Biology subjects

Meng, G.

Publications and source records attributed to Meng, G..

At least 19 recordsLinked to original sources

bioRxiv2026

Defining cell type-specific diurnal gene expression in the mouse retina

The mammalian retina exhibits daily oscillations in gene expression that contribute to retinal physiology and visual function. However, the extent to which these temporal patterns differ among retinal cell types remains incompletely understood. We performed single-nucleus RNA sequencing in the mouse retina over the day and night, identifying rhythmic genes in the six major retinal cell types. Distinct diurnal gene expression patterns across photoreceptors, interneurons, retinal ganglion cells, and Muller glia correspond to their diverse functions across the light cycle. Even core circadian clock genes exhibited differences in paralog expression and rhythmicity across the retina. In contrast, dopamine signaling via the DRD4 receptor is highly rhythmic across most retinal cell types, suggesting dopamine signaling may be a key rhythmicity cue in the retina under diurnal conditions. This dataset highlights the complexity of daily transcriptional regulation in the retina and provides a resource to explore cell-type-specific diurnal rhythms.

neuroscience↗

bioRxiv2026

Overcoming segmentation bottlenecks in brain tissue for spatial proteomic inference at population scale

In spatial proteomics across large cohorts, downstream estimates from tens of thousands of images depend on accurate cell segmentation. Yet pretrained segmentation models struggle with morphologically complex cell bodies in human brain tissue, and how domain adaptation affects downstream discovery remains unclear. Here, we introduce SPInfer, a workflow for spatial proteomic inference developed using 5,832 manually annotated cell bodies from 120 immunofluorescence images of the human prefrontal cortex. After benchmarking eight segmentation methods spanning classical, convolutional, and foundation models, we adapted Cellpose-SAM, raising cell segmentation F1 from 0.37 to 0.84 and recovering cell compositions concordant with matched single-nucleus RNA-seq and spatial transcriptomics. Across 14,765 images from 69 postmortem donors, identical Alzheimer's disease pathology models found no significant associations after false discovery rate correction using zero-shot masks, versus four using fine-tuned masks; three linked higher OLIG2-positive fractions to greater neurofibrillary tangle and plaque burden. Using the fine-tuned masks, a graph attention network over nuclear neighborhoods classified four cell types without marker information, and differential expression analysis linked cell morphology to gene expression. This provides a pipeline for fine-tuning foundation models to segment complex tissues, enabling biological discovery in spatial proteomics at the population scale.

bioinformatics↗

bioRxiv2026

Chromatin states coordinate diurnal gene expression in the Drosophila retina

Daily biological rhythms enable organisms to anticipate and respond to predictable diurnal environmental changes. While the circadian clock maintains rhythms under constant conditions, it remains unclear what gates the time-of-day expression of genes that are rhythmic under light:dark cycles. In the retina, restricting biological processes to specific times of the day is crucial for homeostasis because disrupting these rhythms causes retinal degeneration. We show that in light-sensitive photoreceptor neurons of Drosophila, the circadian transcription factors only account for the timing of a minority of rhythmic genes. Instead, integrative analysis of the daily chromatin landscape and transcription factor footprints reveals that promoter, enhancer, or repressive signatures strongly correspond with phase. Further, genetic modulation of the repressive and promoter chromatin states altered gene expression in a phase-specific manner. Together, our data support a model where the genome is organized into discrete chromatin signatures that collaborate with transcription factors to restrict diurnal transcription to distinct phases of the day.

genomics↗

bioRxiv2026

SpatialClaw: A Memory-Augmented Autonomous Ecosystem for Spatial Omics Analysis

While the expansion of spatial omics has revolutionized our ability to dissect tissue architecture, the accumulation of incompatible computational methods has heavily fragmented end-to-end analysis, rendering complex workflows irreproducible. Generic conversational agents lack the domain-specific precision necessary to navigate the intricate biological pipelines. To overcome this, we present SpatialClaw, a memory-augmented autonomous ecosystem to unify spatial omics analysis under a single natural-language interaction. SpatialClaw integrates 30 specialized skills, spanning raw data preprocessing, spatial domain identification, deconvolution, spatially variable gene detection, cell-cell communication analysis, multi-sample and cross-modality integration. Distinct from existing agents, SpatialClaw introduces a graph-based persistent memory architecture that stores dataset metadata, analysis lineage, biological insights, and user preferences as versioned nodes and edges across three hierarchical layers (Session, Episodic, and Semantic), governed by a deterministic promotion policy. A Memory-Augmented Reasoning (MAR) Operator bridges the memory store and the main agent, synthesizing retrieved experiences into task-specific guidance for each query. In rigorous benchmarking spanning three memory-sensitive scenarios across 10 spatialomics skills, SpatialClaw outperforms both a standard large language model and the memory-only configuration. Furthermore, we demonstrate its robust biological utility by dissecting the complex tumor microenvironment of a 15-section human triple-negative breast cancer cohort. In merely three conversational turns and with zero direct scripting, SpatialClaw executes a comprehensive end-to-end workflow, yielding standardized output bundles. Ultimately, by synergizing comprehensive analytical tools with structured persistent memory, SpatialClaw elevates spatial omics from disjointed computational stitching to a fully traceable, reproducible, and self-improving discovery ecosystem. SpatialClaw is ready to use at https://github.com/ShangBioLab/SpatialClaw.

bioinformatics↗

bioRxiv2025

Broad epigenetic shifts in the aging Drosophila retina contribute to its altered rhythmic transcriptome.

Alterations in biological rhythms are a common feature of aging, and disruption of circadian rhythms can exacerbate age-associated pathologies. The retina is critical for detecting light for both vision and for transmitting time-of-day information to the brain, synchronizing rhythms throughout the body. Disruption of circadian rhythms by manipulating the molecular clock leads to premature retinal degeneration in flies and mice, and gene expression rhythms are disrupted in models of age-associated ocular disease. Despite this, it is unknown how or why the gene expression rhythms of the retina change with age. Here, we show that [~]70% of the Drosophila transcriptome is rhythmically expressed throughout the diurnal cycle, with [~]40% of genes showing altered rhythms with age. These transcriptome-wide changes in aging photoreceptors are accompanied by shifts in the rhythmic patterns of RNA Polymerase II (Pol II) occupancy, histone H3 lysine 4 (H3K4) methylation, and chromatin accessibility, without major changes in occupancy of the circadian clock transcription factors Clock (Clk) and Cycle (Cyc). Instead, aging decreases genome-wide levels of several different histone methyl marks including H3K4 methylation, whose relative levels across the day correlate with the phase of rhythmic gene expression. Moreover, individual knockdown of the three H3K4 methyltransferases in young photoreceptors results in massive disruptions to rhythmic gene expression that resemble those observed during aging. We conclude that there are broad epigenetic shifts in the aging retina, including decreased histone methylation, that contribute to changes in biological rhythms even in the presence of a robust molecular circadian clock.

molecular biology↗

bioRxiv2025

Chromatix: a differentiable, GPU-accelerated wave-optics library

Modern microscopy methods incorporate computational modeling as an integral part of the imaging process, either to solve inverse problems or optimize the optical system design itself. These methods often depend on differentiable optics simulations, yet no standardized framework exists--forcing computational optics researchers to repeatedly and independently implement simulations with limited reusability and performance. These common problems limit the potential impact of computational optics as a field. Here we present Chromatix: an open-source, GPU-accelerated, differentiable wave optics simulation library. Chromatix builds on JAX to democratize fast, parallelized simulation of diverse optical systems and expand the design space in computational optics. Chromatix standardizes a growing collection of optical elements and propagation methods allowing a broad range of applications, which we demonstrate here for snapshot microscopy, holography, and phase retrieval. We demonstrate speed improvements of 2-6x on a single GPU and up to 22x on 8 GPUs.

bioinformatics↗

bioRxiv2025

One-carbon metabolism enzyme Ahcy is a redox sensor that modulates gene expression to protect against light stress-induced retinal degeneration

One-carbon metabolism influences gene expression by providing methyl units for DNA, RNA, and histone methylation. Robust methylation requires rapid hydrolysis of the methylation by-product S-adenosylhomocysteine (SAH) by S-adenosylhomocysteinase (Ahcy). Here, we show Ahcy is a redox-sensitive enzyme that is inhibited by oxidation of a conserved cysteine, C195, in vitro and in vivo. Transient oxidation of Ahcy is neuroprotective in a Drosophila light stress model where it results in rapid gene expression changes and protects against retinal degeneration. Thus, redox sensing by the one-carbon metabolic enzyme Ahcy enables rapid changes in gene expression in response to changes in redox homeostasis.

biochemistry↗

bioRxiv2024

Telomere-to-Telomere Genome Assembly Uncovers Wolbachia-Driven Sex-Specific Demography and Challenges Fisher's Principle in a Sawfly

Wolbachia, a widespread endosymbiotic bacterium, can reshape the evolutionary fates of its insect hosts by distorting reproduction and altering population dynamics. Despite extensive laboratory research, its long-term effects on host evolution in nature remain poorly understood, particularly regarding genetic mechanisms underlying changes in sex determination and reproduction. Here, we report the first telomere-to-telomere (T2T) genome assembly of the sawfly Analcellicampa danfengensis and the complete genome of it symbiotic Wolbachia. Comparative population genomics of six closely related Analcellicampa species revealed that Wolbachia-infected populations experience marked changes in sex-specific demography. While uninfected species maintain balanced genetic features between males and females, infected species show a persistent reduction in male effective population size alongside a stable or even growing female population, ultimately driving males toward extinction. Genomic scans identified positively selected genes associated with reproductive functions, sensory perception, neural development, and longevity, suggesting that Wolbachia manipulates critical host biological pathways to promote its transmission. These findings provide direct genomic evidence that Wolbachia acts as a powerful evolutionary force, reshaping host genomes in a way that disrupts Fishers principle, ultimately driving female-biased demography and the extinction of males at evolutionary timescales. This work provides deeper insights into host- endosymbiont coevolution and has important implications for evolutionary theory and pest management strategies.

evolutionary biology↗

bioRxiv2024

Interleukin-1 prevents SARS-CoV-2-induced membrane fusion to restrict viral transmission via induction of actin bundles

Innate immune responses triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection play pivotal roles in the pathogenesis of COVID-19, while host factors including pro-inflammatory cytokines are critical for viral containment. By utilizing quantitative and qualitative models, we discovered that soluble factors secreted by human monocytes potently inhibit SARS-CoV-2-induced cell-cell fusion in viral-infected cells. Through cytokine screening, we identified that interleukin-1{beta} (IL-1{beta}), a key mediator of inflammation, inhibits syncytia formation mediated by various SARS-CoV-2 strains. Mechanistically, IL-1{beta} activates RhoA/ROCK signaling through a non-canonical IL-1 receptor-dependent pathway, which drives the enrichment of actin bundles at the cell-cell junctions, thus prevents syncytia formation. Notably, in vivo infection experiments in mice confirms that IL-1{beta} significantly restricted SARS-CoV-2 spreading in the lung epithelia. Together, by revealing the function and underlying mechanism of IL-1{beta} on SARS-CoV-2-induced cell-cell fusion, our study highlights an unprecedented antiviral function for cytokines during viral infection.

immunology↗

bioRxiv2023

Computational divergence analysis reveals the existence of regulatory degeneration and supports HDAC1 as a potential drug target for Alzheimer's disease

Epigenetic dysregulation has been widely reported in patients of Alzheimers disease (AD) and epigenetic drugs are gaining particular interest as a potential candidate therapy target. However, it is less clear how epigenetic dysregulation contributes to AD development. In this work, we performed regulatory divergence analysis using large-scale AD brain RNA-seq data and reported a widespread existence of regulatory degeneration among AD patients. It seems that transcription factor (TF)-mediated regulations get weakened or lost during AD development, resulting in disruption of normal neuronal function, especially including protein degradation, neuroinflammation, mitochondria and synaptic dysfunction. The regulatory degeneration burden (RDB) is well correlated with the detrimental clinical manifestations of AD patients. Studies of epigenetic marks, including histone modification, open chromatin accessibility and three TF binding sites supported the existence of regulatory degeneration. It suggested that epigenetic dysregulation contributed to regulatory degeneration, which also explained the consequence of epigenetic dysregulation. Among the epigenetic regulators, HDAC1 was proposed as a potential participator in such a process. Overall, our computational analysis suggested a novel causal mechanism of AD development and proposed HDAC1 as a drug target to treat AD.

systems biology↗

bioRxiv2023

imply: improving cell-type deconvolution accuracy using personalized reference profiles

Real-world clinical samples are often admixtures of signal mosaics from multiple pure cell types. Using computational tools, bulk transcriptomics can be deconvoluted to solve for the abundance of constituent cell types. However, existing deconvolution methods are conditioned on the assumption that the whole study population is served by a single reference panel, which ignores person-to-person heterogeneity. Here we present imply, a novel algorithm to deconvolute cell type proportions using personalized reference panels. imply can borrow information across repeatedly measured samples for each subject, and obtain precise cell type proportion estimations. Simulation studies demonstrate reduced bias in cell type abundance estimation compared with existing methods. Real data analyses on large longitudinal consortia show more realistic deconvolution results that align with biological facts. Our results suggest that disparities in cell type proportions are associated with several disease phenotypes in type 1 diabetes and Parkin-sons disease. Our proposed tool imply is available through the R/Bioconductor package ISLET at https://bioconductor.org/packages/ISLET/.

bioinformatics↗

bioRxiv2023

African Swine Fever Virus major capsid p72 Trimers function as a pH sensor during uncoating process of virus endocytosis

African swine fever virus (ASFV) belongs to nucleocytoplasmic large DNA viruses (NCLDVs), the only member of Asfarviridae. So far, it is revealed that the ASFV uncoating is a pH-dependent process undergone in late endosomes. But, the research on how pH affects capsid stability is limited, and which protein plays an essential role in pH sensing remains unknown. In this study, we identified the main component of the ASFV capsid -- major capsid protein p72, as a pH sensitive residue abundance protein, and it is speculated that the conformational change of the p72 trimer is possibly responsible for the ASFV uncoating process. To test this speculation, we obtained recombinant p72 trimers, treated with the acidic environment that simulated endosomes and displayed structural analysis. The results showed that the p72 trimer depolymerized at low pH. The depolymerization of trimers rationally explains the disassembly mechanism of the ASFV icosahedral capsid in endosomes.

microbiology↗

bioRxiv2023

Myosin inhibitor reverses hypertrophic cardiomyopathy in pediatric iPSC-cardiomyocytes to mirror variant correction

Hypertrophic cardiomyopathy (HCM) is mainly caused by sarcomere gene variants in MYH7 and MYBPC3. Targeted drugs like myosin ATPase inhibitors have shown efficacy in adult HCM but have not been evaluated in children. We generated iPSC-cardiomyocytes (CMs) from four children with HCM harboring variants in MYH7 (V606M; R453C) or MYBPC3 (G148R; P955fs and TNNI3_A157P), variant-corrected controls, and a healthy individual. All CMs showed hypertrophy and sarcomere disorganization. All 3 single variant CMs showed higher contractility, slower relaxation, higher calcium transients and higher ATPase activity. Only MYH7 variant CMs showed stronger myosin-actinin binding. Targeted myosin ATPase inhibitor showed complete rescue of the phenotype in affected CMs and in cardiac Biowires to mirror isogenic controls. The response was stronger compared to verapamil or metoprolol, highlighting the need for clinical trials of myosin targeted therapy in pediatric HCM patients. The phenotype and response to drug therapy are influenced by the underlying genotype.

genetics↗

bioRxiv2023

Mitochondrial genome evolution in the Diprionidae: Major gene rearrangement in the basal Hymenoptera

In comparison to other non-parasitic basal lineages, Apocrita have consistently demonstrated a greatly accelerated rate of gene rearrangement. A number of mechanisms or correlates have been proposed for this observation, such as oxidative stress tolerated by exposure to the host immune system might lead to a high proportion of rearranged mt-genomes. Our studies reveal that gene rearrangements involving the protein-coding gene are present in the basal Hymenoptera lineage based on enriched sampling. We speculate the processes of diversification of rearrangements in the vicinity of nad2 involved tRNAs and NCRs by producing the chronogram of Diprionids. Furthermore, we investigated the relationship between rearranged genes and their nucleotide sequences. In conclusion, we demonstrate the great potential of gene order and associated sequence features as phylogenetic markers in the study of Hymenoptera evolution, offering a new perspective on studying organisms that undergo frequent gene rearrangements.

evolutionary biology↗

bioRxiv2023

The complete chloroplast genome sequence of Akebia trifoliata and a comparative analysis within the Ranales clade

The complete nucleotide sequence of the Akebia trifoliata chloroplast (cp) genome was reported and characterized in this study. The cp genome is a closed circular molecule of 157 949 bp, composed of a pair of IR regions of 26 149 bp, one LSC region of 86 595 bp, and one SSC region of 19 056 bp. The GC contents of the LSC, SSC, and IR regions, and the whole cp genome are 37.11%, 33.62%, 43.08% and 38.66%, respectively. The cp genome contains 130 predicted functional genes, including 85 PCGs of 79 107 bp, 37 tRNA and 8 rRNA genes of 11 851 bp. 168 SSRs and 23 long repeats were identified in the cp genome. The results revealed that 21 891 codons characterize the coding capacity of 85 protein-coding genes in Akebia trifoliata, 10.84% and 1.20% of the codons coded for leucine and cysteine respectively. The usage of the start codon exhibited no bias in the A. trifoliata cp genome. Phylogenetic analysis suggest that A. trifoliata is most closely related to S. japonica, which then formed a cluster with N. dormestica and M. saniculifolia to form subgroup of Ranunculales. Our study provides information on mangrove plant species in coastal intertidal zones.

plant biology↗

bioRxiv2021

Nucleocapsid 203 mutations enhance SARS-CoV-2 immune evasion

Previous work indicated that the nucleocapsid 203 mutation increase the virulence and transmission of the SARS-CoV-2 Alpha variant. However, Delta later outcompeted Alpha and other lineages, promoting a new wave of infections. Delta also possesses a nucleocapsid 203 mutation, R203M. Large-scale epidemiological analyses suggest a synergistic effect of the 203 mutation and the spike L452R mutation, associated with Delta expansion. Viral competition experiments demonstrate the synergistic effect in fitness and infectivity. More importantly, we found that the combination of R203M and L452R brings in a 3.2-fold decrease in neutralizing titers to the neutralizing serum relative to L452R-only virus. R203M/L452R show an increased fitness after the initiation of global vaccination programmes, possibly associated with the enhanced immune evasion. Another rapidly emerging variant Omicron also bears the 203 mutation. Thus, we proposed that nucleocapsid mutations play an essential role for the rise and predominance of variants in concern.

microbiology↗

bioRxiv2021

A Useful Guide to Lectin Binding: Machine-Learning Directed Annotation of 57 Unique Lectin Specificities

Glycans are critical to every facet of biology and medicine, from viral infections to embryogenesis. Tools to study glycans are rapidly evolving, however the majority of our knowledge is deeply dependent on binding by glycan binding proteins (e.g., lectins). The specificities of lectins, which are often naturally isolated proteins, have not been well- defined, making it difficult to leverage their full potential for glycan analysis. Herein, we use glycan microarray analysis of 116 commercially available lectins, including different preparations of the same lectin, to extract the specific glycan features required for lectin binding. Data was obtained using the Consortium for Functional Glycomics microarray (CFG v5.0) containing 611 glycans. We use a combination of machine learning algorithms to define lectin specificity, mapping inputs (glycan sequences) to outputs (lectin-glycan binding) for a large-scale evaluation of lectin-glycan binding behaviours. Our motif analysis was performed by integrating 68 manually defined glycan features with systematic probing of computational rules for significant binding motifs using mono- and disaccharides- and linkages. Using a combination of machine learning and manual annotation of the data, we created a detailed interpretation of glycan-binding specificity for 57 unique lectins, categorized by their major binding motifs: mannose, complex-type N-glycan, O-glycan, fucose, sialic acid and sulfate, GlcNAc and chitin, Gal and LacNAc, and GalNAc. Our work provides fresh insights into the complex binding features of commercially available lectins in current use, providing a critical guide to these important reagents.

biochemistry↗

bioRxiv2021

Nucleocapsid mutation R203K/G204R increases the infectivity, fitness and virulence of SARS-CoV-2

In addition to the mutations on the spike protein (S), co-occurring mutations on nucleocapsid (N) protein are also emerging in SARS-CoV-2 world widely. Mutations R203K/G204R on N, carried by high transmissibility SARS-CoV-2 lineages including B.1.1.7 and P.1, has a rapid spread in the pandemic during the past year. In this study, we performed comprehensive population genomic analyses and virology experiment concerning on the evolution, causation and virology consequence of R203K/G204R mutations. The global incidence frequency (IF) of 203K/204R has rose up from nearly zero to 76% to date with a shrinking from August to November in 2020 but bounced later. Our results show that the emergence of B.1.1.7 is associated with the second growth of R203K/G204R mutants. We identified positive selection evidences that support the adaptiveness of 203K/204R variants. The R203K/G204R mutant virus was created and compared with the native virus. The virus competition experiments show that 203K/204R variants possess a replication advantage over the preceding R203/G204 variants, possibly in relation to the ribonucleocapsid (RNP) assemble during the virus replication. Moreover, the 203K/204R virus increased the infectivity in a human lung cell line and induced an enhanced damage to blood vessel of infected hamsters lungs. In consistence, we observed a positive association between the increased severity of COVID-19 and the IF of 203K/204R from in silicon analysis of global clinical and epidemic data. In combination with the informatics and virology experiment, our work suggested the contribution of 203K/204R to the increased transmission and virulence of the SARS-CoV-2. In addition to mutations on the S protein, the mutations on the N protein are also important to virus spread during the pandemic.

evolutionary biology↗