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Wnt signaling usually functions through a spatial gradient. Localized Wnt3a signaling can induce the asymmetric division of mouse embryonic stem cells, where proximal daughter cells maintain self-renewal and distal daughter cells acquire hallmarks of differentiation. Here, we develop an approach, same cell epigenome and transcriptome sequencing, to jointly profile the epigenome and transcriptome in the same single cell. Utilizing this method, we profiled H3K27me3 and H3K4me3 levels along with gene expression in mouse embryonic stem cells with localized Wnt3a signaling, revealing the cell type-specific maps of the epigenome and transcriptome in divided daughter cells. H3K27me3, but not H3K4me3, is correlated with gene expression changes during asymmetric cell division. Furthermore, cell clusters identified by H3K27me3 recapitulate the corresponding clusters defined by gene expression. Our study provides a convenient method to jointly profile the epigenome and transcriptome in the same cell and reveals mechanistic insights into the gene regulatory programs that maintain and reset stem cell fate during differentiation. A localized Wnt3a signal has been shown to induce asymmetric division of mouse embryonic stem cells. Here the authors develop SET-seq, an approach to jointly profile epigenome and transcriptome in the same single cell and use it to provide mechanistic insights into the gene regulatory programs for maintaining and resetting stem cell fate during differentiation.

DNA topology is critical for regulating transcription and maintaining cellular homeostasis. Z-DNA is a left-handed DNA helix in regions with high transcriptional activity. Its physiological function remains poorly understood. Here, we demonstrate that oncoprotein MYC induces the formation of Z-DNA by recruiting the chromatin remodeler FACT, independent of RNA Polymerase II activity. FACT facilitates Z-DNA formation by remodeling H2A/H2B dimers within intact nucleosomes. Additionally, the phosphorylation of FACT regulates its liquid-liquid phase separation, promoting its efficient recruitment to chromatin by MYC. Through a genome-wide analysis and characterization of engineered Z-DNA promoters, we found that Z-DNA directly facilitates the loading of RNA Polymerase II, thereby promoting transcriptional activity. This study elucidates the molecular mechanisms of Z-DNA dynamics and emphasizes its functional importance in transcriptional regulation, providing insights into the role of left-handed DNA structures in chromatin biology and MYC-driven cancer. Z-DNA forms at highly active genes, but its function is unclear. Here, the authors show that MYC recruits FACT to promote Z-DNA formation within nucleosomes, enabling RNA Polymerase II loading and enhancing transcription, revealing a mechanistic role for Z-DNA in MYC-driven regulation.

MAT2B works together with MAT2A to synthesize S-Adenosyl methionine (SAM) as the primary methyl donor. MAT2B, despite lacking catalytic activity, exerts regulatory control over the enzymatic activity of MAT2A. In addition to the enzymatic activity regulation, we find that, in an NADP + -dependent manner, MAT2B binds and stabilizes MAT2A. Disruption of the cellular NADP + remodels the protein level of MAT2A. The pentose phosphatase pathway regulates the level of MAT2A protein through the interaction of NADP + with MAT2B. Additionally, MAT2B-MAT2A interaction regulates the mRNA m6A modification and stability. In liver tumors, the Mat2a mRNA level is elevated but the protein level is decreased by the restricted NADP + . Blocking the interaction between MAT2B and MAT2A by the keto diet can suppress liver tumor growth. These findings reveal that MAT2B is essential for regulating the protein levels of MAT2A and connecting SAM synthesis to mRNA m6A.

RNA sequencing has greatly facilitated gene expression studies but is weak in studying temporal RNA dynamics; this issue can be addressed by analyzing nascent RNAs. A famous method for nascent RNA analysis is metabolic labeling with noncanonic nucleoside followed by affinity purification, however, purification processes can always introduce biases into data analysis. Here, a chemical method for nascent RNA sequencing that avoids affinity purification based on acrylonitrile‐mediated uridine‐to‐cytidine (U‐to‐C) conversion (AMUC‐seq) via 4‐thiouridine (s4U) cyanoethylation is presented. This method converts s4U base‐pairing with guanine through the nucleophilic addition of s4U to acrylonitrile. The high reaction efficiency permits AMUC‐seq directly and efficiently to recover nascent RNA information from total RNAs. AMUC‐seq is validated by being used to detect mRNA half‐lives and investigating the direct gene targets of a G‐quadruplex stabilizer, which can be regarded as potential anticancer drug, in human cells. Thousands of direct gene targets of this drug are verified (these genes are significantly enriched in cancer such as SRC and HRAS). AMUC‐seq also confirms G‐quadruplex stabilization that impacts RNA polyadenylation. These results show AMUC‐seq is qualified for the study of temporal RNA dynamics, and it can be a promising strategy to study the therapeutic mechanism of transcription‐modulating drugs. 4‐thiouridine (s4U) cyanoethylation converts in the nascent RNA to cytidine in a base‐pairing manner, representing a promising strategy for enrichment‐free nascent RNA detection that further benefits transcriptome‐wide analysis of temporal RNA dynamics.

Background Hepatitis B Virus (HBV) contributes to liver carcinogenesis via various epigenetic mechanisms. The newly defined epigenetics, epitranscriptomics regulation, has been reported to involve in multiple cancers including Hepatocellular Carcinoma (HCC). Our previous study found that HBx, HBV encodes X protein, mediated H3K4me3 modification in WDR5-dependent manner to involve in HBV infection and contribute to oncogene expression. AlkB Homolog 5 (ALKBH5), one of epitranscriptomics enzymes, has been identified to be associated with various cancers. However, whether and how ALKBH5 is dysregulated in HBV-related HCC remains unclear yet. This study aims to investigate ALKBH5 function, clinical significance and mechanism in HBV related HCC (HBV-HCC) patients derived from Chinese people. Methods The expression pattern of ALKBH5 was evaluated by RT-qPCR, Western blot, data mining and immunohistochemistry in total of 373 HBV-HCC tissues and four HCC cell lines. Cell Counting Kit 8 (CCK8) assay, Transwell and nude mouse model were performed to assess ALKBH5 function by both small interference RNAs and lentiviral particles. The regulation mechanism of ALKBH5 was determined in HBx and WDR5 knockdown cells by CHIP-qPCR. The role of ALKBH5 in HBx mRNA N6-methyladenosine (m 6 A) modification was further evaluated by MeRIP-qPCR and Actinomycin D inhibitor experiment in HBV-driven cells and HBx overexpression cells. Result ALKBH5 increased in tumor tissues and predicts a poor prognosis of HBV-HCC. Mechanically, the highly expressed ALKBH5 is induced by HBx-mediated H3K4me3 modification of ALKBH5 gene promoter in a WDR5-dependent manner after HBV infection. The increased ALKBH5 protein catalyzes the m 6 A demethylation of HBx mRNA, thus stabilizing and favoring a higher HBx expression level. Furthermore, there are positive correlations between HBx and ALKBH5 in HBV-HCC tissues, and depletion of ALKBH5 significantly inhibits HBV-driven tumor cells’ growth and migration in vitro and in vivo . Conclusions HBx-ALKBH5 may form a positive-feedback loop to involve in the HBV-induced liver carcinogenesis, and targeting the loop at ALKBH5 may provide a potential way for HBV-HCC treatment.

Sexual reproduction begins with sperm–oocyte fusion to form a zygote, where chromatin undergoes dramatic reorganization to establish totipotency. Although nucleosomes- the basic units of eukaryotic chromatin and key epigenetic regulators- are extensively remodeled during early embryogenesis, their dynamic repositioning mechanisms and biological implications remain unclear. Here, we employed single-cell MNase sequencing (scMNase-seq) to map genome-wide nucleosome positioning and chromatin accessibility in individual mammalian embryos. We found that nucleosome positioning mirrored somatic cell patterns until the 4-cell stage, with nucleosome depletion and phasing at CTCF sites not fully established until morula formation. By integrating H3K4me3 localization and transcriptomic data, we revealed that nucleosome sparsity at transcription start sites (TSS) and flanking regions correlated with expression levels of genes critical for preimplantation development. Notably, these nucleosome-depleted regions likely serve as regulatory hubs influencing histone modification dynamics. Our study systematically delineates nucleosome reorganization principles during mammalian embryogenesis and provides a high-resolution resource for understanding chromatin remodeling in early development.

Hydrogen sulfide (H2S) is the main toxic pollutant emitted to the atmosphere from auto-coating wastewater. Its unorganized dispersion poses a health challenge for workers. Defining safe working distance, which transfers the H2S occupational exposure limit into industrial construction design regulation, would be a useful approach for reducing H2S exposure risk. Therefore, in this study, an H2S dispersion prediction, within 25 m, was performed by a computational fluid dynamics (CFD) method to explore the influence of temperature and wind speed on H2S dispersion. With the temperature changes from 288 K to 303 K, the H2S concentration at different observing points decreased. With wind speed changes from 2 m/s to 20 m/s, the plume layer structure was studied in the whole process. According to the H2S distribution characteristics, when the sedimentation tank treatment capacity is less than or equal to 10 m3/h, the safe working distance of H2S unorganized dispersion is 10 m. Hence, when there are workplaces within 10 m of the tank, closed measures should be taken for the sedimentation tank, or the manufacturer layout should be optimized to protect the environment and human health.

Nitrogen enters the terrestrial ecosystem through deposition. High nitrogen levels can affect physical and chemical properties of soil and inhibit normal growth and reproduction of forest plants. Nitrogen modulates the composition of soil microorganisms. Strigolactones inhibits plant branching, promotes root growth, nutrient absorption, and promotes arbuscular fungal mycelia branching. Plants are subjected to increasing atmospheric nitrogen deposition. Therefore, it is imperative to explore the relationship between strigolactone and nitrogen deposition of plants and abundance of soil microorganisms. In the present study, the effects of strigolactone on genetic responses and soil microorganisms of Torreya grandis , under simulated nitrogen deposition were explored using high-throughput sequencing techniques. T. grandis is a subtropical economic tree species in China. A total of 4,008 differentially expressed genes were identified in additional N deposition and GR24 treatment. These genes were associated with multiple GO terms and metabolic pathways. GO enrichment analysis showed that several DEGs were associated with enrichment of the transporter activity term. Both additional nitrogen deposition and GR24 treatment modulated the content of nutrient elements. The content of K reduced in leaves after additional N deposition treatment. The content of P increased in leaves after GR24 treatment. A total of 20 families and 29 DEGs associated with transporters were identified. These transporters may be regulated by transcription factors. A total of 1,402,819 clean reads and 1,778 amplicon sequence variants (ASVs) were generated through Bacterial 16S rRNA sequencing. Random forest classification revealed that Legionella, Lacunisphaera, Klebsiella, Bryobacter, and Janthinobacterium were significantly enriched in the soil in the additional N deposition group and the GR24 treatment group. Co-occurrence network analysis showed significant differences in composition of soil microbial community under different treatments. These results indicate a relationship between N deposition and strigolactones effect. The results provide new insights on the role of strigolactones in plants and composition of soil microorganisms under nitrogen deposition.

Despite its high economical and ornamental values, Torreya grandis , a dioecious non-timber coniferous species, has long been an underrepresented species. However, the advent and application of advanced genotyping technologies have stimulated its genetic research, making it possible to gain new insight into the genetic architecture of complex traits that may not be detected for model species. We apply an open-pollination (OP) mapping strategy to conduct a QTL mapping experiment of T. grandis , in which nearly 100 unrelated trees randomly chosen from the species’ natural distribution and their half-sib progeny are simultaneously genotyped. This strategy allows us to simultaneously estimate the recombination fractions and linkage disequilibrium (LD) coefficients between each pair of markers. We reconstruct a high-density linkage map of 4,203 SNPs covering a total distance of 8,393.95 cM and plot pairwise normalized LD values against genetic distances to build up a linkage-LD map. We identify 13 QTLs for stem basal diameter growth and 4 QTLs for stem height growth in juvenile seedlings. From the linkage-LD map, we infer the evolutionary history of T. grandis and each of its QTLs. The slow decay of QTL-related LDs indicates that these QTLs and their harboring genomic regions are evolutionarily relatively young, suggesting that they can better utilized by clonal propagation rather than through seed propagation. Genetic results from the OP sampling strategy could provide useful guidance for genetic studies of other dioecious species.

Background Currently, there are many studies researched the associations between maternal serum inflammatory indicators (i.e. ferritin, C-reactive protein [CRP], C3 and C4) and preterm birth (PTB). The results, however, are inconsistent. Therefore, the aim of this study was to estimate the relationship between maternal serum inflammatory indicators and PTB in a nested case-control (NCC)study. Methods A NCC study was conducted by Guangxi Birth Cohort Study which enrolled a total of 6203 pregnant women between 5 0/7 and 34 6/7 weeks of gestational age (wGA) from six cities in China between 2015 and 2016. There were 206women who delivered preterm (< 37 0/7 wGA), and 412 women who delivered term birth, those women were matched by maternal age, birth place, gender of infants, and wGA at blood collection. The inflammatory indicators were quantified by immunoturbidimetric methods. Results Highest quartile concentrations of all inflammatory indicators were determined versus median. After adjusting for maternal age, high levels of CRP (CRP > 16.60 mg/L) are related to the risk of PTB (OR = 2.16, 95% CI: 1.02–4.56, p  = 0.044) in the first trimester. The association of C3 was extremely related to those who delivered PTB (OR = 2.53, 95% CI: 1.14–5.64, p  = 0.023) in the first trimester. Moreover, no significant associations were found in C4 ( p  = 0.079) and ferritin ( p  = 0.067) between PTB. Conclusions Elevated concentrations of CRP and C3 in the first trimester were associated with increased risk of PTB. Inflammatory indicators may act a pivotal part in early diagnosis and prognosis of PTB.