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Biology subjects

Tan, Q.

Publications and source records attributed to Tan, Q..

At least 19 recordsLinked to original sources

A virus co-opts vector's m⁶A machinery for adaptive compensation

Insect vectors harbor diverse viruses that threaten human health and agricultural production, yet the genetic basis of mutualistic virus-vector interactions remain elusive. This underscores a long-standing paradox in pest management: viruses that cause destructive diseases also facilitate vector adaptation in ways that benefit both parties. Here we show that the globally devastating tomato yellow leaf curl virus (TYLCV) acts as a Cooperative Partner, co-opting its vector's m6A epitranscriptomic machinery to offset the reproductive fitness costs of neonicotinoid resistance in the whitefly. In resistant vectors, TYLCV infection alleviates reproductive deficits via the m6A-dependent pathway, where the methyltransferase METTL14 and demethylase ALKBH4 coordinately stabilize vitellogenin (Vg) transcripts to boost female fecundity. Mechanistically, the viral C2 and CP proteins directly interact with METTL14 and ALKBH4, respectively, remodeling their RNA binding affinity to facilitate mA modification on Vg. Disrupting either of these viral-vector protein interactions restores a reproductive cost phenotype in viruliferous resistant vectors, offering novel targets for sustainable pest control. Our findings uncover a fundamental role of epigenetic marks in adaptive trait, reshaping beneficial virus-vector relationships and providing new insights for innovative public health and crop protection strategies to address global challenges.

microbiology↗

Assessing Microcirculation Impairment in Ischemic Stroke Mice Using Arteriovenous Co-fluctuation Analysis

Accurate assessment of cerebral hemodynamics impairment traditionally relies on arterial metrics, yet often overlooks venous drainage and arteriovenous dynamics, thereby limiting the evaluation of ischemia-induced microvascular dysfunction. To address this limitation, we implemented a signal-averaging framework, combined with co-fluctuation analysis, to extract predominantly arterial and venous hemodynamic signals and construct a dynamic arteriovenous co-fluctuation index that quantifies frame-by-frame coordination between arterial inflow and venous outflow activity. This time-resolved index enables spatial characterization of large-scale cortical arteriovenous coordination beyond conventional static correlation-based analyses. Comparative analyses between healthy controls and acute ischemic stroke mice demonstrated that the arteriovenous co-fluctuation index sensitively detects disruption of vascular coordination, revealing a slower state transition that occurs alongside distinct temporal abnormalities and regional heterogeneity between ischemic core and penumbral regions. These findings underscore the utility of arteriovenous coordination as a sensitive indicator of microcirculatory dysfunction, offering a practical analytical tool for assessing stroke-induced microvascular impairment.

neuroscience↗

Preconception e-nicotine impairs airway development and progenitor proliferation across generations in Drosophila Melanogaster

Electronic nicotine delivery devices are increasingly used worldwide, raising concern about the potential effects of nicotine exposure during fetal and early postnatal development. However, evidence regarding the effects of vaping during pregnancy remains limited, and the consequences of exposure before conception are largely unknown. Here, we investigated whether maternal nicotine vaping prior to conception alters airway development using the fruit fly Drosophila melanogaster. Offspring of nicotine-exposed mothers exhibited abnormal airway architecture, epithelial remodelling, and impaired terminal branching. These defects were accompanied by reduced proliferation of airway progenitor cells without increased apoptosis, resulting in decreased hypoxia tolerance, altered activity patterns, and reduced lifespan. Transcriptomic and functional analyses revealed suppression of innate immune signalling mediated by nuclear factor kappa-B (NF-{kappa}B). Notably, knockdown of its regulator Relish reproduced key phenotypes. Developmental abnormalities persisted across generations, with their severity progressively declining. Together, these findings identify maternal preconception nicotine exposure as a previously unrecognized determinant of airway development and provide insight into early origins of chronic airway disease. TeaserPreconception e-nicotine exposure shapes airway development, structural and physiological abnormalities across generations in Drosophila.

Developmental Biology↗

A horizontally transferred fungal deubiquitinase facilitates insecticides resistance in whitefly

Horizontal gene transfer (HGT) has enabled insects to acquire novel genetic material that can fuel adaptation to environmental change. However, the role of HGT in the evolution of insecticide resistance remains poorly characterised. Here, we identify BtUCH19, a fungal gene that has integrated into the genome of the global pest Bemisia tabaci and functions as a deubiquitinating enzyme (DUB). We show that compared to endogenous DUB, BtUCH19 specifically removes K63-linked ubiquitin chains from a cytochrome P450, CYP4C64, thereby stabilizing this key detoxification enzyme in vivo. Sustained CYP4C64 abundance enhances metabolic detoxification of two commonly used insecticides thiamethoxam (TMX) and clothianidin (CLO) to their low-toxicity products TMX-Urea and CLO-Urea. Consequently, BtUCH19 drives insecticide resistance through a novel "HGT-PTM-Metab" axis. Our work reveals the instrumental role of a HGT in orchestrating ubiquitin-proteasome system (UPS)-mediated protein level regulation of a key detoxification pathway. These findings offer new insights into the intricate mechanisms underlying co-evolutionary biology, and provide a new molecular target for Integrated Pest Management (IPM).

zoology↗

DOMINO: Learning Domain Co-occurrence for Multidomain Protein Design

Multidomain proteins arise through the reuse and recombination of structural domains, yet natural architectures represent a sparse, structured sample of the possible domain-combination space. Here, we introduce DOMINO, a two-stage framework that learns domain co-occurrence from TED-annotated multidomain proteins and uses the learned patterns to generate new multidomain sequences. DOMIN, a contrastive retrieval model, embeds domains into a latent compatibility space and retrieves candidate partners for a query domain from a TED-derived domain pool, including pairings not observed in the TED-derived co-occurrence set. DOMO, a conditional autoregressive sequence model, converts each retrieved domain pair into a full-length protein sequence by jointly generating the specified domain regions and the non-domain sequence context between and around them. DOMIN recovers hierarchical patterns of natural domain co-occurrence and expands the observed CATH homologous-superfamily co-occurrence network with candidate novel pairings. DOMO realizes both held-out natural pairs and DOMIN-retrieved pairs as proteins with high domain recovery and high AlphaFold-predicted structural confidence. Applied at scale, DOMINO generated 5 million retrieval-derived multidomain proteins, with sampled designs showing recovery of the specified domains, diverse CATH annotations, and sequence novelty relative to UniRef100. Together, these results support domain co-occurrence as a predictive design prior and demonstrate a scalable strategy for exploring multidomain protein architectures through new combinations of existing structural modules.

bioinformatics↗

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

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

microbiology↗

Sex differences in neural circuits driving binge drinking: A female-specific role for an amygdalo-striatal pathway

BackgroundRates of binge drinking have converged significantly between the sexes over recent decades, driven by increased rates of alcohol misuse in women. However, understanding of fundamental circuitry and neurobiology driving alcohol use in females, or how this may differ from male subjects remains underexplored. MethodsWe quantified c-Fos expression across 40 brain regions in alcohol naive, alcohol anticipating and binge drinking male and female mice. In vivo fiber photometry examined sex differences in basolateral amygdala (BLA) activity changes to alcohol intake. Chemogenetic BLA inhibition investigated a functional role in binge drinking. We then assessed sex differences in BLA efferent projection activation following binge drinking. Finally, we functionally interrogated the BLA to nucleus accumbens core (AcbC) projection in binge drinking. ResultsBinge drinking reduced network modularity (number of communities with similar activation patterns) in both sexes relative to alcohol naive and anticipating same-sex counterparts. Female binge drinking mice had increased BLA c-Fos expression compared to female naive and male binge drinking counterparts. In vivo fiber photometry revealed greater and more prolonged BLA responsivity at the onset of alcohol intake in females. Global BLA inhibition reduced reward intake in both sexes. However, the BLA to AcbC projection was preferentially activated in female binge drinking mice, and inhibition of this pathway reduced binge alcohol intake exclusively in females. ConclusionsWe identified sex differences in the neural circuits engaged in binge drinking, highlighting the BLA to AcbC projection may in part underpin sex differences in alcohol misuse. This provides further evidence of distinct neurobiological drivers of alcohol-related behaviors between the sexes.

neuroscience↗

Refining bias correction in genome-wide association analyses of case-control studies

Genome-wide association studies are vulnerable to confounding factors. This study provides evidence-based guidance for minimizing bias associated with genetic relatedness, SNP-specific non-additive allelic interactions, predisposed genotypes among controls, and multi-allelic polymorphism in case-control studies. The analyses demonstrated that genetic similarity within case or control groups introduces experimental bias, whereas genetic relatedness across case-control samples reduces this bias. These findings establish a general framework that can filter genetically related sub-communities or paired samples, whilst preserving maximal statistical power with minimal false-positive rates. Moreover, the skewed odds ratios resulting from predisposed genotypes among controls underscored the importance of age-related filtering to minimize this confounding effect. To ensure accurate genetic estimates, such as polygenic risk scores, the identification of SNP-specific allelic interaction models was also emphasized in case-control studies, contingent on normalization for within-population differences in genotype frequencies. Here, we introduce the Allelic-effect aware Case-Control GWAS (AlleliC-GWAS) tool for identifying SNP-specific allelic effects on binary traits. Finally, we recommend a strategy to accurately capture genetic effects at multi-allelic genomic positions.

bioinformatics↗

DAPL1 deficiency impairs autophagy in retinal pigment epithelium to drive age-dependent retinal pathologies

Age-related retinopathy, primarily comprising age-related macular degeneration (AMD), is a major cause of irreversible blindness in the elderly population worldwide. Although its precise mechanisms remain incompletely understood, autophagy deficiency in retinal pigment epithelium (RPE) cells has been associated with AMD in patients; however, the regulatory pathways involved are not fully elucidated. In this study, we report that deficiency in the Dapl1 gene inhibits RPE cell autophagy and leads to age-dependent retinal pathologies in mice. Specifically, 18-month-old Dapl1-/- mice manifest age-related retinal dysfunction and structural abnormities, including increased retinal stress, photoreceptor/RPE cell damage, lipid aggregates and microglial activation. Furthermore, we demonstrate that autophagy is impaired in the RPE cells of Dapl1-/- mice, while overexpression of DAPL1 in RPE cells enhances autophagy activity. Mechanistically, we elucidate that DAPL1 suppresses the expression of E2F1 and c-MYC, which consequently downregulates mTOR and upregulates ATG16 and Beclin1 expression via DAPK1 in RPE cells, thereby promoting autophagy. Taken together, our findings demonstrate that DAPL1 acts as a novel regulator of autophagy in RPE cells, and its deficiency increases susceptibility to age-dependent retinal pathologies in mice.

molecular biology↗

Capicua refines mossy fiber-CA3 axon targeting in the late postnatal hippocampus

Proper brain wiring relies on the precise distribution of axonal projections to specific subcellular domains of their target neurons. These spatially confined connections establish the anatomical foundation for neural circuit assembly. The mossy fiber (MF)-CA3 pathway in the hippocampus is an excellent system to study the mechanisms underlying lamina-specific connectivity. In rodents, MF projections develop postnatally and reach their mature configuration by the end of the second postnatal week. MF axons synapse on the proximal segments of the dendrites but avoid the somas of CA3 pyramidal neurons. As dentate gyrus granule neurons are continuously generated and integrated into the existing hippocampal circuit throughout the postnatal period and adulthood, the mechanisms that guide MF axons to achieve lamina-specific targeting of these later-born granule neurons remain unclear. Here, we show that deletion of the neurodevelopmental disorder-associated protein capicua (CIC) results in abnormal MF targeting in the mouse hippocampus. Notably, this defect emerges after the second postnatal week and persists into adulthood, distinguishing it from classical MF guidance defects, which typically manifest during the first postnatal week. We also demonstrate that this miswiring is due to CIC loss in dentate gyrus granule neurons rather than CA3 pyramidal neurons. Single-nucleus transcriptomics and trajectory analysis reveal a loss of a mature granule neuron subtype and dysregulation of axon guidance genes that are normally downregulated as granule neurons mature. Our findings uncover a previously unrecognized role for CIC in hippocampus development and offer insights into the regulation of lamina-specific MF connectivity in the postnatal brain.

neuroscience↗

Unlocking TAS2R14 activation through intricate multi-ligand binding networks

Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1-3. In addition, TAS2R14 has broad expression in non-gustatory tissues, suggesting its important roles in selective physiological processes and therapeutic potential4. Here, we present cryo-electron microcopy structures of TAS2R14 in complex with flufenamic acid and aristolochic acid, coupling with G protein subtypes gustducin and Gi. Distinct from most known GPCRs, agonists of TAS2R14 bind to multiple intracellular pockets. We highlight the cholesterol molecules occupying an upper transmembrane site, typically the orthosteric pocket in other GPCRs, also binding in the entrance to an intracellular agonist binding pocket, suggesting an endogenous modulatory function5. The structural and mutagenesis analysis illuminate the receptors broad-spectrum ligand recognition and activation via intricate multiple ligand-binding sites. Furthermore, we unveil the structural configuration of gustducin and its interaction with TAS2R14, as well as the coupling mode of Gi1. This investigation should be instrumental in advancing our knowledge of the mechanisms underlying bitter taste recognition and response, with broader relevance to sensory biology and pharmacology.

biophysics↗

Spatiotemporal transcriptomic profiling reveals the dynamic immunological landscape of alveolar echinococcosis

Alveolar echinococcosis (AE) is caused by the invasive growth of the metacestodes of Echinococcus multilocularis (E. multilocularis). The early diagnosis, management, and treatment of AE remains challenging. Herein, we integrated bulk RNA-seq, scRNA-seq, and ST technologies to reveal the immune characteristics both spatially and chronologically in E. multilocularis infected mouse liver. An unprecedented high-resolution spatial atlas of the E. multilocularis infection foci was obtained, revealing the pivotal role of neutrophils, Spp1+ monocyte-derived macrophages (MoMFs), and fibroblasts in AE progression. We observed continuous recruitment of neutrophils and macrophages into the infected tissues, indicating prolonged immune stimulation by the growing metacestodes. However, their spatial distribution patterns and functions changed during the infection cause. At the early infection stage, Il1bhi neutrophils aggregated in the lesion displayed the highest pattern-recognition receptor activity and may kill the metacestodes through NETosis, but their death in the infection foci might also trigger immune suppression. Meanwhile, Spp1+ MoMFs attached to the protoscoleces to clear the infection. At the late infection stage, the neutrophils failed to infiltrate into the lesion although their continuous recruitment into the infected liver. Even though the Spp1+ MoMFs enclosing the microcysts of E. multilocularis may retain their pathogen-killing ability, they may also promote fibrosis and angiogenesis through interaction with fibroblasts. The pro- and anti-inflammatory phenotype balance of these immune cells may be associated with the transition of parasite control strategy from "active killing" to "negative segregation" by the host. Our findings identify key molecular traits involved in AE development, which may benefit the treatment of echinococcosis.

immunology↗

Learning of the same task subserved by substantially different mechanisms between patients with Body Dysmorphic Disorder and healthy individuals

It is generally believed that learning of a perceptual task involving low-level neuronal mechanisms is similar between individuals. However, it is unclear whether this assumption also applies to individuals with psychiatric disorders that are known to have altered brain activation during visual processing. We investigated this question in patients with body dysmorphic disorder (BDD), a psychiatric disorder characterized by distressing or impairing preoccupation with nonexistent or slight defects in ones physical appearance, and in healthy controls. Participants completed six training sessions on separate days on a visual detection task for human faces with low spatial frequency (LSF) components. Brain activation during task performance was measured with functional magnetic resonance imaging (fMRI) on separate days prior to and after training. The behavioral results showed that both groups of participants improved on the visual detection task to a similar extent through training. Despite this similarity in behavioral improvement, neuronal changes in the Fusiform Face Area (FFA), a core cortical region involved in face processing, with training were substantially different between groups. First, activation in the right FFA for LSF faces relative to High Spatial Frequency (HSF) faces that were used as an untrained control increased after training in BDD patients but decreased in controls. Second, resting state functional connectivity between left and right FFAs decreased after training in BDD patients but increased in controls. Contrary to the assumption that learning of a perceptual task is subserved by the same neuronal mechanisms across individuals, our results indicate that the neuronal mechanisms involved in learning of a face detection task differ fundamentally between patients with BDD and healthy individuals. The involvement of different neuronal mechanisms for learning of even simple perceptual tasks in patients with BDD might reflect the brains adaptations to altered functions imposed by the psychiatric disorder.

neuroscience↗

Geometric-relationship specific transfer in visual perceptual learning

Visual perceptual learning (VPL) is defined as long-term improvement on a visual task as a result of visual experience. In many cases, the improvement is highly specific to the location where the target is presented, which refers to location specificity. In the current study, we investigated the effect of a geometrical relationship between the trained location and an untrained location on transfer of VPL. We found that significant transfer occurs either diagonally or along a line passing the fixation point. This indicates that whether location specificity or location transfer occurs at least partially depends on the geometrical relationship between trained location and an untrained location.

neuroscience↗

Differential effects of MATR3 variants on its cryptic splicing repression function

MATR3 is an RNA-binding protein implicated in neurodegenerative and neurodevelopmental diseases. However, little is known regarding the role of MATR3 in cryptic splicing within the context of functional genes and how disease-associated variants impact this function. We show that loss of MATR3 leads to cryptic exon inclusion in many transcripts. We reveal that ALS-linked S85C pathogenic variant reduces MATR3 solubility but does not impair RNA binding. In parallel, we report a novel neurodevelopmental disease-associated M548T variant, located in the RRM2 domain, which reduces protein solubility and impairs RNA binding and cryptic splicing repression functions of MATR3. Altogether, our research identifies cryptic events within functional genes and demonstrates how disease-associated variants impact MATR3 cryptic splicing repression function.

molecular biology↗

Epigenetic reader ZMYND11 noncanonical function restricts HNRNPA1-mediated stress granule formation and oncogenic activity

ZMYND11 encodes an epigenetic reader of histone methylation, functioning as a transcriptional corepressor. However, whether and how ZMYND11 contributes to cancer progression and therapy remains unclear. Here we report that ZMYND11 downregulation is prevalent in cancers and profoundly correlates with adverse prostate cancer patient outcomes. Depletion of ZMYND11 promotes tumor cell growth, migration and invasion in vitro as well as tumor formation and metastasis in vivo. Mechanistically, we find that ZMYND11 exhibits tumor suppressive roles through recognizing arginine-194-methylated HNRNPA1 dependent on its MYND domain, thereby squeezing HNRNPA1 in nucleus and inhibiting the formation of stress granules in cytoplasm. Furthermore, ZMYND11 antagonizes HNRNPA1-driven high PKM2/PKM1 ratio and counteracts PKM2-induced aggressive tumor phenotype. Remarkably, ZMYND11 recognition of HNRNPA1 could be disrupted by pharmaceutical inhibition of arginine methyltransferase PRMT5 while ZMYND11 low-expressing tumors are sensitive to the treatment of PRMT5 inhibitors. Collectively, our study unravels a novel and noncanonical function of ZMYND11 as the nonhistone methyl reader and discovers a mechanism for the requirement of arginine-methylation-mediated ZMYND11-HNRNPA1 association to restrict tumor progression and offers cancer therapeutic targets and potential biomarkers.

cancer biology↗

Ribosomal DNA copy number is associated with body mass in humans and other mammals

Body mass results from a complex interplay between genetics and environment. The contribution of genetic variation to body mass has been extensively studied, but due to the technical limitations of platforms used for population scale studies, repetitive parts of the genome have not previously been considered. Here we applied genome-wide approaches to identify an association between adult body mass and the copy number (CN) of 45S-ribosomal DNA (rDNA). rDNA codes for the rRNA components of the ribosome and exists in hundreds of copies/cell in mammals. Inter-individual variation in rDNA CN has not previously been documented but has not been associated with a mammalian phenotype. Here, we show that germ-line inherited rDNA CN is associated with post-pubertal growth rate in rats and BMI in adult humans. rDNA CN variation is not associated with rRNA transcription rates in adult tissues, suggesting the mechanistic link occurs earlier in development. This is supported by our observation that it is growth rate and body mass, rather than obesity that are associated with copy number and that these phenotypes emerge prior to adulthood. We present hypotheses for future investigation into the mechanistic basis of this association.

genomics↗

Alzheimer's disease associated isoforms of human CD33 distinctively modulate microglial cell responses in 5XFAD mice

Microglia play diverse pathophysiological roles in Alzheimers disease (AD), with genetic susceptibility factors skewing microglial cell function to influence AD risk. CD33 is an immunomodulatory receptor associated with AD susceptibility through a single nucleotide polymorphism that modulates mRNA splicing, skewing protein expression from a long protein isoform (CD33M) to a short isoform (CD33m). Understanding how human CD33 isoforms differentially impact microglial cell function in vivo has been challenging due to functional divergence of CD33 between mice and humans. We address this challenge by studying transgenic mice expressing either of the human CD33 isoforms crossed with the 5XFAD mouse model of amyloidosis and find that human CD33 isoforms have opposing effects on the response of microglia to amyloid-{beta} (A{beta}) deposition. Mice expressing CD33M have increased A{beta} levels, mo7re diffuse plaques, fewer disease-associated microglia, and more dystrophic neurites compared to control 5XFAD mice. Conversely, CD33m promotes plaque compaction and microglia-plaque contacts, and minimizes neuritic plaque pathology, highlighting an AD protective role for this isoform. Protective phenotypes driven by CD33m are detected at an earlier timepoint compared to the more aggressive pathology in CD33M mice that appears at a later timepoint, suggesting that CD33m has a more prominent impact on microglia cell function at earlier stages of disease progression. In addition to divergent roles in modulating phagocytosis, scRNAseq and proteomics analyses demonstrate that CD33m+ microglia upregulate nestin, an intermediate filament involved in cell migration, at plaque contact sites. Overall, our work provides new functional insights into how CD33, as a top genetic susceptibility factor for AD, modulates microglial cell function.

neuroscience↗