Results 351-375 of about 1,000
  1. Accurate diagnostics are essential for disease control and elimination efforts. However, access to diagnostics for neglected tropical diseases (NTDs) is hindered by limited healthcare infrastructure in many NTD-endemic regions, as well as by reliance on time- and labor-intensive diagnostic methods, such as smear microscopy. New diagnostic tools that are portable, rapid, low-cost, and meet World Health Organization (WHO) sensitivity and specificity targets are urgently needed to accelerate NTD control and elimination programs. Here, we introduce the NTDscope, a portable microscopy platform that enables point-of-care imaging and automated detection of parasites and other pathogens in patient samples. The NTDscope builds on and extends the capabilities of the LoaScope, a device that turned the camera of a mobile phone into a microscope and used on-board image processing to automatically quantify Loa loa microfilariae burden in whole blood samples. The NTDscope replaces the mobile phone of the LoaScope with a system-on-module (SOM) that enables the integration of multiple imaging modalities in a single package designed to improve robustness and expand applications. In this work, we demonstrate use of the NTDscope as a portable brightfield, darkfield, and fluorescence microscope for samples including microfilariae and helminth eggs. We also show that the device can be used to quantify molecular assays, such as a lateral flow test and a CRISPR-Cas13a-based assay. The ability to combine diagnostic capabilities of conventional microscopy with molecular assays and machine learning in a single device could expand access to diagnostics for populations in NTD-endemic areas and beyond. Author summary Neglected tropical diseases (NTDs) impact one billion of the world’s most vulnerable individuals. Diagnostics are a necessary part of NTD disease control and elimination efforts, but identifying infected individuals remains a challenge. Here we present the NTDscope, a portable multi-contrast microscope designed to diagnose multiple NTDs at the point-of-care. We show that the NTDscope can be used to detect the parasitic worm Loa loa in videos of whole blood samples and parasitic eggs in images of urine and stool samples. The NTDscope can also be used to image thick blood smears in disposable capillaries and serves as a lateral flow assay reader. In addition to brightfield and darkfield imaging, fluorescence imaging on the device enables molecular assays based on CRISPR-Cas enzymes. This portable (<1 kg), field-friendly device—tested in Cameroon, Gabon, Côte d’Ivoire, and Bangladesh—has the potential to become a platform technology that addresses diagnostic needs for multiple NTDs and could serve as a key element of decentralized healthcare in the future.
    Date: 2025-03-18
    Authors: Díaz de León Derby M, Moussa ZL, Ng CF, Bhuiya AM, Cabrera JP, Banik D, Delahunt CB, Keller MD, Le Ny AM, Garcia-Villena J, Dacal E, Bermejo-Peláez D, Cuadrado D, Luengo-Oroz M, Nana Djeunga HC, Kamgno J, Djune Yemeli L, Pahl V, Davi SD, Zoleko Manego R, Ramharter M, Bogoch II, Coulibaly JT, Khatun A, Kabir M, Noor Z, Haque R, Switz NA, Friedman DH, D’Ambrosio MV, Fletcher DA.
    Ref: medRxiv
  2. Autophagy is a vital cellular quality control pathway that enables plants to adapt to changing environments. By degrading damaged or unwanted components, autophagy maintains cellular homeostasis. While the organismal phenotypes of autophagy-deficient plants under stress are well-characterized, the contribution of cell-type-specific autophagy responses to whole-plant homeostasis remains poorly understood. Here, we show that root hair-forming cells (trichoblasts) of Arabidopsis thaliana exhibit higher autophagic flux than adjacent non-hair cells (atrichoblasts). This differential autophagy is genetically linked to cell fate determination during early development. Mutants disrupting trichoblast or atrichoblast identity lose the autophagy distinction between these cell types. Functional analyses reveal that elevated autophagy in trichoblasts is essential for sodium ion sequestration in vacuoles—a key mechanism for salt stress tolerance. Disrupting autophagy specifically in trichoblasts impairs sodium accumulation and reduces plant survival under salt stress. Conversely, cell-type-specific complementation restores both sodium sequestration and stress tolerance. Our findings uncover a cell-type-specific autophagy program in root hairs and demonstrate how developmental cues shape autophagy to enhance stress resilience. This work establishes a direct link between cell identity, autophagy, and environmental adaptation in plants.
    Date: 2025-03-18
    Authors: Zhao J, Löfke C, Yeung KC, Chen Y, Dagdas Y.
    Ref: bioRxiv
  3. Abstract Introduction: Thyroid cancer, exhibits distinct histopathological and molecular profiles that dictate clinical behavior. Advances in next-generation sequencing have elucidated subtype-specific genomic and transcriptomic alterations, enabling the classification of papillary (PTC), follicular (FTC), medullary (MTC), and anaplastic thyroid carcinoma (ATC). Despite progress, a significant gap remains in systematically integrating transcriptomic signatures with clinically actionable outcomes across all subtypes, particularly in resolving intra-tumoral heterogeneity and linking molecular profiles to therapeutic responses. Objective : To harness AI-driven clustering to identify subtype-specific transcriptomic signatures using large-scale datasets, such as The Cancer Genome Atlas (TCGA). Method : Transcriptomic datasets from TCGA thyroid cancer cohort (PTC, FTC, MTC, ATC) were preprocessed. scRNA-seq data were integrated (Seurat, DoubletFinder, Harmony) for single-cell resolution. Unsupervised clustering identified molecular subtypes and DEGs (Wilcoxon rank-sum, false discovery rate). Machine learning (ML) models predicted outcomes (10-fold cross-validation, AUC-ROC). Clinical integration (Cox models, Kaplan-Meier) and validation (GEO, CRISPR, immunohistochemistry) confirmed signatures. Reproducible pipelines (GitHub) ensured consistency. Results : Transcriptomic datasets from TCGA thyroid cancer cohort (500 samples) were preprocessed (Q30 > 90%, alignment > 85%, DESeq2, ComBat). scRNA-seq integration (25,000 cells) identified 12 cell types, with ATC showing immunosuppressive myeloid cells (p < 0.001). Unsupervised clustering revealed four molecular subtypes and 1,250 DEGs (BRAF, RET, TP53, PTEN). ML models (random forest, SVM) achieved high accuracy (AUC-ROC: 0.92, 0.89), identifying a 50-gene signature. Clinical integration linked high-risk subtypes to poor survival (HR: 2.5, p < 0.001). Validation (GEO, CRISPR, IHC) confirmed signature robustness (AUC-ROC: 0.89–0.93). Reproducible pipelines were shared via GitHub. Conclusion : This study identified robust transcriptomic signatures and subtype-specific ecosystems in thyroid cancer, validated through computational clustering, ML, and functional assays. Thus, this study advances in precision oncology by linking molecular profiles to clinical outcomes, supported by reproducible pipelines and high-performance computing.
    Date: 2025-03-18
    Authors: Andrade LJdO, de Oliveira GCM, Bittencourt AMV, Andrade JCNC, Silva CP, de Oliveira LM.
    Ref: Research Square
  4. Compensatory endocytosis is crucial for the presynapse to maintain a functional pool of fusion-competent vesicles. Slow Clathrin-mediated endocytosis has been widely regarded as the primary mechanism of retrieval but this has been challenged by competing Clathrin-independent endocytic models, most notably sub-second ultra-fast endocytosis, reported to be predominant at physiological temperature. Here, we sought to resolve the salience of the respective endocytic modes by using a purely presynaptic preparation, the Xenapse, amenable to total internal reflection fluorescence microscopy (TIRFM). While the role of Clathrin is in dispute, Dynamin is widely acknowledged to figure as the scission protein at the invaginated vesicle neck. Hence, we labelled the endogenous Dynamin I with EGFP by CRISPR-Cas9 techniques and visualized single synaptic Dynamin-mediated scission events at very high temporal resolution. This revealed only a single slow mode of Dynamin-dependent retrieval with a half time of ∼ 9 seconds at physiological temperature. Cross-correlational analysis with fluorescently labelled Clathrin confirmed these Dynamin events to be Clathrin-dependent. We thereby affirm Clathrin-mediated endocytosis as the primary mode of compensatory retrieval.
    Date: 2025-03-18
    Authors: Krishnan S, Lehrich J, Tsytsyura Y, Glyvuk N, Duan J, Klingauf J.
    Ref: bioRxiv
  5. Glioblastoma (GBM) poses a formidable challenge to patients for several reasons. Given its grim prognosis, understanding the various mechanisms GBM tumors utilize to resist therapy is essential to improve patient outcomes. Using PubMed, this focused review identifies and characterizes five critical elements of GBM tumors that contribute to their resistance to treatment: DNA repair enzymes, temozolomide (TMZ) and radiation mechanisms, anti-apoptosis mechanisms, GBM tumor heterogeneity and its effects on the cell cycle. This review explores various challenges associated with GBM tumors, such as their resistance against standard treatments such as TMZ and radiation therapy (RT). We explore the importance of epigenetic reprogramming, genetic mutations critical for cell proliferation and tumor suppression, and the role of mismatch repair (MMR) processes that influence RT and immune response interplay as contributors to GBM resistance. In addition, this review highlights vital DNA repair enzymes such as O6-methylguanine-DNA methyltransferase (MGMT) and Alkylpurine-DNA N-Glycosylase (APNG), which repair DNA damage introduced by alkylating agents such as TMZ. The involvement of the NuRD complex, particularly CHD4, in regulating access to DNA repair enzymes. Recent advancements in understanding the transcriptional regulation of MGMT through NF-κB activity are examined. Further, we explore novel approaches, including using anticancer neural stem cells and targeting hexokinase 2 (HK2) with antifungal drugs. Examining critical elements of the GBM cell cycle, such as the role of CDK's, cyclin(s) and proliferation markers such as ki67, can also give us a foundation for identifying possible target proteins and kinases for cancer drugs. While targeting DNA repair enzymes, proteins, and regulatory elements shows promise in enhancing GBM treatment efficacy, we acknowledge the challenges, including potential side effects and the risk of secondary cancers. Future research should focus on leveraging personalized medicine approaches and emerging biotechnologies, such as CRISPR gene editing, to develop targeted therapies that can overcome resistance mechanisms of GBM and improve patient outcomes.
    Date: 2025-03-17
    Authors: Woitas T, Chakrabarti K, Mohabir A, Nukala M, Safiullah S.
    Ref: Preprints.org
  6. Summary: This essay examines CRISPR-Cas technology, highlighting its potential and limitations in gene editing. While CRISPR enables precise DNA modifications for treating genetic diseases, its in vivo application faces major hurdles: low editing efficiency, delivery challenges, and off-target effects. Homology-directed repair (HDR) is inefficient, delivery methods are complex, and unintended mutations pose risks. A quantum-like genetic computation hypothesis suggests that CRISPR functions within a non-linear, probabilistic framework, challenging conventional methodologies. Ethical concerns include safety, consent, and legal regulation. The essay argues for a new quantum-informed research approach, integrating holistic, non-invasive methods like holistic medicine and nutrition to balance genetic interventions with natural biological processes.
    Date: 2025-03-17
    Authors: Zhang RH.
    Ref: Preprints.org
  7. A bstract Background Medulloblastoma is the most common malignant brain tumor of childhood. The highest-risk tumors are driven by recurrent Myc amplifications (Myc-MB) and experience poorer outcomes despite intensive multimodal therapy. The Myc transcription factor defines core regulatory circuitry for these tumors and acts to broadly amplify downstream pro-survival transcriptional programs. Therapeutic targeting of Myc directly has proven elusive, but inhibiting transcriptional cofactors may present an indirect means of drugging the oncogenic transcriptional circuitry sustaining Myc-MB. Methods Independent CRISPR-Cas9 screens were pooled to identify conserved dependencies in Myc-MB. We performed chromatin conformation capture (Hi-C) from primary patient Myc-MB samples to map enhancer-promoter interactions. We then treated in vitro and xenograft models with CDK9/7 inhibitors to evaluate effect on Myc-driven programs and tumor growth. Results Eight CRISPR-Cas9 screens performed across three independent labs identify CDK9 as a conserved dependency in Myc-MB. Myc-MB cells are susceptible to CDK9 inhibition, which is synergistic with concurrent inhibition of CDK7. Inhibition of transcriptional CDKs disrupts enhancer-promoter activity in Myc-MB and downregulates Myc-driven transcriptional programs, exerting potent anti-tumor effect. Conclusions Our findings identify CDK9 inhibition as a translationally promising strategy for the treatment of Myc-MB. K ey P oints CDK9 is an intrinsic dependency in Myc-driven medulloblastoma Dual CDK9/7 inhibition disrupts Myc-driven transcriptional circuitry CDK9 inhibitors should be developed as pharmaceutical agents for Myc-MB I mportance of the S tudy Medulloblastoma is the most common malignant brain tumor of childhood, and outcomes for high-risk subgroups remain unsatisfactory despite intensive multimodal therapy. In this study, we pool multiple independent CRISPR-Cas9 screens to identify transcriptional cofactors such as CDK9 as conserved dependencies in Myc-MB. Using Hi-C from primary patient samples, we map Myc enhancer-promoter interactions and show that they can be disrupted using inhibition of transcriptional CDKs. CDK9 inhibitor treatment depletes Myc-driven transcriptional programs, leading to potent anti-tumor effect in vitro and prolongation of xenograft survival in vivo . With a large number of CDK9 inhibitory compounds now in clinical development, this study highlights the opportunity for clinical translation of these for children diagnosed with Myc-MB.
    Date: 2025-03-17
    Authors: Martin Sobral L, Walker FM, Madhavan K, Janko E, Donthula S, Balakrishnan I, Wang D, Pierce A, Haag MM, Carstens BJ, Serkova NJ, Foreman NK, Venkataraman S, Veo B, Vibhakar R, Dahl NA.
    Ref: bioRxiv
  8. Oncolytic virus (OV) therapy is a promising treatment for various tumors. However, in pancreatic ductal adenocarcinoma (PDAC), the high abundance of cancer-associated fibroblasts (CAFs) can limit OV therapy efficacy by impairing viral spread and anti-tumor immunity. We have previously shown that oncolytic reovirus infection of CAFs depends on expression of the reovirus entry receptor Junctional Adhesion Molecule A (JAM-A), which is not or lowly expressed in most PDAC CAFs. We propose that increasing JAM-A expression on CAFs will boost viral spread in a tumor. However, there are currently no known regulators of JAM-A expression. Therefore, we performed a genome-wide CRISPR/Cas9 knock-out screen to identify regulators of JAM-A expression. Ablation of the top negative regulator, Zinc Finger E-Box binding Homeobox 1 ( ZEB1 ), in pancreatic fibroblasts led to strong JAM-A upregulation. We show that ZEB1 directly regulates JAM-A expression by binding to the E-box regions located within the JAM-A promotor. Importantly, ZEB1 ablation increased the sensitivity of fibroblasts to reovirus infection and subsequent cell death. Our work provides a novel overview of genes regulating JAM-A expression and provides a rational approach of combining ZEB1 inhibition with reovirus therapy to target both CAFs and tumor cells in stroma-rich tumors such as PDAC.
    Date: 2025-03-17
    Authors: Dam N, Harryvan TJ, Dang H, Ioannidis G, Schmierer B, Hawinkels LJ, Kemp V.
    Ref: bioRxiv
  9. Over the last few centuries, advancements in plant breeding have revolutionized agriculture, driving significant increases in global food production. Polyploidy, the increase in chromosome copies, can positively affect plant performance and is assumed to have played a critical role in the domestication of crop plants. Polyploidy is thought to be primarily caused by sperm that, due to meiotic aberrations, deliver unreduced chromosome sets. We have recently identified an alternative pathway to polyploidization by demonstrating that polyspermy, the fertilization of an egg cell by more than one sperm, occurs in planta and results in viable triploid plants. Capitalizing on a novel high-throughput polyspermy detection tool, we have shown that polyspermy involving two pollen donors can generate plants with three parents, one mother and two fathers. This 3PaTec technology not only speeds up breeding processes through an instant combination of beneficial traits from three parents; it also allows selective polyploidization of the egg cell, thereby bypassing the central cell-derived embryo-nourishing endosperm, a major hybridization barrier. Here, we further explore the genetic and developmental factors influencing polyspermy and show that the frequency of polyspermy and triparental plant formation varies among ecotypes and depends on pollen availability, suggesting that polyspermy is an adaptive trait. Additionally, we extend the application of 3PaTec to crops by successfully generating triparental sugar beet in-field using a wind pollination strategy. Our findings highlight the potential of 3PaTec for major crop plants. This innovative breeding technology does not rely on genetic engineering, requiring minimal technical expertise and infrastructure. As a result, it is highly accessible to a wide range of users, contributing to the democratization of plant breeding by empowering individuals from all backgrounds to collaborate and contribute to developing resilient and sustainable crops.
    Date: 2025-03-17
    Authors: Joshi S, Beer CA, Mao Y, Thomas Baum T, Tekleyohans DG, Bubenheim C, Palovaara J, Czarnecki O, Nakel T, Groß-Hardt R.
    Ref: bioRxiv
  10. Immunocompetent and experimentally accessible alveolar systems to study human respiratory diseases are lacking. Here, we developed a single donor human induced pluripotent stem cell (iPSC)-derived Lung-on-Chip (iLoC) containing Type II and I alveolar epithelial cells, vascular endothelial cells, and macrophages in a microfluidic device that mimic lung 3D mechanical stretching and air-liquid interface. Imaging and scRNA-seq analysis revealed that the iLoC recapitulated cellular profiles present in the human distal lung. Infection of the iLoC with the human pathogen Mycobacterium tuberculosis (Mtb) showed that both macrophages and epithelial cells were infected and showed limited bacterial replication. Stochastically, large macrophage clusters containing necrotic core-like structure and Mtb replication were observed. A genetically engineered autophagy deficient iLoC revealed that after Mtb infection, macrophage necrosis was higher upon ATG14 deficiency without bacterial replication. Altogether, we report an autologous, genetically tractable human alveolar model to study lung diseases and therapies.
    Date: 2025-03-17
    Authors: Luk CH, Conway GL, Goh KJ, Fearns A, Rodriguez-Hernandez I, Day NJ, Athanasiadi N, D’Antuono R, Pellegrino E, Stucki JD, Hobi N, Gutierrez MG.
    Ref: bioRxiv
  11. 6-Thioguanine (6-TG), an FDA-approved antimetabolite drug, is widely used in the treatment of leukemia. Its cellular effects require metabolic activation and are regulated through interactions with various proteins such as NUDT15, which catalyzes the hydrolysis of the active 6-TG metabolites 6-thio-deoxyGTP (6-thio-dGTP) and 6-thio-GTP. Recent genome-wide CRISPR loss-of-function studies have identified another NUDIX hydrolase, NUDT5, as a crucial mediator of 6-TG toxicity. Here, we present the development and characterization of potent and selective NUDT5 degraders, guided by a cell-based assay screening strategy. These degraders, in conjunction with orthogonal CRISPR knock-out and reconstitution experiments, reveal a novel and unexpected, non-enzymatic role for NUDT5 in modulating the cellular response to 6-TG. Depletion of NUDT5 protein is antagonistic to NUDT15 inhibition, suggesting a distinct mode-of-action with potential implications for patient therapy.
    Date: 2025-03-17
    Authors: Marques AMC, Bauer LG, Nguyen T, Orta AG, Venne J, Cheng L, Balikci E, Tivon B, London N, Kubicek S, Huber KVM.
    Ref: bioRxiv
  12. ABSTRACT Background and Aims Gastrointestinal (GI) enterochromaffin (EC) cells are specialised sensors of luminal stimuli. They secrete most of the body’s serotonin (5-HT), and are critical for modulating GI motility, secretion, and sensation, while also signalling satiety and intestinal discomfort. The aim of this study was to investigate mechanisms underlying the regulation of human EC cells, and the relative importance of direct nutrient stimulation compared with neuronal and paracrine regulation. Methods Intestinal organoids from human duodenal biopsies were modified using CRISPR-Cas9 to specifically label EC cells with either the fluorescent protein Venus or the cAMP sensor Epac1-S. EC cells were purified by fluorescence-activated cell sorting for analysis by bulk RNA sequencing and liquid chromatography mass spectrometry peptidomics. The function of human EC cells was studied using single cell patch clamp, calcium and cAMP imaging and 5-HT ELISA assays. Results Human EC cells showed expression of receptors for nutrients (including GPR142 , GPBAR1, GPR119, FFAR2, OR51E1, OR51E2 ), gut hormones (including SSTR1,2&5 , NPY1R, GIPR ) and neurotransmitters ( ADRA2A , ADRB1 ). Functional assays revealed EC responses (calcium, cAMP and/or secretion) to a range of stimuli, including bacterial metabolites, aromatic amino acids and adrenergic agonists. Electrophysiological recordings showed that isovalerate increased action potential firing. Conclusions 5-HT release from EC cells controls many physiological functions and is currently being targeted to treat disorders of the gut-brain axis. Studying ECs from human organoids enables improved understanding of the molecular mechanisms underlying EC cell activation, which is fundamental for the development of new strategies to target 5-HT-related gut and metabolic disorders. Synopsis Human duodenal organoids expressing fluorescent proteins in enterochromaffin cells were used to study mechanisms underlying serotonin secretion. Different expression of key sensory receptors was identified by transcriptomic analysis, and validated by live cell second messenger imaging and secretion assays.
    Date: 2025-03-17
    Authors: Alcaino C, Guccio N, Miedzybrodzka EL, Quale JR, Davison A, Smith CA, Overington E, Santos-Hernández M, Tabbada M, Lu T, Hodge M, Bany-Bakar R, Kay R, Shaaban A, Imig C, Reimann F, Gribble FM.
    Ref: bioRxiv
  13. CRISPR-associated endoribonucleases (Cas RNases) cleave single-stranded RNA in a highly sequence-specific manner, by recognizing and binding to short RNA sequences known as direct repeats (DRs). Here we investigate the potential of exploiting Cas RNases for the regulation of target genes with one or more DRs introduced into the 3’ untranslated region, an approach we refer to as DREDGE ( d irect r epeat- e nabled d own-regulation of g ene e xpression). The DNase-dead version of Cas12a (dCas12a) was identified as the most efficient among 5 different Cas RNases tested and was subsequently evaluated in doxycycline-regulatable systems targeting either stably expressed fluorescent proteins or an endogenous gene. DREDGE performed superbly in stable cell lines, resulting in up to 90% downregulation with rapid onset, notably, in a fully reversible manner. Successful control of an endogenous gene with DREDGE was demonstrated in two formats, including one wherein both the DR and the transgene driving expression of dCas12a were introduced in one step by CRISPR-Cas. Our results establish DREDGE as an effective method for regulating gene expression in a targeted, highly selective, and fully reversible manner, with several advantages over existing technologies.
    Date: 2025-03-17
    Authors: Parikh SJ, Terron HM, Burgard LA, Maranan DS, Butler DD, Wiseman A, LaFerla FM, Lane S, Leissring MA.
    Ref: bioRxiv
  14. Stem cells are highly resistant to viral infection compared to their differentiated progeny, and this resistance is associated with stem cell-specific restriction factors and intrinsic interferon stimulated genes (ISGs). In HIV infection, proviral DNA has been detected in certain bone marrow hematopoietic stem cells, yet widespread stem cell infection in vivo is restricted. Intriguingly, exposing bone marrow stem cells to HIV in vitro led to viral replication selectively only in the CD34 - population, but not in the CD34 + cells. The mechanism dictating this CD34-based HIV restriction remained a mystery, especially since HIV has a capacity to antagonize restriction factors and ISGs. CD34 is a common marker of hematopoietic stem and progenitor cells. Here, we report the intrinsic antiviral properties of CD34. Expression of CD34 in HIV-1 producer cells results in the loss of progeny virion infectivity. Conversely, removal of CD34 using CRISPR/Cas9 knockout or stem cell differentiation cytokines promotes HIV-1 replication in stem cells. These results suggest that in addition to restriction factors and intrinsic ISGs, CD34 serves as a host innate protection preventing retrovirus replication in stem cells. Mechanistically, CD34 does not block viral entry, integration, and release. Instead, it becomes incorporated onto progeny virions, which inactivates virus infectivity. These findings offer new insights into innate immunity in stem cells, and highlight intriguing retrovirus-host interactions in evolution.
    Date: 2025-03-17
    Authors: He S, Haikerwal A, Tiwari S, Dabbagh D, Alam MZ, Yoon JL, Hetrick B, Han Y, Shan L, Lockhart C, Wu Y.
    Ref: bioRxiv
  15. Pennycress ( Thlaspi arvense ) is under development to be grown as a winter annual intermediate oil seed bioenergy crop in the Midwest during typical fallow periods. Crucial work remains to domesticate and optimize pennycress for incorporation into cropping systems and increasing resilience to rising temperatures. We found that increased planting density reduces biomass and swiftens time to flowering and maturity, which are features associated with shade avoidance responses. In controlled conditions, we found that pennycress elongates in response to foliar shade and increased ambient temperatures (20 °C to 28 °C). We applied the knowledge base from Arabidopsis thaliana to manipulate genes in the PHYB signaling pathway to simultaneously decrease the shade avoidance response during interseeding and tissue responses to elevated temperatures. Evaluation of CRISPR alleles of PIF7 shows that pif7 reduces organ elongation to competition and heat cues and retains a compact rosette when exposed to shade or elevated temperature and their combination. Crucially, yield and oil content were unaltered in pif7 and plants maintained earlier flowering in stress conditions. Furthermore, indicators of plant health, such as hue, chlorophyll indices, and root system architecture were improved between wild type and pif7 . This is evidence that plant architecture and physiological health can be uncoupled under competition and heat conditions, supporting our efforts to attenuate morphological responses to environmental cues. We propose this strategy to reduce SAR will improve pennycress performance at high densities, during interseeding establishment in standing crops, and in a warming climate.
    Date: 2025-03-17
    Authors: Jawahir V, Adam S, Griffiths M, Wesley T, Phippen W, Heller N, Borphukan B, Sanguinet K, Nusinow DA.
    Ref: bioRxiv
  16. RNA alternative splicing is a fundamental cellular process implicated in cancer development. Kaposi’s sarcoma-associated herpesvirus (KSHV), the etiological agent of multiple human malignancies, including Kaposi’s sarcoma (KS), remains a significant concern, particularly in AIDS patients. A CRISPR-Cas9 screening of matched primary rat mesenchymal stem cells (MM) and KSHV-transformed MM cells (KMM) identified key splicing factors involved in KSHV-induced cellular transformation. To elucidate the mechanisms by which KSHV-driven splicing reprogramming mediates cellular transformation, we performed transcriptomic sequencing, identifying 131 differential alternative splicing transcripts, with exon skipping as the predominant event. Notably, these transcripts were enriched in vascular permeability, multiple metabolic pathways and ERK1/2 signaling cascades, which play key roles in KSHV-induced oncogenesis. Further analyses of cells infected with KSHV mutants lacking latent genes including vFLIP, vCyclin and viral miRNAs, as well as cells overexpressing LANA, revealed their involvement in alternative splicing regulation. Among the identified splicing factors, FAM50A, a component of the spliceosome complex C, was found to be crucial for KSHV-mediated transformation. FAM50A knockout resulted in distinct splicing profiles in both MM and KMM cells, and significantly inhibited KSHV-driven proliferation, cellular transformation and tumorigenesis. Mechanistically, FAM50A knockout altered SHP2 splicing, promoting an isoform with enhanced enzymatic activity that led to reduced STAT3 Y705 phosphorylation in KMM cells. These findings reveal a novel paradigm in which KSHV hijacks host splicing machinery, specifically FAM50A-mediated SHP2 splicing, to sustain STAT3 activation and drive oncogenic transformation. Importance Kaposi’s sarcoma-associated herpesvirus (KSHV) causes cancers such as Kaposi’s sarcoma, particularly in AIDS patients. This study uncovers how KSHV hijacks a fundamental cellular process called RNA splicing to promote cancer development. We identified key splicing events that alter critical pathways involved in vascular permeability, metabolism, and oncogenic signaling, particularly ERK1/2 and STAT3. A specific protein, FAM50A, was found to be essential for KSHV-driven cancerous transformation. Removing FAM50A disrupted splicing, weakening cancer-promoting signals. These findings provide new insights into how viruses manipulate host cells to drive cancer and highlight RNA splicing as a potential target for future therapies.
    Date: 2025-03-17
    Authors: Sun S, Paniagua K, Ding L, Wang X, Huang Y, Flores MA, Gao S.
    Ref: bioRxiv
  17. ABSTRACT The rise of difficult-to-treat Mycobacterium abscessus infections presents a growing clinical challenge due to the immense arsenal of intrinsic, inducible and acquired antibiotic resistance mechanisms that render many existing antibiotics ineffective against this pathogen. Moreover, the limited success in discovery of novel compounds that inhibit novel pathways underscores the need for innovative drug discovery strategies. Here, we report a strategic advancement in PROSPECT (PRimary screening Of Strains to Prioritize Expanded Chemistry and Targets), which is an antimicrobial discovery strategy that measures chemical-genetic interactions between small molecules and a pool of bacterial mutants, each depleted of a different essential protein target, to identify whole-cell active compounds with high sensitivity. Applying this modified strategy to M. abscessus , in contrast to previously described versions of PROSPECT which utilized protein degradation or promoter replacement strategies for generating engineered hypomorphic strains, here we leveraged CRISPR interference (CRISPRi) to more efficiently generate mutants each depleted of a different essential gene involved in cell wall synthesis or located at the bacterial surface. We applied this platform to perform a pooled PROSPECT pilot screen of a library of 809 compounds using CRISPRi guides as mutant barcodes. We identified a range of active hits, including compounds targeting InhA, a well-known mycobacterial target but under-explored in the M. abscessus space. The unexpected susceptibility to isoniazid, traditionally considered to be ineffective in M. abscessus , suggested a complex interplay of several intrinsic resistance mechanisms. While further complementary efforts will be needed to change the landscape of therapeutic options for M. abscessus , we propose that PROSPECT with CRISPRi engineering provides an increasingly accessible, high-throughput target-based phenotypic screening platform and thus represents an important step towards accelerating early-stage drug discovery.
    Date: 2025-03-17
    Authors: Neo DM, Ben-Zion I, Bagnall J, Solomon M, Bond A, Gath E, Zhang S, Shoresh N, Gomez J, Hung DT.
    Ref: bioRxiv
  18. ABSTRACT Considerable offseason farmland lays fallow because there are few crops that can profitably fit between primary crops. To remedy, we employed CRISPR genome editing to the freeze-tolerant, rapid cycling wild Brassica, Thlaspi arvense L. (field pennycress). High-yielding domesticated pennycress varieties were created having seed compositions comparable to “double low” canola (low erucic acid and glucosinolate). Seed glucosinolate content was reduced 75 % by combining mutations in R2R3-MYB (MYB28) and bHLH MYC (MYC3) transcription factors. Pennycress weediness was greatly reduced by knockout of the bHLH transcription factor TRANSPARENT TESTA8 ( TT8 ), lowering seed dormancy and seed coat protections thereby mitigating pennycress re-emergence in fields. Domesticated pennycress offers farmers a profitable, low-carbon-intensity intermediate crop that confers ecosystem benefits while producing grain for renewable fuels and enhanced food security.
    Date: 2025-03-17
    Authors: Gautam B, Jarvis BA, Esfahanian M, McGinn M, Williams D, Liu S, Phippen ME, Heller NJ, Wesley TL, Phippen WB, Ulmasov T, Marks MD, Chopra R, Sedbrook JC.
    Ref: bioRxiv
  19. ABSTRACT Triple-negative breast cancer (TNBC) is an aggressive subtype with poor prognosis and limited treatments. Although 40-70% of TNBC cases overexpress EGFR, anti-EGFR therapies show minimal clinical benefit. This may result from inherent resistance, inactive EGFR, or its absence on the plasma membrane. Here, we used genome wide CRISPR knock out library screening to identify factors that mediate resistance to EGFR inhibitor. We discovered that depletion of a redox protein, thioredoxin reductase 3 (TXNRD3), in MDA-MB-231 cells reduces cell survival after Erlotinib treatment suggesting that loss of TXNRD3 may sensitize TNBC cells to EGFR inhibitors. siRNA-induced knockdown or pharmacological inhibition of TXNRD3 using an FDA-approved drug Auranofin significantly sensitized EGFR-high TNBC cells to EGFR inhibitors. Mechanistically, TXNRD3 knockdown or inhibition using Auranofin increased oxidative stress-mediated accumulation of phosphorylated EGFR at Y1068 and increased surface accumulation. Interestingly, combination of Auranofin with EGFR inhibition markedly induced antibody-dependent cell mediated cytotoxicity (ADCC) and exerted a significant anti-cancer activity in vivo model. Overall, our findings indicate that targeting TXNRD3 with Auranofin can activate EGFR and enhance its surface localization, thereby sensitizing TNBC cells to anti-EGFR therapies. This approach offers a promising strategy for treating TNBC patients who are resistant to current EGFR-targeted treatments.
    Date: 2025-03-17
    Authors: Raninga PV, Giner G, Sankarasubramanian S, Ambalathingal G, Kalimutho M, Herold MJ, Khanna KK.
    Ref: bioRxiv
  20. Clownfish exhibit striking color patterns, characterized primarily by the presence of zero to three vertical white bars, along with three main colors: orange, white, and black. The common ancestor of clownfish likely possessed three vertical bars, with several instances of gains and losses occurring throughout clownfish evolutionary history over the past 10 million years. However, the evolutionary genomic mechanisms underlying the gain or loss of vertical bars remain unknown. In this study, we tested whether vertical bar transitions across the clownfish phylogeny were associated with changes in non-synonymous to synonymous substitution rates ( d N /d S values). Our analyses identified pigmentation-related genes that underwent changes in selective pressure, including gch2, oca2 , and vps11 , which are linked to melanophores, iridophores, and visual function. Additionally, pmel , a key melanogenesis gene, was found under positive selection, suggesting its role in shaping bar patterning. These results provide new insights into the genomic basis of coloration in clownfish, highlighting how selection and genetic variation influence phenotypic evolution.
    Date: 2025-03-17
    Authors: Fitzgerald LM, Latrille T, Marcionetti A, Gaboriau T, Hartasánchez DA, Salamin N.
    Ref: bioRxiv
  21. Small G protein ARL13B localizes to the cilium and plays essential roles in cilium biogenesis, organization, trafficking, and signaling. Here, we established multiple ARL13B knockout cell lines using the CRISPR/Cas9 system. Surprisingly, all our cell lines lost their cilia completely, in contrast to the reported short cilium and reduced ciliogenesis phenotype. We found that multiple regions of ARL13B are necessary for a complete rescue. Additionally, we found that ARL13B knockout cells also lost their response to sonic hedgehog stimulation. Our work demonstrates the absolute requirement of ARL13B for ciliogenesis and sonic hedgehog signaling, at least in cultured cells, and suggest that ARL13B plays a far more critical role in ciliary function than previously understood.
    Date: 2025-03-17
    Authors: Mahajan D, Chia HM, Lu L.
    Ref: bioRxiv
  22. ABSTRACT The mechanical properties of cells are dynamic, allowing them to adjust to different needs in different biological contexts. In recent years, advanced biophysical techniques have enabled the rapid, high-throughput assessment of single-cell mechanics, providing new insights into the regulation of the mechanical cell phenotype. However, the molecular mechanisms by which cells maintain and regulate their mechanical properties remain poorly understood. Here, we present a genome-scale RNA interference (RNAi) screen investigating the roles of kinase and phosphatase genes in regulating single-cell mechanics using Real-Time Fluorescence and Deformability Cytometry (RT-FDC). Our screen identified 82 known and novel mechanical regulators across diverse cellular functions from 214 targeted genes, leveraging RT-FDC’s unique capabilities for comprehensive, high-throughput mechanical phenotyping with single-cell and cell cycle resolution. These findings refine our understanding of how signaling pathways coordinate structural determinants of cell mechanical phenotypes and provide a starting point for uncovering new molecular targets involved in biomechanical regulation across diverse biological systems. SIGNIFICANCE Cell mechanical properties are tightly regulated and play pivotal roles in processes ranging from tissue morphogenesis to disease progression. Despite their importance, the genetic regulation of single-cell mechanics remains largely unexplored. This study represents one of only a few large-scale mechanomic investigations conducted to date. It is the first study to leverage RT-FDC’s unique capability for high-throughput mechanical phenotyping with single-cell and cell cycle resolution to detect gene impacts that may be overlooked in lower-throughput or population-level studies. The mechanical genes identified here provide valuable data points for understanding how cells control their mechanical state and serve as a foundation for future studies exploring the molecular basis of biomechanical regulation.
    Date: 2025-03-17
    Authors: Strampe L, Plak K, Schweitzer C, Liebers C, Müller P, Baum B, Kayser J, Guck J.
    Ref: bioRxiv
  23. The dark proteome includes a rapidly expanding catalog of microproteins with unknown functions that have been historically ignored in genome annotations. Here, we exploit an in vivo single-cell CRISPR screening strategy in the mouse epidermis to systematically investigate the tissue-wide function of microproteins. We document the global and cell-type-specific roles of microproteins during epidermal development and homeostasis at single-cell transcriptomic resolution. Focusing on select candidates, we identify a novel microprotein on Gm10076 , identical to the ribosomal intersubunit bridge protein RPL41, whose perturbation strongly impairs proliferation and protein synthesis. Employing ribosome profiling and RNA sequencing, we show that Gm10076 perturbation profoundly reshapes the translational landscape. Contrary to its prior classification as nonessential, we find that the ribosomal protein RPL41 is essential for cellular proliferation, warranting further investigation into its role as an intersubunit bridge in the translational machinery. Together, our study comprehensively charts the tissue-wide functional landscape of the dark proteome, uncovers a second Rpl41 gene critical for ribosome function and establishes a basis for exploring the impact of microproteins on disease pathogenesis.
    Date: 2025-03-17
    Authors: Valdivia-Francia F, Ghoshdastider U, Renz PF, Spies D, Ormiston M, Hyams K, Shi C, Duré C, Yigit M, Taborsky D, Khandekar A, Weber R, Yamahachi H, Ellis SJ, Sendoel A.
    Ref: bioRxiv
  24. Obesity is a major public health crisis, affecting billions worldwide and increasing the risk of metabolic and cardiovascular diseases. While lifestyle factors play a role, genetic variation is a key determinant of both obesity susceptibility and the efficacy of treatment strategies. Recent studies have implicated the Semaphorin 3 signalling pathway in obesity; however, specific roles for pathway components remain largely unexplored. Here, we focus on Class A Plexins and their potential contributions to body weight regulation. Using large-scale genetic association data, we identified that rare, predicted loss-of-function mutations in PLXNA4 were associated with body mass index (BMI) in females. Furthermore, common variant analysis revealed that genetic variation at PLXNA4 was linked to BMI, height, and various neuropsychiatric disorders. To investigate the biological role of Plxna4, we generated zebrafish plxna4 loss-of-function mutants, which exhibited an 85–92% reduction in Plxna4 protein. Despite appearing morphologically normal, mutant zebrafish at juvenile stages were shorter, had increased body fat levels relative to size-matched wild-type siblings, and displayed hypertrophic subcutaneous adipose tissue. Feeding assays revealed that plxna4 mutants consumed more food than wild-type siblings and exhibited food-stimulated hyperactivity, characterised by increased swimming speed, higher speed variability, and frequent high-speed bursts. Together, these findings demonstrate a conserved role for Plxna4 in regulating feeding behaviour and body fat levels, providing new insights into the genetic basis of obesity and warranting further studies to elucidate the molecular mechanisms underlying these effects.
    Date: 2025-03-16
    Authors: Tandon P, Lyall Z, Cowie M, Minchin JEN.
    Ref: bioRxiv
  25. Genetic engineering is a formidable approach to study biology. The development of CRISPR-Cas9 has allowed the genetic engineering of insect species from several orders, and in some species, this tool is used routinely for genetic research. However, insect gene editing often relies on the delivery of CRISPR-Cas9 components via embryo injection. This technique has a limitation: some species lay their eggs inside hard substrates or living hosts, making embryo collection impossible or labour-intensive. Recently, a variety of techniques that exploit maternal injection of nucleases have been developed to circumvent embryo injection. Yet, despite this variety of maternal delivery techniques, some insects remain refractory to gene editing. One of these is the parasitoid wasp, Nasonia vitripennis , an important hymenopteran model species. In this study, a recently developed method termed SYNCAS was used to perform knock-out (KO) of the cinnabar gene in this wasp, obtaining KO efficiencies up to ten times higher than reported for other maternal injection approaches. We found up to 2.73% of all offspring to display a KO phenotype, and we obtained up to 68 KO offspring per 100 injected mothers. The optimal timing of injection and provision of hosts for egg laying was determined. With this protocol, routine applications of CRISPR-Cas9 become feasible in this species, allowing reverse genetics studies of genes with unknown associated phenotypes and paving the way for more advanced editing techniques. Abstract Figure Maternal injection of Cas9 RNP together with BAPC and saponins (SYNCAS) results in efficient gene editing of Nasonia vitripennis offspring Timing of injection and egg collection is important for maximising efficiency and reducing screening effort The efficient genetic engineering of Nasonia vitripennis suggests the applicability of SYNCAS to other parasitoid wasps, a category of insects particularly difficult to genetically engineer with embryonic Cas9 injections.
    Date: 2025-03-16
    Authors: Guerra F, De Rouck S, Verhulst EC.
    Ref: bioRxiv
first · previous · 10 · 11 · 12 · 13 · 14 · 15 · 16 · 17 · 18 · 19 · next · last