Biology subjects

Zheng, X.

Publications and source records attributed to Zheng, X..

At least 73 records · Page 4Linked to original sources

bioRxiv2025

PD-1 signaling is essential for the early accumulation of HBV-specific CD8+ T cells during HBV infection

Background & AimsProgrammed cell death Protein 1(PD-1) is one of the key inhibitory receptors that regulates CD8 T cell exhaustion during chronic viral infection. However, the role of PD-1 in modulating effector T cell differentiation and function during early phase of hepatitis B virus (HBV) infection remains poorly defined. MethodsUsing adoptive transfer of wild-type or PD-1 KO HBV-specific TCR transgenic (C93-TCRtg) CD8 T cells, flow cytometry, and transcriptome sequencing, we systematically profiled early PD-1 dynamics in splenic and intrahepatic T cells and evaluated how PD-1 deficiency shapes anti-HBV T cell responses in acute self-resolving (AR) and chronic (CH) HBV mouse models. ResultsAcute HBV infection induced sustained PD-1 upregulation on intrahepatic/splenic CD8 T cells, which predominantly exhibited an effector phenotype. PD-1 cells displayed enhanced proliferation, cytotoxicity, and effector cytokine production compared to PD-1- counterparts. Adoptive transfer of PD-1 KO C93-TCRtg CD8 T cells resulted in significantly impaired early expansion in both spleen and liver during acute infection, accompanied by reduced granzyme B expression while maintaining IFN-{gamma}, TNF-, or IL-2 production. Transcriptomic analysis revealed that PD-1 deficiency was associated with the upregulation of apoptosis gene signatures. In chronic HBV infection, PD-1 KO cells failed to expand long-term and exhibited exacerbated exhaustion evidenced by a loss of IFN-{gamma} production. ConclusionsPD-1 is essential for the early expansion and survival of HBV-specific CD8 T cells during acute infection and does not suppress their effector cytokine function. Its absence impairs proliferation and promotes exhaustion of HBV-specific CD8 T cell in chronic infections. Impact and implicationsOur study redefines PD-1s role in acute HBV infection. Rather than merely constraining effector function, PD-1 is essential for the early expansion and survival of HBV-specific CD8+ T cells, acting as a safeguard against activation-induced apoptosis. The context-dependent functions position PD-1 as a critical rheostat calibrating the magnitude and quality of the antiviral CD8+ T cell response, with significant implications for immunotherapeutic strategies targeting this pathway in hepatitis B.

immunology↗

bioRxiv2025

Mitochondrial CircRNA CircMT-RNR2 Safeguards Antioxidant Defense to Support Fibroblast Functions in Wound Repair

Diabetic foot ulcers (DFUs) are a debilitating diabetes complication in which mitochondrial dysfunction and oxidative stress are prominent but mechanistically unresolved features. Here, we identify the mitochondria-encoded circular RNA circMT-RNR2 as a novel modulator of mitochondrial redox homeostasis in human skin wound healing. CircMT-RNR2 is reduced in DFU patient tissue and diabetic mouse wounds, enriched in dermal fibroblasts, and localized to mitochondria. Its loss impairs fibroblast proliferation, migration, extracellular matrix production, and contraction by destabilizing the mitochondrial antioxidant protein PRDX3, leading to elevated oxidative stress, mitochondrial damage, and mitophagy. In murine and human ex vivo wound models, circMT-RNR2 knockdown delays healing, whereas overexpression accelerates repair and boosts antioxidant defenses. These findings position circMT-RNR2 as a mitochondrial guardian of skin healing and a promising therapeutic target for DFUs. One Sentence SummaryCircMT-RNR2, a mitochondria-encoded circular RNA suppressed in diabetic foot ulcers, promotes fibroblast function and maintains mitochondrial redox balance via stabilization of the antioxidant protein PRDX3, offering a promising therapeutic target for chronic wound repair.

molecular biology↗

bioRxiv2025

Combining Selenocystine Based Fluorescence Assay with Structural Prediction for Enhanced Detection and Analysis of Cystine Stone Pathology

BackgroundCystine stones, a rare but recurrent type of kidney stones, primarily result from cystinuria, an inherited disorder caused by mutations in the genes SLC3A1 and SLC7A9, which encode renal cystine transporters. These mutations impair cystine reabsorption, resulting in elevated urinary cystine concentrations and stone formation. Current diagnostic methods are limited, particularly for detecting molecular-level dysfunctions. We aimed to develop a nonradioactive method for functional assessment of cystine transporters and mutation-specific pathologies. MethodsWe designed an innovative diagnostic approach combining a selenocystine-based fluorescence assay with structural predictions using AlphaFold to rapidly and accurately assess cystine transporter function and the molecular impacts of genetic mutations. ResultsOur assay demonstrated comparable transport efficiencies of cystine and selenocystine by the SLC3A1/SLC7A9 complex, and effectively differentiated mild, moderate, and severe functional impairments associated with known clinical mutations, including A354T and P482L. Structural modeling further provided mechanistic insights into mutation-induced dysfunctions. ConclusionThis integrated approach--combining a sensitive selenocystine fluorescence assay with AI-powered structural analysis--enables rapid, precise diagnosis of cystinuria variants and delivers mechanistic insights for personalized therapeutic strategies.

genetics↗

bioRxiv2025

KICDB: A Causality-Oriented Multi-Omics Database for Kinase Inhibitor-Induced Cardiotoxicity

BackgroundKinase inhibitors (KIs) are mainstays of targeted cancer therapy, but their clinical utility is frequently limited by cardiotoxicity. A systematic resource to explore the underlying causal mechanisms is urgently needed. MethodsWe present the KICDB (Kinase Inhibitor Cardiotoxicity Database), a comprehensive and interactive web server. KICDB is built upon a framework integrating large-scale transcriptomics meta-analysis with causal inference. ResultsThis database centralizes the findings from a comprehensive meta-analysis of 26 kinase inhibitors (KIs) across 7 studies (n=5291) identified 8,907 significant gene expression changes in human cardiomyocytes. To establish causality, we performed a two-pronged Mendelian randomization (MR) analysis testing hundreds of downstream genes and a panel of 43 key kinase proteins against 46 cardiovascular outcomes. This large-scale analysis revealed 26 significant causal associations, implicating novel molecular mediators in KI-induced cardiotoxicity. ConclusionsKICDB serves as a valuable and accessible platform for the cardio-oncology community. By integrating transcriptomic signatures with causal inference data, the database empowers researchers to formulate mechanistic hypotheses, accelerate biomarker validation, and guide the design of future cardioprotective strategies. URL: https://zhang-lab-database.shinyapps.io/KICDB/ Key PointsO_LIWe developed KICDB, a comprehensive and publicly accessible web server, to systematically investigate the causal mechanisms of KI-induced cardiotoxicity. C_LIO_LIKICDB integrates a large-scale meta-analysis of transcriptomic data from 26 KIs with a robust Mendelian randomization (MR) framework to move beyond correlation and infer causality. C_LIO_LIThe analysis identified 8,907 significant gene expression changes and 26 significant causal associations between KI-associated genes and 46 cardiovascular outcomes. C_LI

bioinformatics↗

bioRxiv2025

Visualising sub-second dynamics of nanoparticle extravasation in vivo

Altered vascular integrity is a hallmark for many diseases. Monitoring vascular permeability, including its extent and underlying transport pathways, is thus important for advancing our understanding of disease mechanisms towards innovative diagnosis and treatment. Here we show real-time fluorescence imaging using lanthanide-based upconversion nanoparticles as contrast agents to visualise subtle changes to vascular permeability in vivo. Based on simultaneous confocal imaging of the vasculature alongside single particle tracking in the wide-field at video rate, we performed high-throughput surveillance across live zebrafish larvae to pinpoint locations of potential nanoparticle extravasation, achieving superior sensitivity and specificity over conventional fluorescent dyes. Further analyses of the sub-second dynamics of individual nanoparticle extravasation events unveiled distinct characteristics to distinguish between transcellular and paracellular transport. We applied the technique to evaluate the blood-brain barrier (BBB) in zebrafish larvae at different developmental stages, and potential BBB perturbation strategy via nanoparticle functionalisation with polysorbates. Significantly increased BBB penetration by 36.5 folds was shown for the functionalised particles compared to phospholipid-coated particles, attributed to enhanced transcellular crossing. The technique is readily applicable to monitoring vascular integrity and investigating endothelial transport for improved understanding of vascular biology, facilitating advanced research in disease diagnostics and drug delivery towards translation.

biophysics↗

bioRxiv2025

Myocyte Enhancer Factor 2A Orchestrates Vascular Redox Homeostasis via Direct Transcriptional Activation of SIRT1

Myocyte enhancer factor 2A (MEF2A), a transcription factor implicated in coronary artery disease, remains unexplored in vascular redox regulation. To address this gap and overcome limitations of current antioxidant therapies, we investigated MEF2As role in oxidative defense using human umbilical vein endothelial cells (HUVECs) and murine models. Adenoviral vectors encoding MEF2A-specific shRNA or mRNA were employed to silence or overexpress MEF2A in HUVECs. For in vivo validation, endothelial-targeted MEF2A knockdown was achieved via AAV1-shRNA delivery in mice fed a high-fat diet. Systemic redox status was assessed by measuring reactive oxygen species (ROS), glutathione homeostasis (GSH/GSSG ratio), NADH/NAD+ balance, mitochondrial membrane potential ({Delta}{Psi}m), and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Mechanistic insights were derived from immunofluorescence, qPCR, western blotting, and dual-luciferase reporter assays. MEF2A silencing induced redox imbalance, characterized by elevated ROS, reduced GSH/GSSG ratio, and {Delta}{Psi}m collapse. Conversely, MEF2A overexpression synergized with SIRT1 to restore glutathione pools, maintain NAD+ homeostasis, and suppress ROS under oxidative stress. Chromatin immunoprecipitation confirmed direct MEF2A binding to two cis-elements in the SIRT1 promoter, driving transcriptional activation. In vivo, MEF2A-deficient mice exhibited amplified vascular oxidative damage, including elevated DNA damage marker (8-OHdG) and ROS levels. Downregulation of SIRT1/PGC-1 in MEF2A silenced cells was verified in vivo. Our findings establish MEF2A as a master regulator of endothelial redox defense via the SIRT1-PGC-1 axis, offering a mechanistic foundation for targeting oxidative cardiovascular disorders. This work suggests pharmacological MEF2A activation as a novel strategy for precision antioxidant therapy in vascular medicine.

molecular biology↗

bioRxiv2025

Pluripotent stem cell-derived siTNK cells attack tumors via a synthetic CD8-CD28 TCR complex

Tumor-associated antigen-specific T cell receptor (TCR)-engineered T cells offer a promising strategy for cancer therapy. Natural killer (NK) cells exhibit broad anti-tumor activity with low side effects but lack the capacity to recognize intracellular antigens. Here, we found that the human pluripotent stem cell (hPSC)-derived iNK cells, unlike tissue-isolated NK cells, expressed all four CD3 subunits at the transcriptome level. We introduced a synthetic gene-expressing complex (SCOTR), encoding a tumor antigen- specific TCR, CD8 coreceptor, and CD28 costimulatory molecule, into hPSCs to generate SCOTR-hPSCs. The SCOTR-hPSCs gave rise to abundant synthetic TCR complex-expressing iNK (siTNK) cells via an organoid induction method. These siTNK cells showed HLA-dependent, antigen-specific cytotoxicity against tumor cells and significantly suppressed tumor growth in tumor xenograft animal models, while also preserving universal non-specific tumor-killing activity. Collectively, siTNK cells, as hPSC-derived hybrid cells with dual features of adaptive T and inherent NK cells, offer an artificial cell source for human immunotherapies.

immunology↗

bioRxiv2025

miRNA/mRNA analysis of increased TGF-β pathways drive epithelial-mesenchymal transition and regulatory T cell differentiation

Chlamydia trachomatis genital tract infection is linked to severe reproductive complications in women, including ectopic pregnancy, infertility, and adverse pregnancy outcomes. Mouse models of infection suggest that chlamydia-induced dysregulation of microRNAs (miRNAs) can drive harmful cytokine responses, pathogenic epithelial-mesenchymal transition (EMT), and fibrosis. To investigate these mechanisms in humans, we profiled miRNA and mRNA expression in endometrial biopsies from women with endometrial infection (Endo+) and compared them to profiles from women with cervix-only infection (Endo-) or no infection. Ingenuity Pathway Analysis (IPA) revealed that Endo+ tissues had upregulated genes associated with innate and adaptive immune response pathways, as well as EMT regulation, while downregulated genes were linked to cell cycle control. An integrative miRNA-mRNA analysis, which combined a review of published miRNA regulation in human infections and immune responses with IPAs miRNA target filter, identified differentially expressed miRNAs that modulate these pathways in the endometrium of Endo+ women. Functional annotation of these miRNAs showed a predominance of downregulated miRNAs that typically suppress EMT and regulatory T cell (Treg) differentiation, along with miRNAs that usually enhance Th17 responses. Comparisons with previously identified mRNA pathways in blood samples from women with endometrial Chlamydia infection indicated that alterations in TGF-{beta} signaling and EMT were specific to the endometrium. Overall, the miRNA-mRNA interactions inferred from Endo+ tissue suggest increased activity in TGF-{beta} pathways that promote enhanced EMT and Treg differentiation, while reducing Th17 activation. These changes highlight a dual potential for promoting tissue scarring while dampening inflammatory responses that could otherwise limit infection.

genomics↗

bioRxiv2025

UniCure: A Foundation Model for Predicting Personalized Cancer Therapy Response

Predicting drug efficacy across diverse patient contexts remains a major challenge in oncology, as models trained on cancer cell lines often fail to capture patient-specific biology. Emerging biological foundation models and patient-derived technologies offer a promising solution. Here, we present UniCure, the first pre-trained foundation model integrating both omics and chemical foundation models (UCE and Uni-mol) to predict transcriptomic responses to drugs across diverse cellular and tissue contexts, enabling personalized cancer therapy and drug prioritization at the individual level. Rather than encoder/decoder used in traditional models, UniCure utilizes parameter-efficient fine-tuning (PEFT) techniques for optimizing the training process, a novel FlexPert module for modeling flexible drug-cell interactions, and a Maximum Mean Discrepancy (MMD) loss for learning unpaired data. Trained on over 1.8 million perturbation RNA-seq profiles over 22,000 compounds, 166 cell types, and 24 tissues, UniCure achieves high accuracy in predicting both dose-dependent responses and drug combination effects, demonstrating strong generalization across bulk and single-cell transcriptomic data. In particular, fine-tuning on our patient-derived tumor-like clusters and real-world data of 800 profiles enables UniCure to generate individualized therapeutic predictions on patients tissue samples. In addition, UniCure enables patient stratification based on the predicted drug responses, providing a new way for subtyping patients. UniCures drug prioritization was validated across over 1000 patients from pan-cancer cohorts and supported by experiments of candidate therapeutics. By enabling the potential to screen millions of compounds per patient at scale, UniCure represents a biologically grounded tool that could advance personalized precision oncology and accelerate drug discovery.

bioinformatics↗

bioRxiv2025

JiSuJi, a virtual muscle for small animal simulations, accurately predicts force from naturalistic spike trains

Physics-based simulators for neuromechanical control of virtual animals have the potential to significantly enhance our understanding of intricate structure-function relationships in neuromuscular systems, their neural activity and motor control. However, a key challenge is the accurate prediction of the forces that muscle fibers produce based on their complex patterns of electrical activity ("spike trains") while preserving model simplicity for broader applicability. In this study, we present a chemomechanical, three-dimensional finite-element muscle model - JiSuJi (pronounced ji su j[i], meaning "ultrafast muscle" in Chinese) - that efficiently and accurately predicts muscle forces from naturalistic spike trains. The models performance is validated against songbird vocal muscles, a particularly fast and therefore challenging muscle type. Our results demonstrate that JiSuJi accurately predicts both isometric and non-isometric muscle forces across a variety of naturalistic neural activity patterns. JiSuJi furthermore outperforms state-of-the-art muscle simulators for accuracy, while maintaining computational efficiency. Simulating muscle behavior offers a promising approach for investigating the underlying mechanisms of neuro-muscular interactions and precise motor control, especially in the fast-contracting muscles of animal model systems.

neuroscience↗

bioRxiv2025

HSV-1 orchestrates host RAP80 ubiquitination by ICP0 and UL36USP to promote viral survival

Herpes simplex virus 1 (HSV-1) is a widespread human pathogen that establishes lifelong infections, ubiquitination is crucial for HSV - 1 to interact with the host and regulate its life activities. But the mechanisms of how HSV-1 dynamically modulates host proteins at different infection stages to promote its own survival remains challenging. Here we identified DNA damage response protein RAP80 as a critical target of HSV-1 ubiquitination enzymes ICP0 and UL36USP throughout HSV-1s infection cycle. In early stages, RAP80 inhibits HSV-1 transcription by directly binding to the viral genome, blocking viral protein ICP4 binding to transcription factors. This interaction is regulated by phase separation via an intricate interplay between RAP80 and ICP0/ICP4. As infection progresses, the viral E3 ligase ICP0 degrades RAP80, dissolving phase separation, and allowing the formation of a mature viral replication compartment. In late infection stages, RAP80 is deubiquitinated by the viral deubiquitinase UL36USP, which restores cellular homeostasis and promotes HSV-1 survival. This process involves modulating the R-loop-cGAS-apoptosis pathway. These findings underscore the dynamic interplay between viral and host factors and the complex mechanisms used by HSV-1 to subvert host defenses, offering practical implications for the future development of antiviral strategies.

molecular biology↗

bioRxiv2025

Central nervous system atlas of larval zebrafish constructed using the morphology of single excitatory and inhibitory neurons

Single-neuron morphology mapping is fundamental for deciphering brain architecture and function, yet in vertebrates it remains limited in spatial coverage and cell-type information. Here we present a nervous system-wide single-neuron morphology atlas of larval zebrafish with annotated excitatory/inhibitory identity and dendrite-axon polarity. The atlas comprises >20,000 reconstructed neurons from >13,400 animals, spanning the central and peripheral nervous system and representing [~]24.5% of the total excitatory and inhibitory neurons in the brain, all integrated into a common physical space with neuroanatomical parcellations. We define >500 excitatory and inhibitory neuronal morphotypes and construct putative inter-cell-type and interregional connectomes. Projection and morphotype analyses reveal distinct laterality and directionality biases and modular innervation patterns in excitatory and inhibitory neurons, while network analyses uncover fundamental connectivity motifs, hubs, and sensorimotor pathways. Accessible through custom-built interactive platform ZExplorer, this atlas provides a foundational resource for multimodal data integration, circuit analysis, computational modeling, and hypothesis-driven research.

neuroscience↗

bioRxiv2025

Embryonic Durotaxis: A Mechanical Framework for Understanding Cesarean Scar Pregnancy

Cesarean scar pregnancy (CSP) is an increasingly common complication associated with the rise in cesarean section rates, yet its underlying mechanisms remain poorly understood. In this study, we identified a stiffness gradient between healthy and scarred uterine tissues in both human cesarean samples and mouse uterine scar models. By employing gradient stiffness hydrogels, we demonstrated that mouse embryos and human trophoblast spheroids exhibit durotaxis, migrating preferentially toward stiffer areas. This migration occurs through three-dimensional complex behaviors--translation, swinging, and rolling--characterized by periodic patterns that align with cavity oscillations. Embryonic durotaxis is initiated from asymmetric adhesion forces and is driven by embryonic protrusive forces, generated from Marangoni-like tissue flows. The intrinsic cavity oscillations further amplify and sustain embryonic durotaxis. Finally, pharmacological inhibition of embryonic durotaxis significantly reduced CSP incidence in the mouse model. Our findings establish the concept of embryonic durotaxis, which may provide novel therapeutic avenues for CSP prevention.

developmental biology↗

bioRxiv2025

Breaking the barrier of human-annotated training data for machine-learning-aided plant research using aerial imagery

Machine learning (ML) can accelerate biological research. However, the adoption of such tools to facilitate phenotyping based on sensor data has been limited by: (1) the need for a large amount of human-annotated training data for each context in which the tool is used; and (2) phenotypes varying across contexts defined in terms of genetics and environment. This is a major bottleneck because acquiring training data is generally costly and time-consuming. This study demonstrates how a ML approach can address these challenges by minimizing the amount of human supervision needed for tool building. A case study comparing ML approaches that examine images collected by an uncrewed aerial vehicle was performed to determine the presence of panicles (i.e., "heading") across thousands of field plots containing genetically diverse breeding populations of two Miscanthus species. Automated analysis of aerial imagery enabled the identification of heading approximately nine times faster than in-field visual inspection by humans. Leveraging an Efficiently Supervised Generative and Adversarial Network (ESGAN) learning strategy reduced the requirement for human-annotated data by one to two orders of magnitude compared to traditional, fully supervised learning approaches. The ESGAN model learned the salient features of the dataset by using thousands of unlabeled images to inform the discriminative ability of a classifier so that it required minimal human-labeled training data. This method can accelerate the phenotyping of heading date as a measure of flowering time in Miscanthus across diverse contexts (e.g., in multi-state trials) and opens avenues to promote the broad adoption of ML tools. One-sentence summaryMachine learning approach accelerates plant phenotyping by reducing the need for large amounts of human-annotated data, enabling faster and more efficient detection of a plant trait using aerial imagery The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (https://academic.oup.com/plphys/pages/General-Instructions) is Sebastian Varela.

bioinformatics↗

bioRxiv2025

Dysproteostasis primes pancreatic epithelial state changes in KRAS-mediated oncogenesis

Pre-malignant transformation of pancreatic acinar cells by oncogenic Kras is dependent upon stochastic emergence of metaplastic cell states, through unknown mechanisms. We reveal that an early, transcriptionally-mediated effect of Kras is sporadic failure of proteostatic ER-phagy. Genetically-altered mice deficient in ER-phagy demonstrate that this event co-operates with Kras to drive acinar-ductal metaplasia (ADM) and subsequent cancer. Mechanistically, proteomics and high-resolution imaging uncover pathologic aggregation of a subset of ER proteins, including the injury marker REG3B, resulting from failure to physically interact with the ER-phagy receptor CCPG1. Spatial transcriptomics demonstrate that the appearance of sporadic intracellular aggregates upon Kras activation marks rare acinar cells existing in an injured, ADM-primed state. Importantly, engineered mutants of REG3B establish that aggregate formation is sufficient to directly engender this epithelial cell state. Pancreatic cancer can thus arise from stochastic pathologic protein aggregates that are influenced by and co-operate with an oncogene.

cancer biology↗

bioRxiv2025

Munc13-4 mediates tumor immune evasion by regulating the sorting and secretion of PD-L1 via exosomes

Tumor-derived extracellular vesicles primarily carry PD-L1 via exosomes, which interact with PD-1 receptors on T cells, impacting immune responses in the tumor microenvironment and beyond, leading to a more extensive immunosuppressive landscape. However, the mechanisms governing exosomal PD-L1 sorting and secretion remain elusive. In this study, we identified Munc13-4 as a crucial regulator of exosomal PD-L1 sorting and secretion. Deletion of Munc13-4 in breast tumors enhances T cell-mediated anti-tumor immunity, suppresses tumor growth, and improves the efficacy of immune checkpoint inhibitors. Our results illustrate how Munc13-4 collaborates with HRS, Rab27, and SNAREs to facilitate PD-L1 sorting and secretion via exosomes. The cryo-EM structure of the Munc13-4-Rab27a complex provide new insights into its role in exosome secretion. Importantly, we discovered that Munc13-4 has a novel role in sorting PD-L1 onto exosomes, which relies on the formation of a ternary complex with PD-L1 and HRS. In addition, IFN{gamma} stimulation modifies Munc13-4 and HRS, establishing a dynamic regulatory mechanism that enables tumor cells to adapt to immune pressure by modulating PD-L1 sorting. Using a specially designed peptide to disrupt the Munc13-4-PD-L1 interaction and impede PD-L1 sorting significantly enhances anti-tumor immunity and slows tumor growth in vivo. These results highlight the potential of targeting the Munc13-4-PD-L1 axis to suppress tumor immune evasion.

cell biology↗

bioRxiv2025

RamEx: An R package for high-throughput microbial ramanome analyses with accurate quality assessment

Microbial single-cell Raman spectroscopy (SCRS) has emerged as a powerful tool for label-free phenotyping, enabling rapid characterization of microbial diversity, metabolic states, and functional interactions within complex communities. However, high-throughput SCRS datasets often contain spectral anomalies from noise and fluorescence interference, which obscure microbial signatures and hinder accurate classification. Robust algorithms for outlier detection and microbial ramanome analysis remain underdeveloped. Here, we introduce RamEx, an R package specifically designed for high-throughput microbial ramanome analyses with robust quality control and phenotypic classification. At the core of RamEx is the Iterative Convolutional Outlier Detection (ICOD) algorithm, which dynamically detects spectral anomalies without requiring predefined thresholds. Benchmarking on both simulated and real microbial datasets--including pathogenic bacteria, probiotic strains, and yeast fermentation populations--demonstrated that ICOD achieves an F1 score of 0.97 on simulated datasets and 0.74 on real datasets, outperforming existing approaches by at least 19.8%. Beyond anomaly detection, RamEx provides a modular and scalable workflow for microbial phenotype differentiation, taxonomic marker identification, metabolic fingerprinting, and intra-population heterogeneity analysis. It integrates Raman-based species-specific biomarkers, enabling precise classification of microbial communities and facilitating functional trait mapping at the single-cell level. To support large-scale studies, RamEx incorporates C++ acceleration, GPU parallelization, and optimized memory management, enabling the rapid processing of over one million microbial spectra within an hour. By bridging the gap between high-throughput Raman-based microbial phenotyping and computational analysis, RamEx provides a comprehensive toolkit for exploring microbial ecology, metabolic interactions, and antibiotic susceptibility at the single-cell resolution. RamEx is freely available under the MIT license at https://github.com/qibebt-bioinfo/RamEx.

bioinformatics↗

bioRxiv2025

Targeting dCas9-SunTag to a susceptibility gene promoter is sufficient for CRISPR interference

Cassava production in sub-Saharan Africa is severely impacted by diseases. Most pathogens require interaction with host susceptibility factors to complete their life cycles and cause disease. Targeted DNA methylation is an epigenetic strategy to alter gene expression in plants and we previously reported that a zinc-finger fused to DMS3 could establish methylation at the promoter of MeSWEET10a, a bacterial susceptibility gene, and this resulted in decreased disease. Here, we attempt a similar strategy for cassava brown streak disease. This disease is caused by the ipomoviruses CBSV and UCBSV. These viruses belong to the family Potyviridae, which has been shown extensively to require host eIF4E-family proteins to infect plants and cause disease. We previously found that cassava plants with simultaneous knockout mutations in two eIF4E genes, nCBP-1 and nCBP-2, resulted in decreased susceptibility to CBSD. Here, we report successful simultaneous targeting of both promoters with methylation using a dCas9-DMRcd-SunTag system. However, in contrast to our previous work with MeSWEET10a, controls indicate that CRISPR interference is occurring in these lines and is sufficient for reduction of gene expression. Future research will use genetic crosses to segregate away the DNA methylation reagents and, if DNA methylation proves heritable, assess whether methylation alone is sufficient increase resistance to CBSD.

plant biology↗