Biology subjects

Xu, W.

Publications and source records attributed to Xu, W..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

Metabolic adaptation to maternal hyperglycemia via ACLY-dependent acetyl-CoA production drives epigenetic remodeling and dysregulated placental development

AbstractsGestational diabetes mellitus (GDM) is a common metabolic complication of pregnancy that is paradoxically associated with both fetal overgrowth and fetal growth restriction (FGR). While maternal hyperglycemia is widely presumed to drive macrosomia through excessive nutrient supply, the mechanisms underlying FGR remain poorly understood. Here, using a mouse model that recapitulates the small-for-gestational-age (SGA) phenotype observed in human GDM pregnancies, we identify placental underdevelopment as a principal driver of FGR. Despite systemic nutrient abundance, hyperglycemic placentas exhibit reduced mass and an increased fetal-to-placental weight ratio, indicative of placental insufficiency. Mechanistically, maternal hyperglycemia induces anabolic metabolic rewiring while suppressing oxidative phosphorylation (OXPHOS), accompanied by upregulation and nuclear redistribution of ATP-citrate lyase (ACLY). ACLY converts glucose-derived carbon into acetyl-CoA in the cytosol and nucleus, thereby coupling glycolytic flux to lipid and hexosamine biosynthesis as well as to global histone hyperacetylation. This hyperacetylation-associated epigenetic reprogramming activates metabolic, innate immune, and inflammatory gene programs while repressing pro-proliferative and anti-apoptotic pathways. Consequently, placental growth is compromised despite nutrient excess. Importantly, activation of the ACLY-acetyl-CoA axis and global histone hyperacetylation is consistently observed in human GDM placentas across diverse birth outcomes, suggesting a conserved metabolic-epigenetic adaptation to maternal hyperglycemia. Together, these findings identify ACLY-dependent acetyl-CoA production as a central metabolic node linking maternal hyperglycemia to chromatin remodeling and placental development control, thereby reshaping fetal growth trajectories.

developmental biology↗

bioRxiv2026

Reconstituting Mouse Embryogenesis Ex Utero from Gastrulation to Fetal Development Reveals Maternally Independent Metabolic Programs

Mammalian development takes place inside the maternal uterus, creating technological constraints that make difficult the study of embryogenesis in live developing embryos. A central challenge for understanding the role of metabolism in mammalian development is discriminating placental and uterine-regulated signals from embryo-intrinsic processes independent of maternal influence, a process that until now has remained inseparable during gastrulation and organogenesis1-3. Ex utero culture systems allowing continuous growth of embryos during pre-gastrulation to organogenesis4,5 offer a promising solution to this challenge. Here, we present optimized ex utero culture platforms that support faithful development of mouse embryos from gastrulation (embryonic day 6.5/7.5) through the fetal period (embryonic day [~]12.5) and harnessed these platforms for dissecting metabolic transitions in vivo during embryogenesis independently of uterus and placenta. We characterized the metabolome of in utero and ex utero whole embryos, fetal organs and culture medium between embryonic days E6.5 and E12.5 by liquid chromatography mass-spectrometry (LC-MS) metabolomics, isotope tracing, and single cell transcriptomics. These datasets present a comprehensive overview of the dynamic embryonic metabolism during gastrulation and organogenesis in utero and ex utero. This analysis revealed that the midgestational metabolic switch occurring at E10.5-E11.5 is faithfully recapitulated ex utero, indicating that this transition is intrinsically programmed in embryonic tissues and does not require direct maternal or placental cues. Notably, oxygen availability modulated the extent of this transition, but elevated oxygen was insufficient to induce it prematurely, demonstrating that the switch is developmentally timed and only partially environmental-responsive. We further harnessed the ex utero platform for identifying and perturbing a mitochondrial redox shift at E7.5-E8.5 that is critical for developmental progress after gastrulation. These findings uncover the remarkable metabolic plasticity of the mammalian embryo, demonstrating its capacity to sustain growth independently of maternal inputs from the establishment of the body plan through the onset of the fetal period. Moreover, they highlight the use of long-term ex utero culture as a unique framework for dissecting the mechanisms that shape embryogenesis under physiological and experimentally perturbed conditions, while functionally uncoupling embryonic programs from maternal and placental influences.

developmental biology↗

bioRxiv2026

Midgestation metabolic constraint in purine metabolism drives distinct strategies for placenta and fetal growth

Purine nucleotides are essential for mammalian development1,2. Purine monophosphates support cell signaling and proliferation and are synthesized by cells through either de novo synthesis or a salvage pathway3. We previously identified a midgestational metabolic transition in mice (gestational days gd10.5-11.5) characterized by changes in purine metabolism4. Midgestation is a period of rapid growth for placenta and embryo, yet it remains unclear how the placental tissues expand without directly competing with the embryo for biosynthetic resources. Here, we show that this midgestational metabolic transition is associated with a marked reduction in embryonic expression of purine salvage enzymes, which constrains embryonic metabolism and leads to different strategies for purine synthesis between the placenta and embryo. Midgestation embryos are unable to engage the purine salvage pathway even when de novo purine synthesis is blocked either in vivo or in ex utero embryo culture, whereas placental tissue and trophoblasts retain the capacity to use either pathway. Disruption of de novo purine synthesis in mice causes reduced embryonic growth, impaired axial elongation, and abnormal brain and placental development, which are only partially rescued by supplementation with purine salvage precursors. In human placenta, trophoblast stem cells readily switch between the de novo and salvage pathways based on nutrient availability, and syncytiotrophoblasts (STB) preferentially rely on the salvage pathway. We identified guanosine monophosphate (GMP) as a metabolic checkpoint regulating STB differentiation, with insufficient GMP levels causing degradation of the small GTPase Rheb and failure of mTOR activation. Supplementation of purine salvage substrates restored GMP synthesis and STB differentiation in humans, but not mice. Further, in vivo measurements in humans revealed that maternal circulating hypoxanthine decreases during pregnancy and is further reduced in women with clinically small placentas, highlighting the role of hypoxanthine in supporting placental growth. These results uncover compartmentalized purine salvage between the embryo and placenta as a mechanism that limits competition for biosynthetic resources and enables coordinated growth during mammalian development.

developmental biology↗

bioRxiv2026

Functional impact of PCSK9 variants on LDL uptake in a knockout hepatic model

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a central regulator of low-density lipoprotein (LDL) cholesterol metabolism, yet the functional consequences of many clinically observed PCSK9 variants remain unknown. To establish a rigorous system for quantitative variant assessment, we generated a PCSK9 knockout (KO) HepG2 cell line through CRISPR/Cas9-mediated deletion of exons 2-8, effectively removing both the prodomain and catalytic regions required for PCSK9 function. This null background enabled systematic functional mapping of wild-type (WT) PCSK9 and multiple clinically relevant variants representing well-characterized, recurrent, and previously understudied alleles. Functional assays revealed pronounced heterogeneity among variant activities. The classical gain-of-function (GOF) variants D374Y and R496W exhibited robust suppression of LDL uptake, whereas A443T--an infrequently reported and previously uncharacterized variant--demonstrated a loss-of-function (LOF)-like phenotype with significantly enhanced LDL uptake. Additional poorly characterized variants, including V4I, R104C/V114A, and R496W/N425S, displayed minimal functional profiles, providing novel mechanistic insights. Surface LDL receptor (LDLR) levels generally correlated with LDL uptake but revealed unique patterns for specific variants. This KO-based rescue system provides a high-resolution framework for mechanistic classification of both established and poorly characterized PCSK9 variants, bridging the gap between genetic discovery and functional interpretation while supporting precision lipid-lowering strategies.

biochemistry↗

bioRxiv2026

A mouse-adapted Yezo virus model for antiviral testing in immunocompetent mice

Emerging tick-borne orthonairoviruses pose a growing public health threat, yet few animal models fully recapitulate human disease. Here, we report the development of a mouse-adapted Yezo virus (MA-YEZV) strain that causes lethal infection in immunocompetent mice, mirroring key clinical features of human infection, including thrombocytopenia, leukopenia, and severe liver injury. Serial passaging of YEZV in C57BL/6J mice selected for 31 non-synonymous mutations, enhancing viral replication and pathogenicity. MA-YEZV exhibited broad tissue tropism, with the highest viral loads in the liver, and induced a robust inflammatory response marked by elevated proinflammatory cytokines (e.g., IFN-{gamma}, TNF-, IL-6) and inflammasome activation. Ribavirin treatment effectively suppressed viral replication, prevented mortality, and mitigated tissue damage, whereas remdesivir showed no efficacy. This model provides a critical tool for studying YEZV pathogenesis and antiviral development, while the identified mutations offer insights into viral adaptation and virulence mechanisms. Our findings underscore the potential of MA-YEZV as a platform for evaluating countermeasures against emerging orthonairoviruses.

microbiology↗

bioRxiv2026

Functional Type I and Type II interferon crosstalk restricts progenitor exhausted CD8 T cells through spatial exclusion and checkpoint enforcement

Type I interferon (IFN-I) and interferon-{gamma} (IFN{gamma}) are central regulators of antiviral immunity, yet how they cooperatively govern CD8 T cell fate during chronic infection remains unresolved. Here, we uncover a previously unrecognized, spatially encoded interferon circuit that actively constrains progenitor exhausted CD8 T cells (Tpex) during chronic LCMV infection. Persistent IFN-I signaling indirectly restricts Tpex expansion by enforcing their sequestration within PDL1-rich B cell niches of lymphoid tissue and by suppressing T cell-derived IFN{gamma}. Blockade of IFN-I signaling enables Tpex migration into T cell zones of splenic follicles driving IFN{gamma} production, which in turn sustains PDL1 expression on myeloid cells to re-impose local inhibitory pressure. Combined IFN-I and IFN{gamma} blockade disrupts this feedback, promoting coordinated niche redistribution of Tpex and checkpoint remodeling that drives robust Tpex expansion. Single-cell transcriptomics reveal that this layered IFN-I-IFN{gamma} interplay establishes a regulatory balance that constrains Tpex proliferation while preserving effector-like transcriptional programs in their progeny effector CD8 T cells, ultimately preventing premature terminal differentiation. Thus, interferons orchestrate the coordinated T cell-myeloid regulatory circuit that integrates tissue organization, cytokine feedback, and checkpoint control to regulate CD8 T cell exhaustion during chronic infection.

immunology↗

bioRxiv2026

Connectome lateralization in autism across the first 14 years: heterogeneity related to developmental stage, hemisphere, and pathophysiology

Hemispheric lateralization is fundamental feature to neurodevelopment, yet its dynamic evolution in autism across childhood and underlying molecular mechanisms remain unknown. Thus, using a large-scale resting-state fMRI dataset (n = 1553, ages 1-14), we investigated developmental heterogeneity in connectome lateralization. At the group level, abnormalities in dynamic connectome lateralization strength (DCLS) progressed from focal patterns in early childhood ([≤] 6 years) to widespread distributions by late childhood ([≤] 14 years), independent of symptom severity. The late-stage patterns were validated using the ABIDE dataset (n=153). Late childhood also showed marked increases in inter-individual heterogeneity. These alterations were significantly associated with clinical phenotypes, transcriptomic profiles, and multiple neurotransmitter systems, with distinct patterns across childhood groups. Our findings reveal a developmentally dynamic trajectory of connectome lateralization in autism and highlight late childhood as a critical window for stage- and individual-specific interventions tailored to substantial individual heterogeneity.

neuroscience↗

bioRxiv2026

PantheonOS: An Evolvable Multi-Agent Framework for Automatic Genomics Discovery

The convergence of large language model-powered autonomous agent systems and single-cell biology promises a paradigm shift in biomedical discovery. However, existing biological agent systems, building upon single-agent architectures, are narrowly specialized or overly general, limiting applications to routine analyses. We introduce PantheonOS (https://PantheonOS.stanford.edu), an evolvable, privacy-preserving multi-agent framework designed to reconcile generality with domain specificity. Critically, PantheonOS enables agentic code evolution, allowing evolving state-of-the-art batch correction and our reinforcement-learning augmented gene panel selection algorithms to achieve super-human performance. PantheonOS drives biological discoveries across systems: uncovering asymmetric paracrine Cer1-Nodal inhibition in proximal-distal axis formation of novel early mouse embryo 3D data; integrating human fetal heart multi-omics with whole-heart data to reveal molecular programs underpin heart diseases; and adaptively selecting virtual cell models to predict cardiac regulatory and perturbation effects. Together, PantheonOS points towards a future where scientific discoveries are increasingly driven by self-evolving AI systems across biology and beyond. Websitehttps://pantheonos.stanford.edu Ecosystemhttps://github.com/aristoteleo SummaryLarge language model-powered agent systems are driving a paradigm shift in scientific discovery by automating, scaling, and accelerating data analysis. This transformation is particularly profound in biology, where the rapid expansion of single-cell and spatial genomics has effectively reshaped the field into a data-intensive science. However, existing biological agent systems are typically constrained to single-agent designs, are narrowly specialized, or are overly general without sufficient domain expertise, limiting their applicability to routine or shallow analyses. Here, we introduce PantheonOS (https://pantheonos.stanford.edu), an evolvable, privacy-preserving, and general-purpose multi-agent framework designed to reconcile generality with deep domain specificity. PantheonOS provides an abstract, extensible architecture that enables customized agent composition and supports end-to-end single-cell and multi-omics analysis, spanning reinforcement-learning-augmented gene panel design, raw FASTQ processing, multimodal data integration, and three-dimensional spatial genomics reconstruction. Central to this framework, Pantheon-Evolve enables agentic code evolution, allowing the system to autonomously improve state-of-the-art batch-correction algorithms and new reinforcement-learning based gene panel design algorithms, achieving performance beyond manually designed baselines. We demonstrate the power of PantheonOS across multiple biological domains. In early mouse embryogenesis, PantheonOS automatically reconstructs three-dimensional spatial gene expression landscapes and resolves asymmetric Cer1 expression and paracrine Cer1-Nodal inhibition, revealing a robust proximal-distal axis at embryonic day six (E6.0). In human development, PantheonOS integrates fetal heart single-cell multi-omics with whole-heart 3D MERFISH+ data at post-conception week 12, uncovering spatially resolved molecular programs underlying heart disease ontogeny. Finally, an intelligent model-routing mechanism enables PantheonOS to adaptively select optimal virtual cell models across heterogeneous tasks, revealing minimal regulatory networks of cardiogenesis and predicting spatially resolved perturbation effects in the developing heart. Together, PantheonOS establishes a foundation for fully automated, evolvable, and domain-aware agentic analysis in genomics, and points toward a future in which scientific discovery is increasingly driven by self-improving AI systems across biology and beyond.

bioinformatics↗

bioRxiv2026

Stool Metabolomics Reveals Catecholamine and Tryptophan-NAD+ Pathway Alterations in Autism Spectrum Disorder

Gut-brain axis dysregulation and microbiome-linked metabolic disturbances have been implicated in autism spectrum disorder (ASD), yet gut-derived neuroactive metabolites remain incompletely characterized. We applied targeted liquid chromatography-tandem mass spectrometry in a cross-sectional case-control study to quantify 18 stool metabolites related to catecholamine synthesis, GABAergic signaling, and tryptophan (Trp) and NAD+ metabolism in 59 participants (32 ASD, 27 non-ASD controls). Group differences were evaluated using log2 fold change and covariate-adjusted linear models. Random forest classifiers with five-fold cross-validation assessed multivariate discriminative performance, and within-group Spearman correlations examined metabolic network organization. Norepinephrine exhibited the largest elevation in ASD, while dopamine and tetrahydrobiopterin showed nominal group effects consistent with altered BH4-dependent catecholamine metabolism. Among individual metabolites, tetrahydrobiopterin, GABA, and kynurenine were the most informative, and their combination achieved an area under the receiver operating characteristic curve of 0.737 (95% confidence interval, 0.603 to 0.871). Correlation analyses revealed conserved lithocholic acid-deoxycholic acid coupling in both groups. In controls, Trp correlated with kynurenine, whereas ASD showed expanded Trp associations with GABA, norepinephrine, anandamide, and nicotinic acid, consistent with reorganization of Trp-NAD+ precursor pathways. These findings identify coordinated, gut-linked metabolic differences in ASD and define a metabolite signature reflecting altered catecholaminergic and Trp-related network structure. ImportanceAutism spectrum disorder is currently diagnosed using behavioral assessments, and objective biological measures are limited. The gut microbiome produces many small molecules that can influence brain development and function, but the specific metabolites involved in ASD remain unclear. Using targeted analysis of stool samples, we identified changes in metabolites related to neurotransmitter synthesis and tryptophan metabolism and showed that their relationships form distinct metabolic networks in individuals with ASD. A small panel of metabolites provided moderate ability to distinguish ASD from controls. These results suggest that gut-derived metabolites capture biologically meaningful variation in ASD and may help guide future studies aimed at understanding gut-brain communication and developing noninvasive biomarkers.

microbiology↗

bioRxiv2026

Stemona genomes illuminate fatty acid partitioning between seeds and elaiosomes mediating wasp dispersal

O_LISeed dispersal by wasps (vespicochory) is documented in five angiosperm families, with phylogenies suggesting that most vespicochorous lineages evolved from ant-dispersed (myrmecochorous) ancestors. While recent work has identified cues attracting wasp dispersers, the molecular basis remains unclear. C_LIO_LITo shed light on the molecular basis of vespicochory, we generated chromosome-level genomes for the wasp-dispersed Stemona tuberosa, and its close ant-dispersed relative S. mairei. Combining comparative genomic, transcriptomic, lipidomic, and functional analyses, we ask (i) how chemical elaiosome differentiation occurs during seed development, and (ii) how key mutualism-associated genes evolved in Stemona. C_LIO_LIWe show that elaiosomes up-regulate stearoyl-ACP {Delta}9 desaturases (SAD) and accumulate oleic acid and 1,2-diolein, which serve both as food rewards and as precursors for CER1/3-mediated biosynthesis of (Z)-9-tricosene, the key wasp attractant. By contrast, high expression of FatB and DGAT1 in seeds is associated with medium-chain fatty acids (MCFAs) production. Comparative genomics indicates conservation of these genes across Stemona, with S. tuberosa-specific FatB expansion and SAD/CER1/3 repertoire divergence. C_LIO_LIOur work supports a model for elaiosome-seed fatty-acid differentiation linking recruitment and nourishment in vespicochory. Given that oleic acid and 1,2-diolein are also key cues in myrmecochory, this shared biochemical basis may help explain how vespicochory evolves from ant-dispersed ancestors. C_LI

evolutionary biology↗

bioRxiv2026

Enhanced Hi-C Capture Analysis reveals complex regulatory architecture at the PICALM-EED locus for Alzheimer Disease

ObjectiveBoth the phosphatidylinositol binding clathrin assembly protein gene (PICALM) and the embryonic ectoderm development gene (EED) have been implicated as causal genes driving a genome-wide association for Alzheimer disease (AD) risk. We employed a new virtual approach using genome-wide chromatin interactions (Hi-C) called enhanced Hi-C Capture Analysis (eHiCA) to identify the genes and regulatory regions that are driving this important AD risk association. MethodsHi-C data from the frontal cortex of eight AD patients, as well as inducible pluripotent stem cell-derived microglia and spheroids of AD and control patients were used. We applied 14 eHiCA baits each containing a GWAS SNP to identify the cis regulatory interactions in this GWAS locus at a 5kb resolution. ResultsThe baits derived from the GWAS associated haplotype primarily interacted with the PICALM promoter and the large cis-regulatory elements cluster (CREe) lying upstream of the EED promoter. The EED promoter interacts with PICALM gene body and promoter region but not directly with the associated risk haplotype. Although the AD-associated variants segregate together as a haplotype in the population, each bait exhibited distinct functional chromatin interactions. InterpretationThe PICALM gene is the primary driver of the association in microglia along with the CREe locus. Different SNPs in a segregating haplotype can display different physical Hi-C interactions. This study demonstrates that eHiCA can help resolve the casual genes driving complex GWAS associations, opening new pathways to study Alzheimer disease and other disorders.

genomics↗

bioRxiv2026

The diversity of lesion network mapping findings

Lesion network mapping (LNM) has emerged as a popular framework to map the network mechanism of brain disorders using lesions and normative brain connectome (NBC)1. It was first demonstrated in neurological symptoms and was rapidly extended to a broad range of brain disorders in the past decade. A recent study by Van den Heuvel et al. questioned the methodological foundations of LNM2. We here raise concerns regarding their errors and biases in the methodology and visualization. The conclusion of that study--LNM maps circumscribed brain changes mostly to one and the same outcome--is not supported by the data presented.

neuroscience↗

bioRxiv2026

TCR signal strength determines Treg instability and discrimination of self versus non-self antigens

Regulatory T cells (Tregs) expressing autoreactive T-cell receptors (TCRs) maintain immune self-tolerance, yet their fate upon antigen encounter remains unclear. Although selected in the thymus for high-affinity self-recognition, the cross-reactive nature of the TCR repertoire allows some Tregs to also recognize foreign antigens with high affinity. Here, we identify cross-reactive destabilization, a process in which high-affinity recognition of foreign antigens erodes Treg stability and redirects lineage fate. Using a thymic-derived Treg (tTreg) TCR capable of recognizing both self and foreign antigens distinct from the self-ligand that mediated its thymic selection, we show that stimulation with high-affinity non-self agonists induces Foxp3 loss and conversion into effector-like ex-Tregs, whereas self-antigen stimulation preserves lineage stability. Treg instability also increases with age and correlates with activation, suggesting that cumulative foreign-antigen exposure drives this process. These findings reveal a signal-strength-dependent model in which strong TCR engagement induces cross-reactive destabilization to balance immune responsiveness and self-tolerance. One Sentence SummaryForeign antigen-driven destabilization of Treg cells balances immunity and tolerance

immunology↗

bioRxiv2026

Distinct allosteric remodeling of HIV-1 Env dynamics on virions by gp41-directed antibodies reveals two modes of neutralization

HIV-1 envelope glycoprotein (Env), a gp120-gp41 trimer, undergoes coordinated conformational changes that drive membrane fusion and allow immune evasion by transiently concealing neutralization-sensitive epitopes. Most broadly neutralizing antibodies (bNAbs) target gp120, whereas a distinct subset recognizes conserved gp41 regions, such as the fusion peptide and the membrane-proximal external region; however, their impact on Env dynamics and associated neutralization mechanisms remains unclear. Using bioorthogonal tagging for single-molecule FRET, we monitored real-time bNAb-induced conformational sampling of Env on intact virions. Most gp41-directed bNAbs allosterically stabilized the prefusion-closed (PC) state, whereas the bivalent 10E8.4/iMab favored both PC and CD4-bound open (predominant) states. Antibodies redistributed the conformational populations of Env with modest kinetic effects, preserving the sequential transition pathway. These findings reveal two modes of neutralization for gp41-directed antibodies: fixing the prefusion-closed conformation and opening it, in both cases via long-range allosteric control of Env dynamics.

microbiology↗

bioRxiv2026

High-PepBinder: A pLM-Guided Latent Diffusion Framework for Affinity-Aware Target-Specific Peptide Design

Peptides, as therapeutic molecules, offer unique advantages in targeting complex protein surfaces, yet their rational design remains limited by the vastness of the sequence space and the constraints of traditional approaches. Here, we propose High-PepBinder, a sequence-only conditional diffusion framework for target-specific peptide generation. Guided by the target protein sequence, High-PepBinder adopts a dual encoder architecture that integrates protein language models (pLMs) with the diffusion model. This approach cascades the peptide generation model with an affinity classifier and enables the generation process to capture affinity-related features of the peptides through lightweight joint optimization. Due to the scarcity of protein-peptide affinity data, we constructed PepPBA, to our knowledge the most comprehensive dataset to date, and established a structure- and physics-based screening pipeline to prioritize top candidates. Results show that High-PepBinder demonstrates competitive performance across multiple peptide generation and affinity-related tasks. For representative targets, including KEAP1, XIAP, and EGFR, the generated peptides preserve key binding geometries and interface patterns of reference peptides in predicted complexes, while maintaining sequence diversity and favorable predicted properties. Overall, High-PepBinder contributes toward a general and sequence-only strategy for peptide design, offering a computational framework for expanding peptide discovery against challenging targets.

bioinformatics↗

bioRxiv2026

Preparation and application of YFV-17D-derived Anterograde Trans-neuronal Viral Vectors for Neuroscience Research

Trans-neuronal viruses that spread between synaptically connected neurons have become invaluable tools in neuroscience, enabling circuit mapping and targeted delivery of genetic material to cells within defined pathways. Although most available trans-neuronal viral tracers propagate retrogradely, an anterograde trans-neuronal virus that spread from presynaptic to postsynaptic neurons would substantially expand experimental capabilities. We previously demonstrated that YFV-17D--a live attenuated yellow fever vaccine used clinically for decades--spreads anterogradely along neuronal circuits. We further developed a suite of recombinant YFV-17D-based vectors for diverse applications, including tracing monosynaptic projectome of defined neuronal cell types, multiplex mapping of parallel pathways, and trans-neuronal genetic manipulation with minimal neurotoxicity. We have now tested and optimized procedures for vector production and application. Based on these optimizations, here, we present a two-part guide for preparing and deploying this viral vector system to map brain connectivity. The first part describes the molecular biology and cell culture workflows required to generate high-quality viral vectors, yielding titers of [~]1 x 10^10 to 5 x 10^11 genomic copies per milliliter within approximately two weeks. The second part outlines optimized animal procedures, including intracranial injections, perioperative care, and experimental considerations tailored to specific aims and vector variants. Depending on the application, efficient trans-neuronal tracing can be achieved within 1-4 weeks following delivery.

neuroscience↗

bioRxiv2026

Abalone genomics reveals an ancient asymmetry axis and the multifunctionality of the mantle

Gastropod diversification represents one of the most spectacular evolutionary radiations, underpinned by a fundamentally asymmetric body plan and diverse pigmentation patterns. To understand the genetic underpinnings of these cardinal traits, we constructed a chromosome-level genome assembly for the rainbow abalone, Haliotis iris. Integrating systematic genomics, histoembryology, and molecular assays, we uncover an ancient regulatory axis, conserved for over 544 million years, in which the long non-coding RNA lncRNA1 functions as a competing endogenous RNA to shield pitx transcripts from miRNA-mediated degradation, thereby driving the establishment of asymmetric body patterning, including the mantle. Furthermore, we identify a wnt-mitf-tyr cascade as the driver of melanogenesis and demonstrate that the mantle is the primary site of melanin synthesis. Concurrently, we reveal the mantle as a multifunctional organ possessing mechanosensory capabilities. These findings elucidate the ancient genetic toolkit governing trait evolution in gastropods. TeaserA deeply conserved RNA switch directs gastropod body plans and reveals the mantles hidden talents.

genomics↗

bioRxiv2025

Vitreous Inflammation as an Early Indicator of Retinal Ganglion Cell Loss Following Acute Optic Nerve Injury in Mice

Retinal ganglion cell (RGC) degeneration in optic neuropathies is often preceded by neuroinflammatory changes, yet the earliest in vivo indicators of this process remain poorly defined. Here, we identified vitreous hyperreflective foci (VHRFs) by visible-light optical coherence tomography (vis-OCT) as an early inflammatory signature of RGC injury. Longitudinal vis-OCT imaging after optic nerve crush (ONC) revealed that VHRFs emerged as early as 6 hours post-injury and peaked before the significant RGC loss. Confocal analysis showed that these VHRFs corresponded to activated amoeboid microglia undergoing vertical migration from the outer to inner retina and horizontal movement toward the optic nerve head area. Similar amoeboid microglia were also observed in the anterior segment, suggesting a global ocular inflammatory response to the ONC injury. RNAscope in situ hybridization further demonstrated elevated IL-1{beta} expression in vitreous amoeboid microglia. Moreover, pharmacological blockade of IL-1 signaling with an IL-1 receptor antagonist significantly reduced VHRFs, suppressed microglial migration, and delayed RGC loss. Taken together, our findings identify VHRFs as a previously unrecognized early danger signal for RGC degeneration and highlight IL-1-mediated inflammation as a tractable early therapeutic target for preventing RGC degeneration and vision loss. Graphical Overview O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/694725v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1598c4aorg.highwire.dtl.DTLVardef@9637borg.highwire.dtl.DTLVardef@623bf4org.highwire.dtl.DTLVardef@14e21ce_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗