Biology subjects

Lai, L.

Publications and source records attributed to Lai, L..

At least 19 recordsLinked to original sources

bioRxiv2026

Cytoplasmic genomes change allelic expression bias in plant seeds independently of parental imprinting: evidence for cytonuclear regulatory epistasis in Arabidopsis thaliana

Cytoplasmic genomes play critical roles in plant cells, yet their potential contribution to regulation of the nuclear genome remains largely unexplored. Here, we examine how cytoplasmic genotype affects allelic dominance at nuclear loci by identifying allele-specific expression in hybrid plant lines in which cytoplasmic genomes have been swapped between accessions. After developing a bias-free ASE analysis pipeline based on dual pseudo-genome alignment, we determined ASE across 48 RNA-seq datasets of the model plant, Arabidopsis thaliana and distinguished between allelic bias under the control of the genotype and or the cytoplasm. Of 7,997 nuclear genes for which informative SNPs could be mapped, 2,702 displayed allelic imbalances, the great majority controlled by the nuclear background. However cytoplasmic interactions with nuclear genotype were found to regulate ASE at 24 genes. We also tested interactions with genomic imprinting, a specific form of ASE in which parental inheritance determines expression state, within seed transcriptomes: while we detected both novel and previously-reported imprinted genes, only three genes (VFB1, ANNAT3, ENODL2) exhibited both parent-of-origin bias and cytoplasm-responsiveness. This indicates that these two parental inheritance mechanisms are largely independent, with implications for maternal-cytoplasmic coadaptation theories. Interestingly, genes subject to cytoplasmic ASE were enriched in the ascorbate and aldarate metabolism pathway, with the highest ASE biases found in GAE4 and UGD3. We conclude that cytoplasmic variation can selectively alter expression of nuclear-encoded alleles and that this may represent a novel source of control of cellular energy balance and metabolic signalling pathways.

genetics↗

bioRxiv2026

Establishment of Rabbit Formative-like Pluripotent Cells by Bidirectional Modulation of WNT Signaling Pathway

The generation of embryonic stem cells (ESCs) with full developmental capacity and robust chimera-forming potential remains a major bottleneck for most non-rodent mammalian species including rabbits, an important animal both for biomedicine and agriculture. Formative pluripotency is a unique intermediate state bridging the naive and primed pluripotent states, which is defined by distinct molecular signatures, intrinsic competence for primordial germ cell (PGC) specification, and unique developmental adaptability to early embryonic microenvironments. Here, we established a novel culture medium termed KFiC, which could bidirectionally and coordinately modulate the WNT/{beta}-catenin signaling pathway via combined treatment of WNT activator CHIR99021 and inhibitor IWR-1. The KFiC culture system enables efficient derivation and stable long-term self-renewal of rbESCs with consistent formative-like pluripotent characteristics. KFiC-cultured rbESCs (KFiC-rbESCs) form compact, undifferentiated colonies, maintain intact genomic stability, and recapitulate the transcriptional landscape of pre-implantation epiblast cells, accompanied by sustained high expression of the core formative pluripotency marker OTX2. Functionally, KFiC-rbESCs possess efficient PGC differentiation competence and extensively contribute to embryonic development after microinjection into rabbit morulae, displaying their superior developmental plasticity. Notably, the KFiC system can stabilize an intermediate formative-like pluripotent state in mouse, human, and porcine pluripotent stem cells, and KFiC-adapted mouse ESCs retain potent chimera-forming ability. Collectively, this study establishes a reliable culture platform for generating and maintaining formative-like rbESCs. This cross-species compatible system provides a promising foundation for further optimizing naive-level pluripotency in rbESCs and facilitates the generation of genetically engineered rabbit disease models.

developmental biology↗

bioRxiv2026

BCKDK Inhibitors Directly Antagonize Angiotensin II Type 1 Receptor and Induce Vasodilation Independently of BCAA Catabolism or BCKDK

Branched-chain amino acids (BCAA) have been implicated in diabetes and heart failure, leading to ongoing clinical trials with inhibitors of BCKDK, a key regulator of BCAA catabolism. We have previously shown that these inhibitors promote vasodilation and lower blood pressure, well-known cardioprotective effects, but how this occurs remained unclear. We show here, using explanted vessels, in vivo hemodynamics and telemetry, and genetically modified mice, that the vasodilatory effect of BCKDK inhibitors is direct, rapid, independent of nitric oxide, independent of BCAA catabolism, and most strikingly, independent of BCKDK itself. Instead, we demonstrate, using structural and biochemical studies, that BCKDK inhibitors directly antagonize the angiotensin II type I receptor (AT1R) and consequent angiotensin-mediated vasoconstriction. These data demonstrate a strong off-target effect of BCKDK inhibitors, independent of BCAA or BCKDK, which may explain their cardioprotective effects but also questions if this protection would be additive to existing AT1R blockers.

physiology↗

bioRxiv2026

Policy regularization as a unifying theory of the striatal division of labor in learning

Learning novel behaviors requires balancing previously learned actions with the ability to flexibly adapt to changing reward contingencies. This trade-off is well documented in the division of labor between dorsolateral striatum (DLS), which promotes selection of cached, history-dependent actions, and dorsomedial striatum (DMS), which supports flexible learning as reward contingencies change. Here, we propose policy regularization as a general computational principle for understanding this division. Capacity-limited agents face a fundamental trade-off between maximizing reward and minimizing the cost of deviating from a default policy that caches frequently used action transitions. We formalize this trade-off as a KL-regularized reward objective in which a flexible controller (DMS) incurs a cost for diverging from a history-dependent default (DLS). The resulting optimal policy is a combination of a reward-driven action value, continuously updated by DMS, and a default policy conditioned on action history, cached by DLS. In practice, DLS consolidates the action transitions shaped by DMS's reward-driven value learning, so DLS preserves behaviors that were once optimal even when reward contingencies change, producing robust but inflexible action selection and effectively "regularizing" DMS-driven learning. We show that a single model with one shared parameter set and consistent lesion rules provides a unifying explanation for the functional organization of the striatum, reproducing canonical DLS-DMS dissociations in outcome devaluation, serial spatial reversal, skilled action sequencing, and motor sequence execution tasks.

neuroscience↗

bioRxiv2026

siDiff: De Novo siRNA Design via Efficacy-Guided Discrete Masked Diffusion

Target-conditioned de novo siRNA design requires capturing both target mRNA binding context and internal siRNA sequence-activity rules. Traditional computational pipelines predominantly rely on discriminative prediction models that rank pre-filtered candidate pools. However, these approaches struggle with generalization on novel target genes and often overlook potent candidates due to dataset size constraints and motif overfitting. To reconcile generation precision with sequence diversity, we propose siDiff, an efficacy-guided discrete diffusion framework for target-conditioned de novo siRNA design. siDiff pairs a discrete-masked diffusion transformer--which models the underlying sequence distribution over functional duplexes--with a mask-robust efficacy guidance model. During inference, we introduce a biology-aware, three-stage sampling mechanism that performs structural candidate filtering, dynamic unmasking guidance, and cluster-aware redundancy mitigation. This dual mechanism enables the diffusion process to explore broad sequence spaces while the efficacy model prevents distributional shift toward non-functional candidates. Extensive experiments across four datasets, including the public Takayuki benchmark and three curated patent datasets, demonstrate that siDiff significantly outperforms state-of-the-art discriminative baselines and discrete diffusion models, achieving relative hit-rate improvements of over 30% and demonstrating superior generalization on out-of-distribution gene targets. The source code and related materials are available at https://github.com/cybericha/siDiff.

bioinformatics↗

bioRxiv2026

Antagonism of stress granules key for SARS-CoV-2 infection and pathogenesis.

Viruses must subvert host responses to facilitate successful infection. While most antiviral responses are associated with interferons, stress granules (SG) are another barrier to viral infection by inducing translation arrest. To combat SG activity, viruses have evolved mechanisms to disrupt formation and disassemble these complexes. Our prior studies identified residues in SARS-CoV-2 NSP3 (Y138/F145) and nucleocapsid (F17) that independently antagonize SG activity. Disrupting these key residues in NSP3 or nucleocapsid attenuated viral replication, but only modestly impacted in vivo pathogenesis suggesting overlap in SG antagonism partially compensate for the individual losses. In this study, we evaluated a SARS-CoV-2 mutant (YF/F17A) that combines the NSP3 and N mutations. We find that loss of both SG antagonizing functions attenuates SARS-CoV-2 replication in vitro. While no changes are seen in type I IFN sensitivity, attenuation corresponds to increased induction of SGs. Importantly, the SARS-CoV-2 YF/F17A mutant has significant attenuation in vivo with reduced viral replication, less weight loss, and limited immune pathology. Notably, infection with the YF/F17A mutant stimulated less interferon and inflammation. Despite these muted host responses, the YF/F17A mutant stimulated robust protection against subsequent challenge with WT SARS-CoV-2. Overall, the study highlights the importance of SG control for SARS-CoV-2 infection and offers a novel, interferon independent target for vaccination and therapeutic treatment going forward. ImportanceThis study demonstrates that SARS-CoV-2 uses multiple mechanisms to block host stress granules during infection. Knocking out both N and NSP3 mediated antagonism of stress granules attenuates viral replication and disease caused by SARS-CoV-2. Importantly, while most therapeutics target key viral processes or induce interferon pathways, this study shows stress granule activation as a novel approach to attenuate and treat coronavirus infection.

microbiology↗

bioRxiv2026

OCOO-T : A SIMPLE AND SCALABLE VIRTUAL CELL MODEL FOR TRANSCRIPTIONAL PERTURBATION RESPONSE PREDICTION

Predicting single-cell transcriptional responses to genetic, chemical and cytokine perturbations is a fundamental challenge in computational biology and AI Virtual Cell (AIVC) modeling, with direct implications for drug discovery and the elucidation of gene regulatory networks. Existing approaches often rely on auxiliary cell-state encoders, hierarchical variational autoencoders, dedicated Transformer encoder-decoder modules, or gene-interaction priors to compress high-dimensional expression profiles into latent representations. While effective, these designs increase architectural complexity and may limit scalability and generalizability. This paper introduces OCOO-T 1, a minimalist flow-matching-based AIVC model for transcriptional perturbation response prediction. OCOO-T utilizes a vanilla Transformer stack that operates directly on continuous gene expression profiles and formulates perturbation response prediction as a continuous-time denoising process. Perturbation embeddings, dosage information, and cell-line/cell-type specificity are integrated through adaptive layer normalization and in-context tokens. Comprehensive evaluations on Tahoe100M, Replogle, and PBMC benchmarks demonstrate that OCOO-T achieves state-of-the-art performance across diverse perturbations and cell types while effectively scaling to long transcriptional profiles through patching and depatching of cellular contexts. By leveraging the simplicity of Transformer-based denoising for single-cell omics, OCOO-T provides an effective and scalable framework for in-silico cellular simulation.

bioinformatics↗

bioRxiv2026

Antigenic characterization of SARS-CoV-2 variants BA.3.2.1 and BA.3.2.2 in three animal models

BA.3.2, a variant of SARS-CoV-2 containing [~]40 mutations in its spike protein compared to its nearest ancestor, has spread globally since its first detection in South Africa in November 2024. Here, we report antigenic characterization of BA.3.2 viruses in three naive animal models, and visualize its antigenic phenotype in the context of SARS-CoV-2 evolution using antigenic cartography. We find that: (1) BA.3.2 is substantially antigenically divergent from existing SARS-CoV-2 variants; (2) infection with BA.3.2 in hamster and mouse animal models produces sera with lower homologous titer than infection with other variants. Both of these results may have implications for the selection of vaccine antigens.

microbiology↗

bioRxiv2026

Immunological imprinting shapes the cross-reactive antibody responses to the KP.2 and LP.8.1 vaccine doses

The emergence of the SARS-CoV-2 Omicron BA.2.86 subvariant, a lineage derived from the BA.2 strain, led to the 2024-2025 COVID-19 vaccine update to include KP.2 or related JN.1-lineage spike antigens. We evaluated the magnitude, breadth, and durability of humoral immune responses following a single KP.2 vaccine dose in a longitudinal cohort of 21 individuals up to six months. KP.2 vaccination increased spike-specific binding and neutralizing antibodies against the ancestral WA1 strain, alongside the BA.5, XBB.1.5, and KP.2 variants. Power law modeling estimated half-lives for WA1- and KP.2-specific IgG responses at 770 and 248 days, respectively. Additionally, the KP.2 dose increased IgG1 and IgG4 subclasses more than IgG2 and IgG3 responses to both spike proteins. Serum depletion experiments using WA1 or KP.2 proteins demonstrated most vaccine-elicited antibodies were cross-reactive. Consequently, KP.2 vaccine-induced antibodies retained broad neutralizing activity against recently circulating Omicron subvariants (BA.2.86, KP.3.1.1, XEC, LP.8.1, LF.7, XFG.3.12, PQ.1, BA.3.2.1, and RE.2). Using a live virus neutralization assay, XFG.3.12 showed the greatest reduction in neutralizing titers relative to KP.2 (4.2-fold). In a small subset, an LP.8.1 vaccine dose increased neutralizing activity against the matched variant while maintaining WA1 and KP.2 cross-reactivity, but only modestly increased antibodies to divergent variants BA.3.2.1 and RE.2. Ultimately, these data indicate the KP.2 mRNA vaccine generates durable, cross-reactive responses against current Omicron subvariants. However, ongoing spike evolution impacts neutralization of emerging lineages, highlighting the need for continued viral monitoring and timely vaccine updates. IMPORTANCESARS-CoV-2 continues to evolve, raising ongoing concerns about how well updated vaccines protect against emerging variants. This study evaluates antibody responses after KP.2 spike mRNA vaccine dose and shows that a single dose induces durable and broadly cross-reactive immunity against both earlier strains and recently circulating Omicron subvariants. Despite this breadth, reduced neutralizing activity against certain emerging variants indicates that ongoing antigenic changes can impact vaccine induced antibody effectiveness. These findings provide insight into how current vaccines perform over time and highlight the need to track viral evolution and update vaccine antigens to maintain broad protection against severe disease, hospitalization, and death.

immunology↗

bioRxiv2026

Targeting the AgMOBP1-PfSyn5 mosquito-parasite interface completely blocks malaria transmission

Malaria control remains constrained by an incomplete understanding of the molecular interactions that enable Plasmodium falciparum transmission within mosquito vectors. Although blood-stage parasite biology has been extensively studied, the mosquito-stage processes required for transmission are less well defined. Here, we characterize a previously unannotated Anopheles gambiae midgut factor, Midgut Ookinete Binding Protein 1 (AgMOBP1; AGAP008138), and define its role in parasite infection. AgMOBP1 is a membrane-associated protein localized predominantly to the apical surface of midgut epithelial cells, is induced by blood feeding, and appears restricted to anopheline mosquitoes. Functional infection assays showed that exogenous recombinant AgMOBP1 enhanced Plasmodium infectivity by increasing midgut oocyst burden, whereas anti-AgMOBP1 antibodies significantly reduced infection, establishing AgMOBP1 as a host factor that promotes transmission. Using biochemical interaction assays, we identified the parasite binding partner of AgMOBP1 as the P. falciparum syntaxin-5-like protein PfSyn5. Disruption of this interaction with anti-PfSyn5 polyclonal antibodies produced exceptionally potent transmission-blocking activity, with complete inhibition at 1 {micro}g/mL and an estimated IC50 of [~]3 ng/mL ([~]20 pM). This potency is approximately one million-fold lower than the total IgG concentration in normal human plasma. Together, these findings identify a critical mosquito-parasite molecular interface required for malaria transmission and establish the AgMOBP1-PfSyn5 axis as a promising target for transmission-blocking vaccines, monoclonal antibodies, and other intervention strategies. Significance StatementInterrupting malaria transmission requires a deeper mechanistic understanding of how Plasmodium parasites interact with their mosquito vectors. Here, we define a previously uncharacterized mosquito midgut factor, AgMOBP1, and identify its parasite binding partner, the Plasmodium falciparum membrane protein PfSyn5. We show that this molecular interaction is required for efficient parasite transmission to Anopheles mosquitoes. Remarkably, antibodies against PfSyn5 completely blocked transmission at low concentrations, revealing exceptional functional potency. These findings uncover a previously unknown mosquito-parasite invasion pathway and establish the AgMOBP1-PfSyn5 interface as a high-value target for transmission-blocking vaccines, monoclonal antibodies, and next-generation malaria control strategies.

microbiology↗

bioRxiv2026

CellChem: Cellular transcriptional responses reshape molecular representation space for efficient and multi-scale drug discovery

Despite decades of progress in computational drug discovery, deep learning-based molecular representation models remain largely structure-centric, assuming that chemical similarity approximates functional similarity. However, drug effects in cells are shaped not only by chemical similarity but also by molecular interactions in the cellular context. To capture this complexity, we introduce CellChem, a cellular-chemical representation-learning framework that learns cell-guided molecular representations of small-molecule actions within cells. By incorporating large-scale cellular transcriptional profiles during pretraining, CellChem reshapes molecular representation space from structure-centric to a balanced integration of structure and function. The learned CellChem molecular representations exhibit biologically meaningful geometric organization, such that distances between molecules encode not only structural similarity but also similarity in the cellular responses they elicit, independent of downstream tasks. Using downstream derivative models such as cell-guided compound-protein interaction prediction and drug-induced transcriptional response profile generation, CellChem supports highly efficient, multi-scale drug discovery, achieving significantly better performance than traditional models.

molecular biology↗

bioRxiv2026

Development of a BM7G((TKO/hCD46/hCD55/hTHBD/hEPCR) Donor Pig with Endogenous Promoter-Driven Transgenes for Xenotransplantation

Xenotransplantation offers a potential solution to the organ shortage crisis. Multi-gene modification of pigs, such as knockout of three carbohydrate antigen-related genes and expression of immunoprotective proteins, can significantly improve xenograft survival. However, existing strategies face challenges: transposon-based transgenesis may lead to unstable expression, while exogenous promoters used in site-specific integration are susceptible to epigenetic silencing, hindering long-term stable expression. Therefore, developing a donor pig model capable of sustained multi-gene expression is critical. To address this, CRISPR-Cas9 was used to knockout three major glycan antigen genes to eliminate hyperacute rejection. Subsequently, four human protective genes were site-specifically integrated into the porcine Rosa26 safe-harbor locus, with expression driven by the endogenous Rosa26 promoter and the THBD core promoter for long-term stable and tissue-specific expression, and the selection marker was removed using Cre/loxP. Results showed complete absence of the three glycan antigens in BM7G pigs, while the four protective proteins were stably expressed in vascular endothelial cells and major organs. Among them, hCD55 and hCD46 were widely expressed, while hTHBD and hEPCR showed vascular-specific expression. In-vitro assays confirmed that BM7G porcine endothelial cells significantly reduced human antibody binding, effectively inhibited complement-dependent cytotoxicity, and decreased thrombin-antithrombin complex formation. In conclusion, by combining xenoantigen knockout with endogenous promoter-driven expression of multiple human protective genes, a seven-gene modified pig model with low immunogenicity and synergistic protective function was successfully constructed, providing an important donor resource for xenotransplantation preclinical research.

immunology↗

bioRxiv2026

Dirty mice better recapitulate key features of mRNA vaccine immunogenicity observed in humans

Although specific pathogen free (SPF) mice have traditionally been used to test candidate vaccines, recent work has demonstrated that "dirty" mice with broad microbial exposure more appropriately recapitulate human immune responses. Using a model where lab mice are co-housed with pet store mice, we modeled SARS-CoV-2 mRNA vaccine responses in dirty and traditional SPF models. We found that dirty mice show reduced serum spike-binding antibody titers after prime and require a second booster dose to reach SPF-level spike antibody titers. Additionally, spike antibodies showed faster waning in dirty mice through 5 months post-vaccination, and neutralizing activity of these antibodies were reduced against Omicron variants, directly comparable with observations in humans. We further investigated the seasonality and consistency of pathogens in cohoused mice, and the impact of serial microbial exposure on our animal model system. We found that pathogen exposure and T cell activation remained consistent over time, and that a single co-housing event was sufficient to provide broad microbial exposure. This work demonstrates that the dirty mouse co-housing system is a promising, translationally representative approach to screen candidate mRNA vaccines for efficacy and durability prior to human clinical trials. Significance statementThe development of mRNA vaccines during the COVID-19 pandemic dramatically reduced hospitalization and death rates for infected individuals. However, booster vaccinations were required to achieve full efficacy, and protection waned over time. Our research leveraged a "dirty" mouse model to test whether SARS-CoV-2 mRNA vaccinations in animals with previous microbial exposure better modelled human immune responses. We found that dirty mice require a booster vaccination for full efficacy and experienced waning serum antibody titer over time. We propose this approach as a future model for robust preclinical mRNA vaccine testing.

immunology↗

bioRxiv2026

Porcine extended pluripotent stem cell-derived somite-like mesoderm cells with Dox-driven PAX7 are robust seed cell resource for facilitating production of cultured meat

Cultured meat technology, with its significant advantages of shortening meat production cycles, reducing natural resource consumption, minimizing the risk of zoonotic disease transmission, and enabling precise control over nutritional composition and texture, offers a novel alternative source for human meat consumption. One of the major challenges to produce cultured meat in large scale is how to establish high.quality seed cells, which should have long term proliferative capacities and are able to differentiate into muscles efficienuy with simple procedures. Here, we first established an engineered porcine expanded potential stem cells (Tet-On-PAX7 EPSCs) containing Tet-On regulated PAX7 gene. Then the Tet-On-PAX7 EPSCs were induced to somite-liKe mesodermal cells. These somite-liKe mesodermal cells can be expanded over 1025-fold even after 40 passages in-vitro culture while retaining strong myogenic potential. The somite-like mesodermal cells treated with DOX for one day would differentiate into muscle stem cells (Muses), and the later were able to differentiate into muscles with an efficiency of up to 90% within just 7 days in 11-FSDeDa without Dox. Moreover, when somite-liKe mesodermal cells were seeded on patterned scaffolds, microcarrier scaffolds, or cultured in anchorage-independent suspension, they maintained high efficiency in muscle differentiation, confirming their potential to be used as seed cells for scaled cultured meat production.

developmental biology↗

bioRxiv2025

FuzzAletheia: Mapping dynamic interaction landscapes of intrinsically disordered protein-ligand complexes to accelerate ligand optimization

Intrinsically disordered proteins (IDPs), representing more than 30% of human proteome, present great challenges in rational drug design due to their highly flexible conformations and dynamic interactions. Though their malfunction is linked to major diseases, IDPs are difficult to target. A critical roadblock lies in hit-to-lead optimization due to their dynamic interactions with hit compounds. Here we developed FuzzAletheia, an IDP-ligand dynamic binding pattern analyzer, to accelerate hit optimization. It analyzes the molecular dynamics simulation trajectories of IDP-ligand to cluster interactions into distinct spatiotemporal stable binding features, which are then visualized and quantified to provide insights into the dynamic binding orientation, strength, and stability. This analysis pinpoints modification sites on hit compounds for optimization. We applied FuzzAletheia to the disordered p53 transactivation domain 1 and its hit compound 1050. Guided by FuzzAletheia analysis, we designed and synthesized six derivatives of 1050 and the most potent compound achieved a 10-fold enhancement in activity, demonstrating its power to accelerate IDP hit optimization.

biophysics↗

bioRxiv2025

Slab-PTM: A Coarse-Grained Force Field Parameter Patch for Modeling Post-Translational Modification Effects on Biomolecular Condensates

Intrinsically disordered proteins (IDPs) play crucial roles in biomolecular condensate formation. While molecular dynamics simulations employing coarse-grained models have emerged as useful tools for studying IDP phase behavior, current force-field parameterizations remain limited in their ability to simulate post-translational modifications (PTMs), which are the critical regulatory elements of IDP involved condensation with profound biological implications. To address this gap, we developed interaction parameters for five common PTM types: phosphorylated serine (pSer), threonine (pThr), and tyrosine (pTyr); acetylated lysine (AcLys); and asymmetric dimethylarginine (aDMA). Using all-atom umbrella sampling simulations, we computed residue-specific potentials of mean force (PMFs) between modified and canonical amino acids. These PMF-derived parameters were systematically integrated into the established slab-geometry coarse-grained models (CALVADOS and Mpipi) via an additive module termed as Slab-PTM. Benchmark simulations demonstrate that Slab-PTM accurately captures the effects of PTMs on IDP phase behavior while remaining fully compatible with existing LLPS simulation frameworks. In addition, Slab-PTM enables the identification of molecular grammar elements through which PTMs modulate IDP-driven phase separation.

biophysics↗

bioRxiv2025

Lack of Reproducibility of Gulf War Illness-like Behavioral Effects in War-related Chemical Agents and Stressor Exposure Rat Models

Gulf War illness (GWI) is characterized by a range of neurological and neuropsychiatric symptoms, including chronic pain, fatigue, mood problems, and cognitive issues. The pathophysiology is associated with war-related environmental chemical exposure and psychological stress, which are known to disrupt glutamatergic synaptic structure and function. The goal of this study was to evaluate the efficacy of the investigational new drug LH-001, a candidate for enhancing tripartite glutamatergic synapses, in a rat model of GWI. We began by attempting to induce GWI-like phenotypes in rats using a previously published protocol involving exposure to specific chemical agents and mild stress. However, these efforts were unsuccessful, as the expected GWI symptoms were not observed. We then performed two protocol modifications--using more potent chemical exposures and higher stress levels--but were still unable to produce the desired phenotypes. Our results highlight significant issues with the reliability of current GWI rat models. A comparative analysis of other studies suggests that GWI-like behavioral effects, when induced in rats by chemical agents and stress, show a broader lack of reproducibility across different laboratories. This calls into question the robustness of current rat models for GWI and poses challenges for preclinical drug development.

neuroscience↗

bioRxiv2025

Derivation, Characterizations, and Applications of Rabbit Haploid Embryonic Stem Cells

Haploid embryonic stem cells (haESCs), which contain a single set of chromosomes, provide powerful systems for investigating gene function and creating gene-edited animal models. haESCs have been derived from several mammalian species including human, mouse and rats, yet not from rabbits. Here, we report the derivation of parthenogenetic haESCs of rabbit (rbPhESCs) using an optimized culture medium. These cells maintain a stable haploid karyotype during long-term culture and own pluripotency features comparable to diploid embryonic stem cells derived from rabbit fertilized embryos. By integrating gene trapping cassette into ROSA26 locus, rbPhESCs offer an ideal platform for high-throughput functional genomic screening, as shown in haESCs from other mammals. Consistent with their parthenogenetic origin, rbPhESCs durably preserve maternal-specific imprinting patterns even after extended culture in serum-containing conditions, providing a valuable platform for generating disease models deficient in maternally expressed imprinted genes. Therefore, our findings expand the repertoire of mammalian haESCs and establish rbPhESCs as a valuable platform for genetic studies and biotechnological applications in rabbits.

cell biology↗