254 patients with infectious stones in the First Affiliated Hospital of Guangzhou Medical University from September 2016 to September 2018. All patients were treated with PCNL. Overall, there were 101 male and 153 female patients, with the mean age of(51.5±12.3) years, and the mean stone burden of 1443.5(660.8, 2837.5) mm2. There were 58 (22.8%) patients with hypertension, 17(6.7%) patients with diabetes and 195(76.8%)with hydronephrosis. The mid-stream urine samples were obtained for bacterial culture and susceptibility test, and the results of urine culture and antimicrobial susceptibility were recorded and analyzed.Results:Of 254 patients involved in this study, 89(35.0%) were positive and 165 (65.0%) were negative for urinary bacterial culture of the mid-stream. The proportion of patients with positive urine bacterial culture of the mid-stream who had positive urine leucocytes, positive urine nitrite and postoperative pyrexia were 86.5%(77/89), 64.0%(57/89), 25.8%(23/89), respectively, which was higher than that of patients with negative urine bacterial culture of the mid-stream [50.3%(83/165), 14.5%(24/165), 14.5%(24/165), P<0.05]. Four teen kinds of bacteria were detected from the mid-stream urine, and the three bacteria with the highest detection rate in turn were Escherichia coli of 38.2%(34/89), Proteus mirabilis of 15.7%(14/89), and Pseudomonas aeruginosa of 11.2%(10/89). The results of this study showed that three common bacteria had high resistance to drug including Cefazolin, Cefuroxime, Cefuroxime ester, Ampicillin and Co-trimoxazole (all resistance rate>40%). The resistance rates of Escherichia coli and Pseudomonas aeruginosa to Ciprofloxacin and Levofloxacin were higher than or equal to 40%. The resistance rates of Escherichia coli and Proteus mirabilis to meropenem, imipenem, ertapenem, piperacillin/tazobactam and amikacin were all lower than 10%. In addition, the resistance rates of Escherichia coli to nitrofurantoin and tigecycline and Proteus mirabilis to tobramycin, aztreonam and cefoxitin were all less than 10%. The resistance rates of Pseudomonas aeruginosa to ceftazidime, cefepime, gentamicin and aztreonam were less than 10%. Conclusions:The highest detection rate of urinary bacteria in culture of the mid-stream with infectious stones are Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa, all of which showed high resistance to Ampicillin, Cotrimoxazole, and some cephalosporins. Escherichia coli and Pseudomonas aeruginosa showe high resistance to Ciprofloxacin and Levofloxacin, and all of the three bacteria have low resistance rates to some β-Lactamase inhibitor complex and carbapenems, suggesting a reference for clinical empirical medical treatment.