bioRxiv Science⌕ Search

Biology subjects

Lin, B.

Publications and source records attributed to Lin, B..

At least 37 records · Page 2Linked to original sources

YAP1 drives aggressive and therapy resistant state in melanoma through reprogramming the chromatin and regulating immune evasive programs

Despite promising initial results in targeting the RAF-MEK-ERK cascade, resistance to BRAF/MEK inhibitors remains a critical challenge in nearly 50% of melanoma patients. Our study demonstrates that robust YAP1 activation in metastatic melanoma correlates with poor survival and drives transcriptional programs linked to therapeutic resistance. Mechanistically, YAP1 predominantly remodels the chromatin landscape in resistant tumors by partnering with BRD4 and TEAD, creating a permissive transcriptional state that sustains oncogenic signaling. Clinical validation in biopsies from resistant melanoma confirms elevated expression of YAP1 target genes. Furthermore, pharmacological inhibition of BRD4 or TEAD reduces YAP1-driven transcription and reactivates antitumor immunity programs. TEAD specific inhibitors (and not verteporfin which is a highly non-specific inhibitor) synergize with immune checkpoint blockade in in vivo model system by promoting increased CD8 T cell infiltration and prolonged survival in the melanoma mouse model. Collectively, these findings reveal a chromatin-centric vulnerability in BRAF/MEK inhibitor-resistant melanoma and propose TEAD specific inhibitors as a promising dual strategy to overcome resistance and reinvigorate the immune response, offering a novel therapeutic avenue for patients. Resistance to BRAF and MEK inhibitors remains a major obstacle in the treatment of melanoma. Here, we show that elevated YAP1 activity in metastatic melanoma is associated with poor patient survival and drives transcriptional programs that promote therapeutic resistance. Mechanistically, YAP1 cooperates with BRD4 and TEAD to reprogram the chromatin landscape, establishing an oncogenic transcriptional state that sustains resistance. Analysis of patient-derived melanoma biopsies confirms increased expression of YAP1 target genes in resistant tumors. Targeting this epigenetic circuitry using pharmacological inhibitors of BRD4 or TEAD effectively suppresses YAP1-driven transcriptional output and restores antitumor immune activity, as evidenced by enhanced CD8 T cell infiltration and prolonged survival in resistant melanoma models. These effects are further supported by transcriptomic and chromatin accessibility analyses, which reveal reduced expression of immune-suppressive and proliferation-associated gene networks upon TEAD inhibition. Collectively, our findings identify a chromatin-centric mechanism underlying resistance to MAPK-targeted therapy and nominate TEAD inhibition as a promising dual-action strategy to both overcome resistance and re-engage antitumor immunity. This work offers a compelling therapeutic avenue for patients with drug-resistant melanoma.

cancer biology↗

Adaptation of motor control strategies and physiological arousal during repeated blocks of split-belt walking

Physiological arousal, mediated by the autonomic nervous system (ANS), is known to co-modulate with adaptation of motor control strategies, governed by the central nervous system (CNS), in response to repeated standing perturbations. However, adaptation of the ANS physiological arousal response during repeat exposure to walking challenges remains unknown. This study examines the physiological arousal response (electrodermal activation, EDA) and motor control strategy of gait during a single session of repeated exposure to blocks of split-belt walking. Twenty young adults completed three repeated blocks (3.5 min each) of split-belt walking (2:1 speed ratio) alternating with three blocks of tied-belt walking. Step length symmetry (SLS), EDA, bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) muscle activation and ground reaction forces (GRFs) were measured. For each walking block, the first (early) and last (late) 15 strides were analyzed. A linear mixed-effects model (LMM) tested the effect of repeated blocks and phases (early/late) on SLS. Statistical parametric mapping (SPM) examined patterns of within-block changes in EDA, muscle activation, and GRFs. The greatest within-block adaptation of SLS occurred during first exposure to split-belt walking (S1; p<.001). Similarly, the largest magnitude of within-block adaptation in muscle activation, GRFs, and EDA occurred during S1 (p<.05). Attenuated EDA responses together with lower magnitude of motor adaptation in subsequent split blocks 2 and 3 were observed, indicating savings across the ANS and CNS. Taken together, these findings demonstrate that the ANS-mediated physiological arousal response modulates alongside the CNS-driven locomotor adaptation to repeated exposure to blocks of split-belt walking.

neuroscience↗

Surface proteomics reveals arginine metabolism as a vulnerability in high grade serous ovarian cancer

The significant lethality of high-grade serous ovarian cancer (HGSC) is driven by the lack of long-term efficacy of current treatments, underscoring the need for developing additional therapeutics. Cell surface proteins represent attractive therapeutic targets yet remain underexplored in high-grade serous ovarian cancer. Here, we employed cell surface N-glycoproteomics to elucidate the cell surface proteomes of HGSC cells alongside normal epithelial and cancer-associated stromal cells, uncovering new opportunities for therapeutic intervention. Integration of cell surface N-glycoproteomics and functional screening revealed multiple minimally characterized, HGSC-enriched surface proteins that are critical for HGSC proliferation, most notably, SLC7A1. Multi-omic and functional characterization indicated that SLC7A1 is necessary for HGSC migration, protein synthesis and mitochondrial functions likely linked to its role as an arginine transporter. Finally, we demonstrate that elevated surface expression of SLC7A1 in HGSC reflects dysregulated arginine metabolism, pointing to a putative therapeutic vulnerability. Our work identifies SLC7A1 and arginine metabolism as a previously unrecognized molecular vulnerability in HGSC and provides a framework to guide future therapeutic development.

cancer biology↗

Suppression of interferon signaling via small molecule modulation of TFAM

The mitochondrial transcription factor A (TFAM) is essential for mitochondrial genome maintenance. It binds to mitochondrial DNA (mtDNA) and determines the abundance, packaging and stability of the mitochondrial genome. Because its function is tightly associated with mtDNA, TFAM has a protective role in mitochondrial diseases and supportive studies demonstrate reversal of disease phenotypes by TFAM overexpression. In addition, TFAM deficiency has been shown to cause release of mtDNA into the cytosol and activation of the cGAS/STING innate immune response pathway. As such, TFAM presents as a unique target for therapeutic intervention, but limited efforts for activators have been reported. Herein we disclose novel TFAM small molecule modulators with sub-micromolar activity. Our results demonstrate that these compounds result in increase of TFAM protein levels and mtDNA copy number. This results in inhibition of a mtDNA stress-mediated inflammatory response by preventing mtDNA escape into the cytosol. Furthermore, we see beneficial effects in cellular disease models in which boosting TFAM activity has been advanced as a disease modifying strategy including improved energetics in MELAS cybrid cells and a decrease of fibrotic markers in Systemic Sclerosis (SSc) fibroblasts. These results highlight the therapeutic potential of using small molecule TFAM activators in indications characterized by mitochondrial dysfunction.

cell biology↗

Reduced efficacy of an anti-toxin vaccine from senescence-driven attenuation of toxin virulence

It remains unclear why vaccines targeting prominent microbial virulence factors often fail in clinical trials. Because microbial virulence depends on interaction with the host immune system, we investigated how changes in host immune function alter vaccine efficacy. Using a vaccine against Staphylococcus aureus alpha toxin (Hla), which targets host metalloprotease ADAM10 on myeloid cells, we show that Hla virulence is reduced in aged mice due to diminished ADAM10 activity and impaired myeloid cell function. Depletion of myeloid cells with cyclophosphamide in young mice similarly reduced toxin virulence. Immunization against Hla conferred strong protection against Staphylococcus aureus infection in young but not aged mice. These findings indicate that pathogenic functions of microbial factors characterized in immunocompetent young animals may not predict virulence or vaccine efficacy in immunocompromised hosts. These findings underscore the need to account for host immune status in the development and evaluation of vaccines targeting microbial virulence factors.

microbiology↗

Rapid, Efficient Candida albicans Lysis Comparison Using the Cellometer X2 Fluorescent Cell Viability Counter

Cell lysis is essential for extracting intake genetic material, forming the basis for diagnostic tests, and genetic studies. Commonly used lysis methods include thermal lysis, mechanical force, chemicals, biologicals, and sonication. Determining effective lysis methods for specific cell types is crucial for conducting further research. This study evaluates the lysis efficiency of Candida albicans using the Cellometer X2 fluorescent cell viability counter, employing various lysis methods: thermal, chemical, and enzymatic. Our results indicate that high-pH buffers combined with heat treatment enhance lysis efficiency, while SDS alone or with Proteinase K is insufficient for lysis at room temperature. In contrast, Zymolyase effectively lyses C. albicans at room temperature in 150 minutes, making the automation of room temperature lysis and nucleic acid purification feasible for C. albicans. Overall, this study highlights the Cellometer X2s capability for rapid and direct evaluation of cell lysis efficiency.

microbiology↗

A Python Toolbox for Representational Similarity Analysis

Representational similarity analysis (RSA) is a method to characterize neural representations and evaluate computational models based on neural representational geometries. Here we present a wave of recent methodological advances, including improved measures of representational distances, evaluators for representational models, and statistical inference methods, which are available to the community in a new open-source toolbox in Python. The rsatoolbox enables neuroscientists to explore neural representational geometries and to evaluate neural network models, connecting theory to experiment in the new era of big models and big data.

neuroscience↗

Shared Transcriptomic Signatures Reveal Synaptic Pruning as a Link Between Alzheimer's Disease and Epilepsy

Alzheimers disease (AD) and epilepsy (EP) share a complex bidirectional relationship, yet the molecular mechanisms underlying their comorbidity remain insufficiently explored. To identify potential transcriptional programs across animal models and human patients with AD and EP, we conducted a comprehensive genome-wide transcriptomic analysis. Our investigation included mouse models of temporal lobe epilepsy (pilocarpine- and kainic acid-induced; n = 280), AD transgenic models (7 transgenic models expressing human tau or amyloid pathology; n = 257), and performed cross-species validation in human cohorts (EP: n = 182; AD: n = 301). We identified a highly conserved immune-related module across all models and patient cohorts. The hub consensus signatures of this module were centered around a microglial synaptic pruning pathway involving TYROBP, TREM2, and C1Q complement components. Gene regulatory network analysis identified TYROBP as the key upstream hub signature. These signatures showed consistent up-regulation in both conditions and strong diagnostic potential. Differential expression analyses revealed their predominant expression in specific microglial subpopulations associated with complement-mediated synaptic pruning and immune activation. Neural circuit modeling further demonstrates the asymmetric sensitivity of synaptic pruning to network dynamics. Loss of inhibitory synapses has a disproportionately significant impact on neural network excitation/inhibition balance and synchronization. Our findings support microglial complement-mediated synaptic pruning as a conserved central pathway linking neurodegeneration to epileptogenesis, suggesting a promising therapeutic target for AD and EP comorbidity. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=193 SRC="FIGDIR/small/618752v12_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@179aa28org.highwire.dtl.DTLVardef@922dfaorg.highwire.dtl.DTLVardef@108a99eorg.highwire.dtl.DTLVardef@1b7d2f6_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIGenome-wide transcriptomic analysis across epilepsy (EP) and Alzheimers disease (AD) models and patients identified a conserved immune module. C_LIO_LIThe TYROBP-TREM2-C1Q microglial synaptic pruning pathway was identified as a central consensus signature across model and patient cohorts. C_LIO_LIConsensus signatures possess potential diagnostic utility in AD and EP patients, with predominant expression in specific microglial subpopulations C_LIO_LINeural circuit modeling demonstrates the asymmetric effects of synaptic pruning, whereby loss of inhibitory synapses disproportionately disrupts the E/I balance, leading to increased network synchronization. C_LI

bioinformatics↗

Spatial Immunophenotyping from Whole-Slide Multiplexed Tissue Imaging Using Convolutional Neural Networks

The multiplexed immunofluorescence (mIF) platform enables biomarker discovery through the simultaneous detection of multiple markers on a single tissue slide, offering detailed insights into intratumor heterogeneity and the tumor-immune microenvironment at spatially resolved single cell resolution. However, current mIF image analyses are labor-intensive, requiring specialized pathology expertise which limits their scalability and clinical application. To address this challenge, we developed CellGate, a deep-learning (DL) computational pipeline that provides streamlined, end-to-end whole-slide mIF image analysis including nuclei detection, cell segmentation, cell classification, and combined immuno-phenotyping across stacked images. The model was trained on over 750,000 single cell images from 34 melanomas in a retrospective cohort of patients using whole tissue sections stained for CD3, CD8, CD68, CK-SOX10, PD-1, PD-L1, and FOXP3 with manual gating and extensive pathology review. When tested on new whole mIF slides, the model demonstrated high precision-recall AUC. Further validation on whole-slide mIF images of 9 primary melanomas from an independent cohort confirmed that CellGate can reproduce expert pathology analysis with high accuracy. We show that spatial immuno-phenotyping results using CellGate provide deep insights into the immune cell topography and differences in T cell functional states and interactions with tumor cells in patients with distinct histopathology and clinical characteristics. This pipeline offers a fully automated and parallelizable computing process with substantially improved consistency for cell type classification across images, potentially enabling high throughput whole-slide mIF tissue image analysis for large-scale clinical and research applications.

bioinformatics↗

RIPK4 driven by TP53 mutations promotes resistance to redox stress of CRC by phosphorylating MTHFD1

This study investigates advanced colorectal cancer (CRC), focusing on its tendency for distant metastasis and chemotherapy resistance. It highlights the importance of PANoptosis, a cell death pathway, and the role of the Receptor-interacting serine/threonine-protein kinase (RIPK) family in tumor progression. RIPK4s tissue-specific functions in cancer cell behavior are emphasized, including its influence on invasion, migration, and oxidative stress resistance. The study reveals the critical balance of reactive oxygen species (ROS) in cancer cells, linked to antioxidant defenses and NADPH production for survival. A key finding is the connection between TP53 mutations in CRC and increased RIPK4 expression, which enhances MTHFD1 phosphorylation, boosts NADPH production, reduces ROS, and promotes resistance to PANoptosis, leading to metastasis. The research identifies the molecular basis of CRC metastasis, showing how RIPK4 regulates MTHFD1 to resist PANoptosis, offering new therapeutic targets for metastatic CRC and potential improvements in patient outcomes.

molecular biology↗

FLASH radiotherapy using high-energy X-rays: validation of the FLASH effect triggered by a compact single high-energy X-ray source device

PurposeThis preclinical study aimed to verify the FLASH effect of compact single high-energy X-ray source (CHEXs) and to explore whether three irradiations with single-gantry rotation two 30 s pauses can generate FLASH effect in mice. Materials and methodsThe absolute dose and pulsed beam of the CHEXs were measured using an EBTXD radiochromic film and fast current transformer. Healthy C57BL/6J female mice and a subcutaneous tumor model were irradiated under different conditions: sham (control), FLASH-RT (FLASH1: delivering the total dose in 1 fraction; FLASH3: delivering the total dose with two 30 second pauses to simulate a three-field delivery where the gantry rotation is occurring within 30 seconds), and conventional dose rate radiotherapy (CONV-RT). Various total doses were administered to the corresponding normal tissues (whole thorax, 30 Gy; whole abdomen, 12 Gy; and skin, 36 Gy) and tumors (CT26, 16.5 Gy; and LLC, 18 Gy). Survival status, normal tissue damage, and tumor growth suppression were recorded in each group. ResultsThe average dose rate of the CHEXs exceeded 40 Gy/s. For whole-thorax and skin irradiation, both FLASH1 and FLASH3 demonstrated protective effects. For whole-abdomen irradiation, FLASH1 exhibited a superior protective effect. No significant differences in tumor growth responses were observed between the FLASH1, FLASH3, and CONV-RT groups (P>0.05). ConclusionThis study confirmed that the FLASH effect could be triggered using CHEXs FLASH radiotherapy, and demonstrated that three irradiations with single gantry rotation two 30 s pauses can trigger the FLASH effect, indicating the potential benefit of CHEXs 3D conformal radiotherapy. Our findings indicate that further clinical trials on CHEXs are warranted.

cancer biology↗

A Cost-effective, High-throughput, Highly Accurate Genotyping Method for Outbred Populations

Affordable sequencing and genotyping methods are essential for large scale genome-wide association studies. While genotyping microarrays and reference panels for imputation are available for human subjects, non-human model systems often lack such options. Our lab previously demonstrated an efficient and cost-effective method to genotype heterogeneous stock rats using double-digest genotyping-by-sequencing. However, low-coverage whole-genome sequencing offers an alternative method that has several advantages. Here, we describe a cost-effective, high-throughput, high-accuracy genotyping method for N/NIH heterogeneous stock rats that can use a combination of sequencing data previously generated by double-digest genotyping-by-sequencing and more recently generated by low-coverage whole-genome-sequencing data. Using double-digest genotyping-by-sequencing data from 5,745 heterogeneous stock rats (mean 0.21x coverage) and low-coverage whole-genome-sequencing data from 8,760 heterogeneous stock rats (mean 0.27x coverage), we can impute 7.32 million bi-allelic single-nucleotide polymorphisms with a concordance rate >99.76% compared to high-coverage (mean 33.26x coverage) whole-genome sequencing data for a subset of the same individuals. Our results demonstrate the feasibility of using sequencing data from double-digest genotyping-by-sequencing or low-coverage whole-genome-sequencing for accurate genotyping, and demonstrate techniques that may also be useful for other genetic studies in non-human subjects. Article SummaryHeterogeneous stock rats were derived by interbreeding eight inbred founders in 1984, and have been maintained as an outbred population for more than 100 generations. Heterogeneous stock rats offer a high degree of genetic and phenotypic diversity, and have been extensively used for genetic studies. Here, we describe a cost-effective and high-throughput genotyping method for heterogeneous stock rats. We applied the method to 15,552 heterogeneous stock rats. The resulting genotypes were highly accurate. These techniques may be useful for genetic studies in other non-human subjects.

genetics↗

Airway basal stem cells are necessary for the maintenance of functional intraepithelial airway macrophages.

Adult stem cells play a crucial role in tissue homeostasis and repair through multiple mechanisms. In addition to being able to replace aged or damaged cells, stem cells provide signals that contribute to the maintenance and function of neighboring cells. In the lung, airway basal stem cells also produce cytokines and chemokines in response to inhaled irritants, allergens, and pathogens, which affect specific immune cell populations and shape the nature of the immune response. However, direct cell-to-cell signaling through contact between airway basal stem cells and immune cells has not been demonstrated. Recently, a unique population of intraepithelial airway macrophages (IAMs) has been identified in the murine trachea. Here, we demonstrate that IAMs require Notch signaling from airway basal stem cells for maintenance of their differentiated state and function. Furthermore, we demonstrate that Notch signaling between airway basal stem cells and IAMs is required for antigen-induced allergic inflammation only in the trachea where the basal stem cells are located whereas allergic responses in distal lung tissues are preserved consistent with a local circuit linking stem cells to proximate immune cells. Finally, we demonstrate that IAM-like cells are present in human conducting airways and that these cells display Notch activation, mirroring their murine counterparts. Since diverse lung stem cells have recently been identified and localized to specific anatomic niches along the proximodistal axis of the respiratory tree, we hypothesize that the direct functional coupling of local stem cell-mediated regeneration and immune responses permits a compartmentalized inflammatory response.

cell biology↗

ATP Citrate Lyase Supports Cardiac Function and NAD+/NADH Balance And Is Depressed in Human Heart Failure

BackgroundATP-citrate lyase (ACLY) converts citrate into acetyl-CoA and oxaloacetate in the cytosol. It plays a prominent role in lipogenesis and fat accumulation coupled to excess glucose, and its inhibition is approved for treating hyperlipidemia. In RNAseq analysis of human failing myocardium, we found ACLY gene expression is reduced; however the impact this might have on cardiac function and/or metabolism has not been previously studied. As new ACLY inhibitors are in development for cancer and other disorders, such understanding has added importance. MethodsCardiomyocytes, ex-vivo beating hearts, and in vivo hearts with ACLY inhibited by selective pharmacologic (BMS303141, ACLYi) or genetic suppression, were studied. Regulation of ACLY gene/protein expression, and effects of ACLYi on function, cytotoxicity, tricarboxylic acid (TCA)-cycle metabolism, and redox and NAD+/NADH balance were assessed. Mice with cardiac ACLY knockdown induced by AAV9-acly-shRNA or cardiomyocyte tamoxifen-inducible Acly knockdown were studied. ResultsAcly gene expression was reduced more in obese patients with heart failure and preserved EF (HFpEF) than HF with reduced EF. In vivo pressure-overload and in vitro hormonal stress increased ACLY protein expression, whereas it declined upon fatty-acid exposure. Acute ACLYi (1-hr) dose-dependently induced cytotoxicity in adult and neonatal cardiomyocytes, and caused substantial reduction of systolic and diastolic function in myocytes and ex-vivo beating hearts. In the latter, ATP/ADP ratio also fell and lactate increased. U13C-glucose tracing revealed an ACLY-dependent TCA-bypass circuit in myocytes, where citrate generated in mitochondria is transported to the cytosol, metabolized by ACLY and then converted to malate to re-enter mitochondria, bypassing several NADH-generating steps. ACLYi lowered NAD+/NADH ratio and restoring this balance ameliorated cardiomyocyte toxicity. Oxidative stress was undetected with ACLYi. Adult hearts following 8-weeks of reduced cardiac and/or cardiomyocyte ACLY downregulation exhibited ventricular dilation and reduced function that was prevented by NAD augmentation. Cardiac dysfunction from ACLY knockdown was worse in hearts subjected to sustained pressure-overload, supporting a role in stress responses. ConclusionsACLY supports normal cardiac function through maintenance of the NAD+/NADH balance and is upregulated by hemodynamic and hormonal stress, but depressed by lipid excess. ACLY levels are most reduced in human HFpEF with obesity potentially worsening cardio-metabolic reserve.

molecular biology↗

An organoid co-culture model for probing systemic anti-tumor immunity in lung cancer

Deciphering the interactions between tumor micro- and systemic immune macro-environment is essential for developing more effective cancer diagnosis and treatment strategies. Here, we established a gel-liquid interface (GLI) co-culture of lung cancer organoids (LCOs) and paired peripheral blood mononuclear cells (PBMCs), featuring with enhanced interactions of immune cells and tumor organoids, to mimic the in vivo systemic anti-tumor immunity induced by immune checkpoint inhibitors (ICI). The co-culture model recapitulates the in vivo ICI-induced T cell recruitment and subsequent tumor regression, predicting the clinical results precisely. We demonstrated that circulating tumor-reactive T cells, which are effector memory-like with high expression levels of GNLY, CD44 and CD9, can serve as an indicator of the immunotherapy efficacy. Interestingly, enhanced inflammatory signaling in blood T cells is accompanied with prompted exhaustion and compromised anti-tumor function, when encountering with organoids. Our findings suggest that the GLI co-culture can be used for developing diagnostic strategies for precision immunotherapies as well as understanding the underlying mechanisms. Summary figure O_FIG O_LINKSMALLFIG WIDTH=178 HEIGHT=200 SRC="FIGDIR/small/597327v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@a0829dorg.highwire.dtl.DTLVardef@1df3083org.highwire.dtl.DTLVardef@1ea1065org.highwire.dtl.DTLVardef@1da9464_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Transformation of an olfactory placode-derived cell into one with stem cell characteristics by disrupting epigenetic barriers

The mammalian olfactory neuronal lineage is regenerative, and accordingly, maintains a population of pluripotent cells that replenish olfactory sensory neurons and other olfactory cell types during the life of the animal. Moreover, in response to acute injury, the early transit amplifying cells along the olfactory sensory neuronal lineage are able to de-differentiate to shift resources in support of tissue restoration. In order to further explore plasticity of various cellular stages along the olfactory sensory neuronal lineage, we challenged the epigenetic stability of two olfactory placode-derived cell lines that model immature olfactory sensory neuronal stages. We found that perturbation of the Ehmt2 chromatin modifier transformed the growth properties, morphology, and gene expression profiles towards states with several stem cell characteristics. This transformation was dependent on continued expression of the large T-antigen, and was enhanced by Sox2 over-expression. These findings may provide momentum for exploring inherent cellular plasticity within early cell types of the olfactory lineage, as well as potentially add to our knowledge of cellular reprogramming. SUMMARY STATEMENTDiscovering how epigenetic modifications influence olfactory neuronal lineage plasticity offers insights into regenerative potential and cellular reprogramming.

molecular biology↗

Identification and classification of the genomes of novel Microviruses in a poultry slaughterhouse

Microviridae is a family of phages with circular ssDNA genomes and they are widely found in various environments and organisms. In this study, Virome techniques were employed to explore potential members of Microviridae in poultry slaughterhouse, leading to the identification of 98 novel and complete microvirus genomes. Using a similarity clustering network classification approach, these viruses were found to belong to at least 6 new subfamilies within Microviridae and 3 higher-level taxonomic units. Analysis of their genomes found that the genome size, GC content and genome structure of these new taxa showed evident regularities, validating the rationality of our classification method. Compared with the 19 families classified by previous researchers for microviruses dataset, our method can divide microviruses into about 45 more detailed clusters, which may serve as a new standard for classifying Microviridae members. Furthermore, addressing the scarcity of host information for microviruses, this study significantly broadened their host range and discovered over 20 possible new hosts, including important pathogenic bacteria such as Helicobacter pylori and Vibrio cholerae, as well as different taxa demonstrated differential host specificity. The findings of this study effectively expand the diversity of the Microviridae, providing new insights for their classification and identification. Additionally, it offers a novel perspective for monitoring and controlling pathogenic microorganisms in poultry slaughterhouse environments.

microbiology↗

Genome-wide association study of delay discounting in Heterogenous Stock rats

Delay discounting refers to the behavioral tendency to devalue rewards as a function of their delay in receipt. Heightened delay discounting has been associated with substance use disorders, as well as multiple co-occurring psychopathologies. Genetic studies in humans and animal models have established that delay discounting is a heritable trait, but only a few specific genes have been associated with delay discounting. Here, we aimed to identify novel genetic loci associated with delay discounting through a genome-wide association study (GWAS) using Heterogenous Stock rats, a genetically diverse outbred population derived from eight inbred founder strains. We assessed delay discounting in 650 male and female rats using an adjusting amount procedure in which rats chose between smaller immediate sucrose rewards or a larger reward at variable delays. Preference switch points were calculated for each rat and both exponential and hyperbolic functions were fitted to these indifference points. Area under the curve (AUC) and the discounting parameter k of both functions were used as delay discounting measures. GWAS for AUC, exponential k, and indifference points for a short delay identified significant loci on chromosomes 20 and 14. The gene Slc35f1, which encodes a member of the solute carrier family of nucleoside sugar transporters, was the only gene within the chromosome 20 locus. That locus also contained an eQTL for Slc35f1, suggesting that heritable differences in the expression of that gene might be responsible for the association with behavior. The gene Adgrl3, which encodes a member of the latrophilin family of G-protein coupled receptors, was the only gene within the chromosome 14 locus. These findings implicate novel genes in delay discounting and highlight the need for further exploration.

genomics↗