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Li, G.

Publications and source records attributed to Li, G..

At least 55 records · Page 3Linked to original sources

Presynaptic mitochondria calcium uniporter promotes auditory temporal processing during sustained high-rate activity

Mitochondrial calcium uniporter (MCU) uptakes calcium into mitochondria to maintain intracellular calcium homeostasis, malfunction of which has been implicated in altered neuronal signaling and disease. Its role in synaptic transmission remains understudied, especially in intact neural circuits. We investigated MCU function at the auditory nerve endbulb of Held synapse and postsynaptic bushy neurons in the cochlear nucleus, using age-matched control and MCU knockout (KO) mice of either sex. Whole-cell voltage-and current-clamp recordings were acquired from acute brain slices to examine synaptic transmission and postsynaptic responses. We found that basal synaptic properties at the endbulb of Held were unchanged in MCU KO mice, whereas synaptic transmission during sustained high-rate activity was significantly altered with a shift toward increased asynchronous release. Similarly, MCU deficiency did not change the intrinsic membrane properties of postsynaptic bushy neurons, but significantly reduced the temporal precision of auditory nerve evoked spikes trains at high rates. These results demonstrate that MCU is largely dispensable under low-rate activity, presumably because its activation requires relatively high calcium concentrations. In contrast, during sustained high-rate activity, MCU becomes an important regulator of synaptic function by reducing asynchronous neurotransmitter release under elevated intracellular calcium. Particularly in the auditory system, where neurons routinely fire at high rates, MCU promotes temporal processing and thereby plays a key role in supporting auditory function. It suggests that impaired MCU function under pathological conditions may be an important mechanism underlying central auditory processing deficits, and consequently contributes to hearing loss. SIGNIFICANT STATEMENTMCU uptakes calcium into mitochondria to regulate intracellular calcium, yet its contribution to synaptic transmission and neural processing remain understudied. Using a MCU KO mouse model, we investigated the role of MCU in synaptic transmission and postsynaptic responses at the endbulb of Held synapses and postsynaptic bushy neurons in the cochlear nucleus. The results showed that MCU plays little role in basal synaptic transmission, but significantly reduces asynchronous vesicle release during sustained high-rate activity, consequently improving temporal precision of the signal processing. These findings define the roles of MCU under different activity levels at the intact endulb/bushy connection, and suggest that impaired MCU function may be a key mechanism underlying central auditory processing deficits, and consequently contributes to hearing loss.

neuroscience↗

Decoding and Targeting Coordinated CDKN1A and CDKN2A Senescence Programs in ECM-Dominant Cardiovascular Pathologies

Cellular senescence is a hallmark of aging and an emerging therapeutic target; however, its role as a context-specific driver of disease remains incompletely defined, and senolytic therapies have shown inconsistent clinical benefit. Here, we identify extracellular matrix (ECM)-dominant pathologies as a major class of senescence-driven disease, characterized by inflammation, matrix degeneration, and progressive tissue dysfunction. Using integrated single-cell transcriptomics, spatial profiling, and multiplex imaging across human specimens and murine models, we demonstrate that senescent fibroblasts, rather than canonical myofibroblasts, constitute the principal disease-driving cell state in myxomatous mitral valve disease (MMVD) and related conditions. These cells exhibit coordinated CDKN1A inflammatory and CDKN2A ECM-remodeling programs that form a feed-forward circuit linking immune activation to matrix disorganization and functional decline. Senescence extends beyond fibroblasts to endothelial and immune compartments, establishing a multicellular senescent milieu that reinforces intercellular crosstalk and disease progression. Senolytic treatment (dasatinib plus quercetin or fisetin) restores ECM architecture and improves cardiac function, outperforming pathway-specific anti-inflammatory and antifibrotic approaches. Cross-disease analyses further reveal conservation of this coordinated CDKN1A/CDKN2A senescence programs across multiple ECM-dominant cardiovascular diseases, including aortic aneurysm and calcific valve disease. Notably, in vivo single-cell transcriptomic profiling following multiple senolytic treatments provides whole-transcriptome resolution of context-dependent cellular responses. Collectively, these findings establish context-specific senescence as a central organizing mechanism in ECM-dominant diseases and support a shift from generalized anti-aging strategies toward precision senolytic prevention or therapy. Given that valvular and aortic diseases affect millions and increase markedly with age to a prevalence comparable to major cancers, these results indicate a potential solution to a substantial and underrecognized clinical burden.

Cell Biology↗

Single cell in vivo analysis of type I IFN and NK cell-mediated control of B cell infection densities during acute gammaherpesvirus infection

Immunodeficient patients are at risk of severe complications following infection with the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposis sarcoma-associated herpesvirus (KSHV). Due to the strict host specificity of human gammaherpesviruses, murine gammaherpesvirus 68 (MHV68) is widely used as an in vivo model to study gammaherpesvirus pathogenesis. While type I interferons (IFNs) and natural killer (NK) cells are known to contribute to antiviral defense during MHV68 infection, how these innate immune mechanisms control infection within lymphoid tissues at the level of individual infected cells remains incompletely understood. Here, we used an MHV68-DsRed reporter virus to visualize infected cells in the lymph nodes of wildtype and type I IFN receptor-deficient (Ifnar1-/-) mice by flow cytometry, immunohistochemistry, and two-photon microscopy. We found that type I IFN signaling plays a major role in limiting both local viral infection in draining lymph nodes and systemic dissemination to the spleen during acute infection. In the absence of IFNAR signaling, infected B cells accumulated to higher numbers, including an increased proportion of infected germinal center phenotype B cells, and this was accompanied by enhanced activation of T and B lymphocytes. Using two-photon microscopy, we further examined NK cell behavior within infected lymph nodes. NK cells were rapidly recruited to sites of infection but did not form stable clusters or prolonged contacts with infected cells. Nevertheless, NK cell depletion resulted in increased numbers of infected cells, indicating that NK cells contribute to the control of acute MHV68 infection despite the absence of detectable long-lasting interactions with infected cells. Together, our findings provide a single-cell view of acute gammaherpesvirus infection and innate immune control within lymph nodes in vivo. These data refine our understanding of how type I IFN responses and NK cells restrict early gammaherpesvirus spread and shape infection dynamics within lymphoid tissues. Author SummaryCertain viruses can remain in the body for life and cause little harm in healthy individuals. However, when the immune system is weakened, these infections can lead to cancer or other life-threatening diseases. To study human gammaherpesviruses within the living body, scientists often use a closely related mouse virus to understand how the immune system controls these infections. In this study, we tracked virus-infected cells within lymph nodes, important sites of the immune responses. Using a fluorescent virus together with advanced imaging techniques, we visualized infected cells directly in intact tissues. We found that type I interferons, a key component of the early antiviral defense, strongly limited the number of infected cells. Mice that could not respond to type I interferons developed substantially larger infections. We also investigated the role of natural killer cells, immune cells that provide rapid protection against viral infections. Although these cells quickly accumulated at sites of infection, they rarely formed prolonged contacts with infected cells. Together, our findings provide a detailed view of how innate immune defenses restrict gammaherpesvirus infection within lymph nodes. By revealing how early immune responses limit viral spread, this work improves our understanding of mechanisms that protect against severe herpesvirus-associated disease.

immunology↗

Hearing Lips and Seeing Voices After Fifty Years: A Large-Scale McGurk Illusion Dataset for Audiovisual Speech Research

Efficient face-to-face communication relies on the integration of auditory speech and visual articulatory signals. Over the past five decades, the McGurk illusion has been widely used as an index of audiovisual speech integration. However, substantial variabilities in susceptibility to the illusion across participants and speakers limit its reliability as a stable measure of audiovisual integration ability. Here, we introduce the McGurk illusion dataset (MID), which, to our knowledge, is the largest publicly available McGurk stimulus dataset to date. The MID comprises auditory (N = 400), visual (N = 400), and audiovisual (N = 640) speech stimuli generated from 80 Mandarin speakers and validated through behavioral judgments across 360,900 trials. Using this dataset, we characterized the acoustic and facial articulatory properties of McGurk stimuli, replicated substantial inter-participant and inter-speaker variabilities in illusion susceptibility, and revealed the associations between variations in McGurk illusion rate and the variations in unisensory perception, audiovisual correspondences, and speakers characteristics. Furthermore, the stimulus set enabled systematic comparisons of the reliability of different McGurk illusion-based indices of audiovisual speech integration. Overall, the MID not only provides a standardized resource for investigating audiovisual speech integration and its alterations across populations, but also supports research on speaker normalization, lip-reading, and speech perception.

neuroscience↗

Tracing the Evolutionary Origin of Interferon to Basal Chordates and Unveiling Its Antiviral Functionality in Jawless Vertebrates

Interferons (IFNs) are essential mediators of antiviral defense in vertebrates, having gradually replaced the RNA interference (RNAi) antiviral mechanism that predominates in invertebrates and plants. To date, IFNs have been identified exclusively in jawed vertebrates, leaving the origin of IFN-based antiviral mechanisms largely mysterious. In this study, by conducting a genome-wide screening of IFN homologs accross various species, we successfully identified seveal IFN homologs from agnatha and lancelet, but not other invertebrates. Notably, both agnatha and lancelet IFN homologs have ability to induce a set of interferon-stimulated genes (ISGs)-like genes, thus tracing the origin of IFN to basal chordate. Using VSV infected peripheral blood mononuclear cells (PBMCs) of Japanese lampreys, we found that lamprey IFNs have antiviral functionality by inducing the expression of hundreds of ISGs through interacting with a heterodimeric complex composed of CRFB7 and CRFB14. In addition to robustly mediating antiviral responses in monocytes, lamprey IFNs exert their effects on variable lymphocyte receptor B (VLRB)+ cells by remodeling the cytokine/chemokine networks to orchestrate antiviral innate and adaptive immunity. Furthermore, cross-species functional comparison of Dicer revealed that changes in residues essential for dsRNA processing occurred concurrently with the evolution of the IFN system. Collectively, these findings uncover the evolutionary origin of IFN and underscore its ancient roles in antiviral response and immune regulation, especially in the takeover of the RNAi antiviral mechanism during the early evolution of vertebrates. Significance StatementInterferons (IFNs) represent a hallmark of vertebrate antiviral immunity, yet their origin has remained elusive. Here, we reported bona fide IFN ligands and cognate receptors in both lamprey and lancelet, two key species placed at the transition from invertebrates to vertebrates. Using the VSV infection model, we further demonstrated the roles of lamprey IFN in antiviral defense and immune regulation. We also found that substitutions in residues essential for Dicer mediated dsRNA processing coincided with the emergence of the IFN system. Collectively, our findings provide key insights into the evolutionary origin of IFN-based immunity and its gradual replacement of RNAi as the dominant antiviral strategy in vertebrates.

evolutionary biology↗

Interference-Free Propagation: Achieving Reliable Signal Propagation in Cortical Networks with Areal-Specific Local Dynamics

In cortical networks, how to simultaneously achieve both reliable inter-areal signal propagation and areal-specific local dynamics remains largely unclear. In general, strong connections between areas enhance signal propagation, but blend timescales of area-specific neuronal activity, whereas weak connections have the opposite effect. Here we identify a novel dynamical regime termed "interference-free propagation" (IFP) that reconciles the two contrasting demands in the cortex. In the IFP regime, mean signals from upstream areas can propagate reliably, but fluctuations indicative of upstream areas timescales are filtered out. This result provides new insights into the operational regime of the cortex, leading to the coexistence of reliable signal propagation and the distinct property of local temporal integration of information in the cortical network.

neuroscience↗

Embryo-scale Visual Cell Sorting reveals a conserved transcriptomic signature of nucleolar size linked to proteostasis

Nucleoli, nuclear speckles and other compartments regulate transcription, RNA processing, and chromatin organization within the nucleus, yet the relationship of their morphology to developmental gene expression programs in vivo is poorly understood. Here, we develop a high-throughput Visual Cell Sorting (VCS) workflow for fixed cells and nuclei that combines antibody-based photoconversion; GPU-accelerated, real-time image analysis; and three-level single-cell combinatorial indexing RNA-seq (sci-RNA-seq3) to link nuclear compartment morphology to single-nucleus transcriptomes at embryo scale. We use VCS to analyze and sort over 1 million mouse embryo-derived nuclei by nucleolar, nuclear speckle, or nuclear size and construct a transcriptional atlas annotated with nuclear compartment phenotypes. Nuclear compartment size varies both between and within lineages and is shaped by proliferation and differentiation. In extracellular matrix protein-producing cell types such as fibroblasts, chondrocytes, and osteoblasts, nucleolar enlargement is uncoupled from cell cycle, and in erythroid cells exhibit a sharp nucleolar contraction preceding cell-cycle exit. We identify a 41-gene transcriptional signature whose expression tracks nucleolar size, enriched for ribosome biogenesis, mitochondrial metabolism, unfolded protein response, stress granule, and ubiquitin-proteasome pathway components. We used this nucleolar transcriptional signature to annotate mouse, zebrafish and human developmental atlases with nucleolar size information, revealing a conserved coupling between nucleolar activity and proteostasis programs. Our work establishes Visual Cell Sorting as a scalable platform for mapping image-based phenotypes to molecular programs; details the relationship between nuclear compartment phenotypes and development; and provides a transcriptional signature to estimate nucleolar size from existing single-cell datasets.

genomics↗

Prediction of Transcription Factor DNA Binding Affinity with High-Throughput Kd Measurements and Deep Learning

Transcription factors (TFs) regulate gene expression through specific interactions with genomic DNA. While TF binding motifs from public databases describe sequence preferences, quantifying genome-wide affinity (Kd) is highly desirable for a more accurate thermodynamic description. Here, we report ivtFOODIE (in vitro FOOtprinting with DeamInasE), an assay that leverages deaminase-mediated cytosine-to-uracil conversion to measure Kd values for a given TF across accessible genomic regions from human cells. By pre-training on TF binding sites from JASPAR and fine-tuning with our ivtFOODIE data from 46 TFs representing 13 different DNA-binding domains (DBDs), we developed Seq2Kd, a deep learning model capable of predicting a TFs absolute binding affinity on DNA sequences. Seq2Kd enables de novo motif discovery of [~]500 previously uncharacterized human TFs and reveals the effects of genetic variation both in TF-coding regions and DNA-binding sites on gene expression and disease susceptibility. By correlating predicted affinity changes with the sign and magnitude of expression quantitative trait locus (eQTL) effects, we stratified TFs into activator-like and repressor-like groups. Compared to clinically benign variants, pathogenic single-nucleotide variants (SNVs) within regulatory and protein-coding regions show significantly larger predicted shifts in Kd. We provide an interactive web portal, the ENcyclopedia of Transcription-factor Interactions with Regulatory Elements (ENTIRE), which integrates the Seq2Kd model with the ivtFOODIE dataset. This resource offers thermodynamic prediction for TF-DNA interactions for functional genomics and human disease.

biophysics↗

Reduction in Hepatic Phosphatidylcholine Biosynthesis Promotes MASH Through Copper Deficiency

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive liver disease for which the mechanisms linking lipid dysregulation to fibrosis remain poorly defined. Hepatic phosphatidylcholine (PC) content is reduced in MASH, but how this alteration drives disease progression is unclear. Here, we identify a role for copper (Cu) homeostasis as a downstream effector of impaired PC biosynthesis. Using single-nucleus RNA sequencing in complementary genetic and dietary mouse models, we found that reduced hepatic PC is associated with marked depletion of hepatic Cu and a concomitant increase in circulating Cu, indicating disrupted Cu distribution. Mechanistically, PC depletion impaired plasma membrane localization of the high-affinity Cu transporter CTR1 (SLC31A1) in hepatocytes, limiting Cu uptake. In human hepatic stellate cells, Cu promoted fibrogenic activation, whereas suppression of Cu import or pharmacologic inhibition of MAPK signaling attenuated fibronectin deposition. In vivo, liver-directed Cu supplementation restored hepatic Cu levels and reduced steatosis but failed to improve fibrosis. In contrast, pharmacologic Cu chelation with bathocuproinedisulfonic acid (BCS) reduced fibrosis without affecting inflammation. Together, these findings identify Cu redistribution as a consequence of impaired PC biosynthesis and implicate Cu-dependent signaling in stellate cell activation, fibrogenesis and MASH pathogenesis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/723926v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1c2bd52org.highwire.dtl.DTLVardef@1b8295org.highwire.dtl.DTLVardef@1a129dorg.highwire.dtl.DTLVardef@1bc2b87_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

Coordinated acetylcholine release and adaptation of neuronal representations in the retrosplenial cortex during contextual uncertainty

Accurate learning underpins optimal predictions and requires the brain to navigate uncertainty, identifying important information and distinguishing between expected and unexpected uncertainties. Theoretical models propose that the neuromodulator acetylcholine positively correlates with expected uncertainty, priming neuronal networks for learning. We tested this hypothesis by measuring acetylcholine release and neuronal representations in the retrosplenial cortex of mice whilst challenging them with expected and unexpected uncertainties of reward location. Acetylcholine release did not directly correlate with expected or unexpected uncertainty but instead increased with changes in expected uncertainty. In tandem, increased expected uncertainty shifted neuronal representations from a positional reference frame to focus on salient landmarks, such as reward location. Transitions in expected uncertainty also accelerated remapping of neuronal representations and behavioural adaptation when unexpected uncertainty was experienced. Thus, we demonstrate acetylcholine release in retrosplenial cortex discerns types of uncertainty and correlates with learning speed in uncertain environments.

neuroscience↗

Computational modeling of pro-inflammatory cytokine-enhanced blood coagulation

The interplay between inflammation and coagulation is a central driver of thrombotic risk across various diseases. While mathematical models of blood coagulation are well established, there remains a critical gap in quantitative frameworks that capture inflammation-induced hypercoagulability. In this study, we develop a mathematical model that explicitly simulates the interaction between pro-inflammatory cytokines and the coagulation cascade. The model incorporates key mechanisms, including: (i) upregulation of tissue factor (TF) by IL-1{beta}, IL-6, and TNF-; (ii) suppression of natural anticoagulants, namely antithrombin III (ATIII) and tissue factor pathway inhibitor (TFPI), by IL-6 and TNF-; and (iii) feedback amplification of proinflammatory cytokines by thrombin. By encoding the bidirectional feedback between inflammatory and coagulation pathways, the model captures essential features of inflammation-driven hypercoagulability and enables systematic quantification of how variability in inflammatory extent and duration results in heterogeneous thrombin generation (TG) dynamics. To evaluate its effectiveness, we integrate the model with TG assays and apply it to virtual patient cohorts representing four clinically distinct conditions: COVID-19, sickle cell disease (SCD), type 2 diabetes mellitus (T2DM) and Hemophilia A. Model simulations predict that disease-specific inflammatory environments induce distinct shifts in TG dynamics. In COVID-19 and T2DM, elevated cytokine levels lead to shortened lag times and increased thrombin peak, whereas in SCD, shortened lag times are accompanied by a reduced thrombin peak. These effects are strongly modulated by both cytokine concentration and duration of exposure. These results demonstrate that the proposed computational model augments conventional TG assays by mechanistically linking inflammatory signaling to disease-specific coagulation responses. Collectively, the proposed computational framework extends conventional TG assays by considering the interplay between inflammation and coagulation, thereby providing a potential tool for predicting disease progression and identifying disease-specific therapeutic targets to advance personalized management strategies in thrombo-inflammatory disorders.

biochemistry↗

Foxp4+ Mandibular Skeletal Stem Cells Orchestrate Bone/Tooth Development and Regeneration

The identity of stem/progenitor cells that drive mandible/tooth development and regeneration remains poorly understood. Here, we show that cranial neural crest-derived Foxp4+ mesenchymal cells condense to form Meckels cartilage, and simultaneously promote mandible development and tooth germ formation. In postnatal mandibles, Foxp4+ cells localize in the endosteum, periosteum and dental pulp, which undergo osteogenesis and odontogenesis under steady state, as well as chondrogenesis during fracture repair. Importantly, transplantation of embryonic or adult Foxp4+CD200+CD105- mandibular skeletal stem cells (mdSSCs) generate ectopic bone and tooth. In contrast, genetic ablation of Foxp4+ cells severely impairs mandible/tooth development and delays fracture healing. Mechanistically, we find that primary cilia critically regulate mdSSC maintenance and differentiation into bone and tooth. FOXP4+PDPN+CADM1+ mdSSCs also exist in adult human mandible, which generate ectopic bone and intact tooth upon transplantation into immunodeficient mice. Taken together, we identify Foxp4+ mdSSCs with potential therapeutic applications in regenerating mandibular bone and tooth.

cell biology↗

RVQ-Alpha: Bridging Single-Cell Transcriptomics and Large Language Models via Discrete Tokenization and Verifiable Reinforcement Learning

Single-cell RNA sequencing yields continuous expression profiles, whereas large language models operate over discrete autoregressive sequences, leaving no shared computational interface for language-model reasoning over cell states. Existing approaches either keep cellular information outside the LLM vocabulary, consume context per listed gene, or learn reconstruction codes without gene-level grounding. We introduce RVQ-Alpha, which systematically adapts four stages of LLM training (tokenization, supervised fine-tuning, reinforcement learning, and distillation) to single-cell analysis. Multi-codebook Residual Vector Quantization (RVQ) lexicalizes each profile into a compact, hierarchical cellular alphabet in the models native token stream, while a paired decoder reconstructs the corresponding expression profile. Evidence-First supervision grounds these symbols in named genes and expression-linked evidence; Fact-Aware RLVR then penalizes contradictory claims to support auditable reasoning. Task-specific RLVR yields strong experts, but a single Mixed policy underperforms them across all four task families. To recover specialist competence in a unified model, we adopt Multi-Teacher On-Policy Distillation (MOPD), which consolidates these experts into one All-in-One checkpoint without retaining a separate policy for each task. On the CAPSTONE benchmark, a four-task suite with explicit biological shifts and deterministic ontology-aware graders, the unified checkpoint improves over Mixed on all 12 metrics and remains within 0.005 of the task-routed specialist reference on every primary metric. Overall, RVQ-Alpha provides a unified pipeline for grounded, auditable multi-task single-cell analysis.

bioinformatics↗

Cell-type specific allelic dampening of sex-linked genes in sex chromosome aneuploidy

Common sex chromosome aneuploidies (SCAs) often present with cognitive and cardiovascular dysfunction in humans. To address SCA effects on gene expression and DNA methylation in relevant cell types, we differentiated neural precursor cells (NPCs) and cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs) with different numbers of sex chromosomes, including isogenic and independent lines. As expected, the expression of genes that escape X inactivation (escapees) mostly increases with the number of inactive X chromosomes (Xi). However, allelic analysis shows dampening of escapees specifically on the Xi in XXY compared to XX in both NPCs and CMs, revealing a novel type of dosage compensation in SCA. In contrast, Y-linked gene expression is higher in XXY versus XY NPCs, but the opposite is observed in CMs. This may explain the greater number of differentially expressed autosomal genes in NPCs versus CMs with an added Y chromosome, while effects of added X chromosomes are similar between cell types. Concordantly, changes in autosomal DNA methylation are mainly driven by the presence of a Y chromosome. These findings highlight the cell-type specificity of sex-linked and autosomal gene regulation in SCA conditions. HighlightsO_LISex chromosome aneuploidy induces cell-type specific changes in gene expression C_LIO_LIDampening of the inactive X chromosome in XXY alleviate X overexpression C_LIO_LIHigh Y-linked gene expression in XXY neuronal precursor cells but not cardiomyocytes C_LIO_LISex chromosome aneuploidy disrupts sex biases in autosomal gene expression C_LI

molecular biology↗

Generic versus personalized foot-ground contact models for predictive simulations of walking: Is personalization worth the effort?

PurposeQuantification of walking function, including joint motions, ground reactions, and joint loads, outside the lab is a growing research area. Because only joint motions can currently be measured outside the lab, researchers are utilizing tracking optimizations of walking to estimate associated ground reactions and inverse dynamic joint loads. However, foot-ground contact models used in such optimizations have been generic rather than personalized, which may limit the accuracy of estimated ground reactions and joint loads. This study compares the predictive capabilities of generic versus personalized foot-ground contact models. MethodsGeneric and personalized foot-ground contact models were evaluated in calibration and tracking optimizations performed using experimental walking data collected from three subjects in varying states of health. Foot-only calibration optimizations evaluated how well both models could reproduce experimental ground reaction and foot motion data while tracking both types of data simultaneously, while whole-body tracking optimizations evaluated how well both models could reproduce experimental ground reactions, joint motion, and joint load data while tracking only experimental joint motion data and achieving dynamic consistency. ResultsFor all three subjects and both types of optimizations, personalized foot-ground contact models reproduced experimental ground reaction, joint motion, and joint load data more accurately than generic foot-ground contact models. ConclusionPersonalized foot-ground contact models can improve the accuracy with which ground reactions and joint loads can be estimated via tracking optimizations of walking using only experimental motion data as inputs. Personalized models require little time and effort to calibrate using freely available software tools and should improve the accuracy of predictive simulations of walking as well.

bioengineering↗

Spikes meet Spins: Quantum-Native Neural Decoding for Ultra_Low-Latency Brain-Computer Interfaces

Brain - computer interfaces (BCIs) require rapid and accurate decoding of neural activity, yet conventional computing architectures face growing latency as neural recording scales. We demonstrate a quantum computing - enabled neural decoding approach using a physical 1000-qubit coherent photonic Ising machine, in which inference is performed through hardware energy relaxation rather than numerical computation. By mapping sparse neural spike patterns onto Ising Hamiltonians, our hardware-native Quantum Semi-Restricted Boltzmann Machine achieves up to 96.2% accuracy across public in vivo datasets spanning multiple species and modalities. We report hardware-verified median latencies of 0.075 ms-- a tenfold speedup over GPUs--with complexity-invariant scaling. These results establish quantum computing as a viable pathway toward ultra-low-latency neural decoding for future BCI systems.

neuroscience↗

VeloTrace Reconciles Divergent Velocity and Trajectory in Single-cell Transcriptomics with Deep Neural ODE

Cellular identity and fate transitions are governed by continuous molecular processes that form dynamic trajectories within a high-dimensional transcriptomic landscape. Existing methods attempt to model these dynamics from two complementary perspectives: trajectory inference and velocity modeling. Ideally, velocity and trajectory are dual aspects of transcriptomic dynamics where velocity is tangent to trajectory everywhere. This inherent connection between velocity and trajectory is currently absent in transcriptomic analysis. Splicing velocity are precision-limited to inadequately-sequenced genes, while trajectory inference prioritizes the modeling of global trends while omitting local dynamics. This divergence breaks the geometric continuity between local velocities and global trajectories, hindering the reliable interpretation of developmental dynamics. To reconcile trajectory inference and RNA velocity, we introduce VeloTrace, a framework that unifies them through Neural Ordinary Differential Equations (NeuralODEs). VeloTrace learns a continuous-time velocity field whose integral curves constitute the trajectory itself, while ensuring that velocities are tangent to integral paths everywhere. Leveraging a splicing quality score, VeloTrace incorporates high-quality splicing velocity as partial supervision for velocity orientation and grounding. During optimization, VeloTrace incorporates a Monte Carlo multi-time-frame supervision strategy to ensure coherence between local and global trajectorys and suppress sequencing-induced stochastic diffusion. Through refining the velocity field and cell-specific parameters for pseudo-time, expression, and velocity, VeloTrace reconstructs a smooth, local-and-global-coherent velocity-vector-guided flow in the transcriptomic latent space. This strategy ensures a complementary integration of velocity and trajectory, imputing the transcriptional kinetics for genes of insufficient strength, whose kinetics cannot be accurately portrayed by splicing velocity. In simulation benchmarks, VeloTrace captured the transcriptional dynamics of all expressed genes, even those with inadequate sequencing coverage, producing velocity directions that were most consistent with the true direction and every-where tangential across the entire process, outperforming state-of-the-art methods, including scVelo, UniTVelo, VeloVI and scTour. VeloTrace uniquely reconciles RNA velocity and trajectory inference, creating a velocity field where each cell can infer past and future transitions from its current state. Moreover, VeloTrace extends reliable velocity estimation to a broader set of genes. When applied to mouse neural stem cell differentiation data, it successfully recovers dynamics of driver genes for two developmental lineages, including those with low expression, shedding light on their regulatory roles during differentiation. This unified framework lays the foundation for more accurate modeling of gene regulation and cell fate decisions in complex biological systems.

bioinformatics↗

Chromosomal rearrangements 1 and sequence similarity drivepreferential allosyndetic introgression from a wild relative into wheat

Recombination in polyploid genomes is generally constrained to homologous or homoeologous chromosomes; however, how chromosomal rearrangements influence recombination between chromosomes remains unclear. Here, we demonstrate that large-scale chromosomal rearrangements in the wild relatives of wheat are associated with recombination involving non-homoeologous chromosomes or arms during alien gene introgression under conditions that permit homoeologous recombination mediated by ph1b. Using a wheat chromosome 6A monosomic-induced 6AS*6CL Robertsonian translocation combined with ph1b-mediated recombination, we generated 17 independent recombinants carrying a new stem rust resistance gene, Sr69, from Aegilops caudata chromosome arm 6CL. Unexpectedly, 94.1% (16 of 17) of recombinants resulted from exchanges with wheat group-7 chromosomes rather than with the homoeologous group-6 chromosome. Comparative sequence- and marker-based analyses identified a 67-Mb rearranged interval on Ae. caudata 6CL that corresponds to telomeric regions of the long arms of wheat group-7 chromosomes. Sequence similarity within this interval was quantitatively associated with recombination frequency, with higher similarity corresponding to more frequent translocations. Physical and optical mapping showed that recombination within the rearranged interval generated compensating 7A/6C, 7B/6C, and 7D/6C translocations, whereas recombination outside this region produced non-compensating 6A/6C exchanges. An independent case involving the powdery mildew resistance gene Pm7C showed a similar correspondence between a rearranged 7CL region and preferential introgression into wheat 7DS. Together, these results indicate that ph1b-mediated recombination involving structurally altered chromosomes is driven by local chromosomal structure and sequence similarity rather than strict homoeologous group identity. This provides a mechanistic basis for harnessing untapped beneficial genes from structurally rearranged alien genomes. Significance StatementAlien gene introgression is a powerful strategy for wheat improvement, typically relying on ph1b-mediated recombination between homoeologous chromosomes. The genomic basis and outcomes of introgression from structurally rearranged alien chromosomes remain unclear. Here, we show that ph1b-induced recombination can efficiently target wheat-allosyntenic blocks in rearranged alien genomes, preferentially transferring genes from structurally altered alien segments into their syntenic regions on wheat chromosomes of different homoeologous groups. Crossover formation is governed by extended sequence similarity within corresponding intervals rather than strict collinearity across entire homoeologous chromosomes. As many wild species exhibit extensive genome rearrangement, these findings and methodologies expand access to underexploited genetic diversity embedded within highly rearranged wild genomes for wheat improvement.

genetics↗