bioRxiv Science⌕ Search

Biology subjects

Lee, J.

Publications and source records attributed to Lee, J..

At least 55 records · Page 3Linked to original sources

OmniScore: Universal Scoring of Diverse Biomolecular Complexes via Equivariant Geometry-Aware Discrete Representation Learning

Scoring biomolecular complexes is central to structure assessment and drug discovery, yet the complexes themselves vary widely in pose, size, and molecular composition. A scoring function tuned for one interaction type rarely carries over to another, and most existing methods compound the problem by leaning heavily on task-specific labels. We introduce OmniScore, a universal structure-based framework that learns a shared geometry-aware representation of complexes once and then adapts it to downstream scoring through lightweight task-specific heads. OmniScore couples a graph view and a sequence view of each structure, encodes its three-dimensional geometry, and compresses representations into a compact latent space that a reconstruction module and prediction heads can reuse. We pretrain this backbone on diverse datasets including complexes, monomers, and small molecules with complementary objectives: coordinate recovery, correcting corrupted input tokens, predicting molecular identity, and grounding the representation in structure-level physical quantities. Across the evaluated benchmarks, OmniScore gave the best antibody-antigen and nanobody-antigen quality assessment on all reported metrics compared to state-of-the-art baselines. Its frozen residue embeddings matched the state-of-the-art protein-tokenization method with an average functional-site accuracy of 71.8% on a standard residue-level benchmark. On protein-ligand scoring and ranking benchmarks, it performed on par with methods built specifically for that single task. These results suggest that geometry-aware pretraining can provide a reusable scoring backbone for tasks that depend on interfacial and residue-level structure, within the evaluated settings.

bioinformatics↗

An Open Benchmark for Systems Vaccinology: Insights from the CMI-PB Challenges

Systems vaccinology approaches have identified factors affecting vaccine responses in multiple studies, but the ability of computational models to generalize these findings to unseen data remains unclear. We established a community resource to create and compare models predicting B. pertussis booster vaccination responses and put such modeling approaches to the test. We compiled multi-modal experimental training data from three independent cohorts (n=117 individuals), and asked investigators to predict vaccine responses in a cohort of 54 newly recruited individuals using only their pre-booster vaccination data. We benchmarked a total of 107 computational models. Top-performing models were characterized by workflows that prioritized rigorous data preprocessing, robust imputation of missing data, and the use of multi-omics integration or non-linear machine learning. We identified pre-existing antigen-specific antibody titers and baseline monocyte frequencies as the most consistent predictors of post-vaccination immunity, highlighting the dominant role of individual immune setpoints. We established the resulting datasets and evaluation framework as a community resource to advance predictive immunology and facilitate personalized vaccination strategies.

immunology↗

High temperature-induced diapause transiently primes progeny for dauer formation in C. elegans.

Environmental stress during early development can have lasting effects on reproduction and developmental plasticity in Caenorhabditis elegans. Here, we compared the consequences of two dauer-inducing stressors, high temperature and crowding, on fertility, dauer formation, and intergenerational gene expression. Entry into the dauer stage protected animals from stress-induced sterility, with high-temperatureinduced diapause (HID) providing strong preservation of reproductive capacity. Remarkably, the progeny of temperature-induced post-dauers (PD-temp) displayed a twofold increase in dauer formation upon re-exposure to heat, revealing a transient intergenerational enhancement of HID. This effect was stimulus-specific, as parental heat exposure suppressed pheromone-induced dauer formation in progeny, while parental pheromone exposure did not enhance HID. This increased dauer propensity was reset after a single stress-free generation. RNA-seq across three generations identified a transient F1-specific gene expression signature associated with enhanced dauer formation upon re-exposure to heat. Functional analyses showed that snpc-1.3, F49F1.7, and Y69A2AR.12 promote HID. In parallel, vit-3 expression was selectively reduced in F1 progeny of PD-temp animals, and vit-3 mutants exhibited increased dauer formation at 27{degrees}C, suggesting that vit-3 normally restrains HID. Consistent with previous work from our group implicating RNAi pathways in environmentally induced diapause and inherited stress responses, we find that endogenous RNAi pathways also modulate HID across generations. Multiple RNAi pathway components contributed to HID, while the nuclear RNAi factor nrde-2 was specifically required for the intergenerational increase in dauer formation. Tissue-specific rescue experiments further suggest that coordinated RNAi activity across tissues contributes differently to parental HID and progeny responses. Together, these findings identify HID as a distinct stress-induced developmental program that transiently modifies progeny responses to recurring thermal stress while preserving reproductive fitness. Our results further indicate that the physiological and intergenerational consequences of dauer entry depend on the environmental cue that induces diapause.

genetics↗

Hyperactivation of the AXL-ICD/SIRT2 axis by Amyloid-β impairs astrocytic autophagic flux and exacerbates neuroinflammation

Autophagy dysfunction and neuroinflammation are central to Alzheimer's disease (AD), yet how extracellular amyloid-{beta} (A{beta}) couples to impaired autophagic flux and heightened neuroinflammation remains unknown. Here, we identify the TAM receptor AXL as a molecular transducer that couples A{beta} sensing to the regulation of autophagy and neuroinflammation in astrocytes. A{beta} induces {gamma}-secretase-dependent cleavage of AXL, generating a nuclear intracellular domain (AXL-ICD) that forms phase-separated condensates and activates autophagy gene transcription through SIRT2-mediated recruitment of the RUVBL1/2-INO80 chromatin-remodeling complex. This axis is activated in astrocytes of postmortem AD brains. Concurrently, AXL-ICD binds to the SIRT2 catalytic domain and suppresses its deacetylase activity, increasing -tubulin acetylation and altering microtubule dynamics. While moderate AXL-ICD levels promote autophagic flux, excessive elevation paradoxically triggers microtubule hyperstabilization, thereby impairing autophagosome-lysosome fusion and causing pathological accumulation of autophagosomes and H2O2. The inhibitory peptide AxSBiP disrupts the AXL-ICD/SIRT2 interaction, restores autophagic flux, reduces plaque burden, and normalizes A{beta}-induced H2O2 production and astrogliosis in APP/PS1 mice. We propose the AXL-ICD/SIRT2 axis as an effective therapeutic target to reduce A{beta} burden and neuroinflammation in AD

neuroscience↗

Inhaled black carbon induces depressive-like behavior and enhances stress-related blood-brain molecular vulnerability in mice

Black carbon (BC), a combustion-derived component of fine particulate matter, has been linked to depressive symptoms, but controlled experimental evidence remains limited. We established a controlled BC inhalation model combined with chronic restraint stress (CRS) to determine whether inhaled BC alone induces depressive-like behavior and whether concurrent stress enhances behavioral and molecular vulnerability. Male C57BL/6J mice were assigned to Control, CRS, BC, or BC+CRS groups and exposed for 21 consecutive days, followed by behavioral testing and molecular analyses of plasma-depleted whole blood and stress-related brain regions. BC exposure alone induced depressive-like behavior, and the combined BC+CRS condition showed the most pronounced phenotype. These findings indicate that inhaled BC is sufficient to influence stress-relevant behavior and may heighten vulnerability under chronic stress. At the molecular level, BC shifted peripheral responses toward a stress- and inflammation-associated state with reduced plasticity-related signaling, whereas CRS preferentially engaged glucocorticoid-responsive regulation. Combined BC+CRS exposure further altered plasticity- and transcription-related regulatory programs in blood and stress-related brain regions, with prominent changes in the nucleus accumbens. These condition-dependent molecular patterns suggest that BC engages blood-brain stress-related pathways in a context- and region-specific manner. Together, these findings identify inhaled BC as a neurobehaviorally relevant environmental hazard.

neuroscience↗

Environmental stress and phenotypic tradeoff modulate the adaptive potential of novel coding sequences for de novo gene birth

Novel protein-coding genes can emerge de novo from ancestrally noncoding sequences and promote adaptation to environmental stresses. Previous work proposes that pervasive translation of lowly expressed open reading frames (ORFs) in noncoding regions creates a rich reservoir of 'proto-genes,' of which subsequent acquisition of gene-like properties, such as increased expression, may be favored or purged by natural selection depending on their phenotypic impact. However, whether and how environmental conditions affect the phenotypic impact of proto-genes remains unclear. Here, we experimentally simulated proto-gene evolution in Saccharomyces cerevisiae by individually increasing the expression of nearly a thousand de novo ORFs with prior evidence of native translation under osmotic and endoplasmic-reticulum stress and in control environments. High-throughput phenotyping revealed that growth effects of increased expression varied strongly across environments for de novo ORFs. A follow-up screen across 22 diverse environments revealed a robust positive correlation between environmental stress severity and the mean growth effects of increased de novo ORF expression. At the individual level, 5.4% of tested de novo ORFs conferred beneficial phenotypes in at least one environment, and 83.3% of these also caused deleterious effects elsewhere, revealing widespread phenotypic tradeoffs. We demonstrate that increased expression of the de novo translated ORF YLR112W results in increased growth in the presence of rapamycin through general dampening of the growth-repressing transcriptomic response induced by this drug. Together, these findings demonstrate that stress severity shapes the phenotypic consequences of increased proto-gene expression and shed light on tradeoffs and transcriptome remodeling as mechanisms underlying such environmental dependency.

evolutionary biology↗

AI-driven framework modeling perturbation in brain organoids reveals candidate genes for autism

Autism gene discovery is constrained by the rarity and heterogeneity of damaging variants, requiring large cohorts to identify susceptibility genes. Neural organoids and single-cell foundation models enable perturbation modeling in neurodevelopmental contexts. Here, we show that perturbation-informed foundation modeling of neural organoids can provide functional context for prioritizing candidate genes with genomic and clinical support. We constructed a 3.6-million-cell organoid atlas and trained models to predict genome-wide perturbation responses. Benchmarking 17 models identified a telencephalic neuron-specific model best preserving autism-relevant perturbation structure. Genome-wide profiling revealed two clusters associated with mid-fetal synaptic neuronal processes and early radial glia ubiquitin signaling. These clusters were supported by damaging-variant enrichment and clinical phenotypes across 89,916 family-based samples. Logistic-regression prioritization identified 343 candidates, including 167 in the key clusters, with convergence across TADA signals and recurrent evidence for NBEA and KLHDC10. This framework integrates predicted perturbation effects with genomic evidence to support autism candidate prioritization.

bioinformatics↗

Hypothalamic Cell Type Evolution across Vertebrates

The hypothalamus regulates vital functions and is highly conserved among vertebrates occupying diverse niches, but little is known about the evolution of its cell types. Using comparative single-cell transcriptomics across major vertebrate classes, we identified deeply conserved and clade-specific cell types. While homologous cell types express conserved transcription factors and neuropeptides, their regulatory linkages are often rewired across evolution. The paraventricular nucleus largely retains its neuropeptide expression and responds to dehydration with fine cellular resolution from amphibians to mammals, whereas lamina terminalis neurons are specific to terrestrial vertebrates and exhibit gene expression divergence in cell types activated by dehydration and heat. We propose that a conserved set of keystone cell types sustain essential functions across vertebrates, while flexible gene regulatory programs alongside numerous clade-specific cell types offer evolutionary fluidity.

evolutionary biology↗

Combinatorial Modulation of Wnt, STAT3, TGF-β, and Tie2 Pathways Drives Brain Endothelial Cell-Like Differentiation from hiPSCs

During development, endothelial cells (ECs) migrate into the brain and acquire blood-brain barrier (BBB) properties such as tight junctions, limited transcellular transport, and high electrical resistance. Although key signaling pathways that are active in vivo have been identified, factors critical in inducing brain EC differentiation in vitro remain unclear. Here, we describe conditions that promote brain EC-like gene expression in human pluripotent stem cell (hiPSC)-derived ECs. Activation of Wnt/{beta}-catenin signaling upregulates the brain EC marker GLUT1 (SLC2A1) while suppressing the peripheral EC marker PLVAP. Simultaneously, stimulation of STAT3 by CNTF together with TGF-{beta} inhibition increases CLDN5 expression. We further found that hiPSC-derived ECs secrete high levels of angiopoietin-2 (ANGPT2) and that razuprotafib (AKB-9778), a PTPRB (VE-PTP) inhibitor, inhibits ANGPT2 and improves monolayer integrity. These results suggest that combinatorial modulation of specific signaling pathways stimulates the differentiation of human brain ECs in vitro.

developmental biology↗

WHaloForce enables chemigenetic imaging of molecular tension in living cells and animals

Piconewton forces borne by individual proteins within complex assemblies underlie cell adhesion, migration, and tissue morphogenesis, yet remain difficult to image in living systems. Here, we introduce WHaloForce, a chemigenetic HaloTag-based tension sensor that converts force-dependent relief of tryptophan-mediated dye quenching into a fluorescence lifetime change. Optical tweezers revealed a switch-like unquenching transition near 5 pN, and the sensor responded reversibly to force changes in cells. WHaloForce enabled quantitative tension imaging of diverse force-bearing proteins (vinculin, E-cadherin, -catenin, and laminin) in mammalian cells, mouse tissue, and C. elegans. Bright synthetic dyes made tension measurements possible at endogenous expression levels. In C. elegans, vinculin and laminin showed opposite tension patterns between tissues, revealing distinct force-transmission routes through adhesions and the extracellular matrix. During ovulation, laminin tension accumulated over repeated stretch-relaxation cycles, scaling with cumulative loading history. WHaloForce thus offers a modular platform for imaging spatiotemporal tension patterns in living systems.

cell biology↗

Slower cardiac-coupled cortical dynamics link depressive symptoms to inflexible affective updating

Depression is marked by blunted affective responses to context, which interoceptive accounts trace to altered neural representations of bodily states. Yet this evidence mainly concerns response magnitude, not how quickly affect is updated when contexts change. Here we tested whether depressive symptom severity is related to delayed affective updating, and whether cortical dynamics tracking cardiac states account for this delay. To this end, we applied a movie-watching paradigm with independently defined contextual shifts, continuous affect ratings, electroencephalography, and electrocardiography in individuals spanning a continuum of depressive symptoms. Combining deep representation learning and a dynamical systems framework, we quantified how quickly (speed) and how sharply (angle) cardiac-coupled cortical representations reorganized at each shift. Greater symptom severity predicted longer latency to enter the context-congruent affective state across contextual shifts, regardless of valence. In a cross-sectional mediation analysis, slower speed, but not angle, accounted for this association. This mediation was specific to depressive symptoms, contextual shifts, and cardiac-coupled neural dynamics. These findings extend the embodied account of depression from blunted affective intensity toward its inflexible updating at moments of contextual shift, and offer a broadly applicable framework for quantifying brain-body dynamics across affective dysfunctions.

neuroscience↗

LEN-Seek: Fast and scalable ligand binding-site similarity search in the latent space of an SE(3)-invariant graph VAE

MotivationLigand binding-site similarity search is a crucial step in drug discovery that reduces the conformational search space for docking and other downstream tasks by comparing a target protein against experimentally identified binding sites. Existing methods rely on either direct structural alignment or lossy compression of structural information, producing a trade-off between scalability and precision. ResultsWe propose LEN-Seek, a ligand binding-site search method based on a graph neural network (GNN)-driven variational autoencoder (VAE) that encodes the 3D structural and physicochemical context of a binding site into a probabilistic latent space, enabling similarity search within a low-dimensional vector space. A binding site is modeled as a graph of amino acid residues, with node features adopted from the protein language model, Ankh, and edges encoded as SE(3)-invariant (roto-translational invariant) geometric relationships, thereby avoiding expensive data augmentation or SE(3)-equivariant models. Compared to ProBiS, the purely geometric graph-clique based method, LEN-Seek successfully retrieves a substantial portion of similar binding sites with a roughly 3,400-fold lower per-comparison cost, demonstrating its potential as a scalable approach to template-based ligand binding-site search in large-scale protein structure databases. Supplementary informationSupplementary data are available at Bioinformatics online.

bioinformatics↗

Programmable genetic control of tumor-colonizing Bifidobacterium longum for intratumoral therapeutic delivery and biocontainment

Engineered bacteria offer a distinct modality for cancer therapy by exploiting the ability of certain species to colonize tumors and deliver therapeutic payloads. Improving their efficacy and safety requires control over bacterial activity after tumor colonization, yet few microbial chassis permit it. Bifidobacterium longum, a probiotic with intrinsic tumor-targeting and antitumor activity, is a promising chassis but lacks such control. Here, we develop a genetic control system that regulates B. longum activity within tumors, from gene expression to bacterial abundance. A human-isolate-derived replicon supports plasmid maintenance without antibiotic selection, and promoter and ribosome-binding-site libraries provide [~]150-fold and [~]48-fold expression ranges, respectively. Signal peptides enable secretion of structurally diverse therapeutic payloads and B. longum secreting CCL21 or an anti-PD-L1 nanobody reduces tumor growth relative to PBS controls. Anhydrotetracycline delivered in drinking water induces transgene expression in tumor-resident bacteria and reduces intratumoral bacterial load through CRISPRi targeting essential genes. Together, these results establish a tumor-homing probiotic as an externally controllable therapeutic chassis.

synthetic biology↗

Characterization of the frameshift c.515dupC knock-in mouse model of HSPB8-associated myopathy (MFM13) and evaluation of Trehalose as autophagy modulating therapy.

Heat shock protein family B member 8 (HSPB8) is a chaperone involved in the chaperone-assisted selective autophagy (CASA) complex. HSPB8 in conjunction with cochaperone BAG3, promotes autophagy-mediated removal of misfolded proteins associated with various neurodegenerative diseases. Mutations in HSPB8, previously associated with Charcot Marie Tooth disease type 2L, have recently been linked to an autosomal dominant rimmed vacuolar myopathy (MFM13), and is considered a multisystem proteinopathy. Patients have distal and proximal limb girdle myopathy with muscle biopsy showing fatty replacement, endomysial fibrosis, and rimmed vacuoles leading to muscle atrophy and early demise. We have demonstrated reduced expression of HSPB8, altered autophagy and TDP-43 accumulation in patient fibroblasts. Using CRISPR technology, we generated a knock-in Hspb8 mouse model of the c.515dupC hot spot frameshift variant to study disease pathology. Overexpressed murine Hspb8 frameshift mutant (c.515dupC, fs) displays insolubility and aggregation propensity in Murine Neuroblastoma X Spinal Cord 34 (NSC-34) cells. Mutant Hspb8 mice developed late-onset muscle weakness beginning at 15 months. Muscle biochemical analyses revealed reduced HSPB8 levels, increased TDP-43, and altered autophagy markers, partially recapitulating the human phenotype. Fiber type analysis, neuromuscular junction integrity, and motor neurons show mild myopathy without neurodegeneration. Given the lack of available treatments, we evaluated trehalose, a natural disaccharide that induces HSPB8 and enhances autophagy. Administration of 2% trehalose in drinking water improves motor performance, restores HSPB8 expression, and ameliorates autophagic and TDP-43 pathology in mutant mice. These findings support the value of our preclinical models for translational studies, and autophagy enhancement as a potential therapeutic strategy for HSPB8-related myopathy.

genetics↗

A modular cranial window enabling maintainable widefield optical access in non-human primates

Longitudinal optical imaging of the primate cortex requires stable yet maintainable cortical access, but existing cranial window approaches remain limited by mechanical instability and tissue responses that progressively degrade optical clarity. These challenges are amplified in primates, where large craniotomies and physiological variability complicate chronic experiments. Moving beyond conventional fixed cranial windows, we present the PRIME cranial window (Primate Reconfigurable Interchangeable Modular Enclosure), a modular platform enabling maintainable, long-term, and widefield optical access in awake macaques. Built on a modular architecture, PRIME supports non-invasive adjustment, repeated cortical access, and on-demand maintenance, including tissue removal, without surgical re-entry, while a dual-ring sealing mechanism prevents cerebrospinal fluid leakage and contamination. Combined with optimized viral delivery, implantation, and maintenance strategies, PRIME preserves cortical integrity and optical clarity for long-term optical imaging. PRIME establishes a versatile, re-accessible experimental framework for chronic, large-area optical studies of the primate brain.

neuroscience↗

Primary Cilia Loss in Striatal Neurons Disrupts Synaptic Connectivity and Excitatory Transmission and Drives Metabolomic Remodeling

Disruption of striatal circuits is a central feature of many neurological and psychiatric disorders, yet the mechanisms that maintain afferent connectivity and synaptic function in striatal neurons remain incompletely defined. Primary cilia are signaling organelles present on almost all striatal medium spiny neurons that are enriched in neuromodulatory receptors, suggesting a role in coordinating striatal neuronal communication and biochemical state. Here, we show that conditional ablation of primary cilia from striatal neurons by AAV-Cre-mediated deletion of Ift88 disrupts the afferent connectivity, synaptic function, and chemical signature of the striatum. Monosynaptic rabies tracing revealed an approximately threefold reduction in brain-wide input convergence onto striatal neurons. Whole-cell recordings showed reduced miniature excitatory postsynaptic current amplitude and frequency together with a reduced NMDA:AMPA ratio, consistent with weakened glutamatergic synaptic transmission. Untargeted metabolomics revealed broad remodeling of the striatal chemical profile, predominantly toward decreased measured levels, with lipid-associated pathways most affected alongside reductions in polyamines, glutamate-related metabolites, and neuromodulatory, particularly excitatory, signaling molecules. By contrast, the cortex, which was not targeted by the AAV injection, showed fewer and directionally opposite molecular changes. These findings identify cilia as essential regulators of the structural, synaptic, and molecular integrity required for normal striatal circuit function.

neuroscience↗

Hypergraph geometry localizes mutation-associated dependency vulnerabilities in cancer.

Mutation-specific therapeutic vulnerabilities remain difficult to identify in precision oncology because lineage effects and network topology can obscure true synthetic lethal relationships. Here, we present a computational framework that maps genomic mutational profiles and genome-wide CRISPR-Cas9 screens onto multi-scale hypergraphs constructed from macromolecular complexes (CORUM), protein interaction modules (STRING), and transcriptional regulons (TRRUST). Using strict reproducibility criteria across lineage-split cohorts, we identify cross-topology overlap families of dependencies that recur across independent biological organizational layers. We then characterize these candidates with discrete hypergraph geometry, including Hypergraph Fractional Ricci Curvature (HFRC) and Hypergraph Local Ricci Curvature (HLRC), and evaluate them against multidimensional matched-null distributions and degree-preserving shuffles to control for network density and node degree bias. We evaluate the 8 core cross-topology families for clinical prognostic value. Separately, to validate the pharmacological actionability of the hypergraph framework, we project our prioritized candidates onto PRISM dose-response profiles, confirming that the geometrically constrained BRAF:MAP2K1 family exhibits strong, selective drug sensitivity to downstream MAPK pathway inhibition. The strongest face-validity result is SMARCA2:SMARCA4, a clinically validated paralog synthetic lethal pair in chromatin remodeling that our pipeline recovered purely through unsupervised geometric constraints. While across the prioritized overlap families this specific class of reproducible dependencies localizes to highly integrated, negatively curved hypergraph regions, this topological separation is statistically fragile; it achieves nominal significance (p = 0.031) as a primary endpoint and is sensitive to the removal of single families. Nonetheless, this pattern persists across independent screening platforms, including Sanger and DepMap 25Q3, suggesting a potential, albeit statistically sensitive, geometric framework for prioritizing actionable targets in precision oncology.

bioinformatics↗

Endolysosomal acidification regulates intestinal injury and repair in Drosophila by augmenting JNK activation and innate immune signaling pathways

Vacuolar ATPases (V-ATPases) are highly conserved multi-subunit proton pumps that drive the acidification of intracellular vesicles, especially endosomes and lysosomes. Beyond enabling cargo degradation, endolysosomal acidification shapes signal transduction, acting both positively through receptor processing in endosomes and negatively through lysosomal turnover of pathway mediators. Whether endolysosomal acidification shapes the intestinal epithelial response to oxidative injury remains unclear. Here we use Drosophila to define the role of V-ATPases in intestinal injury driven by excessive oxidative stress. Consistent with lysosomal biogenesis programs induced by oxidant in other systems, we find that oxidant exposure increases V-ATPase subunit expression and abundance of acidified vesicles in the midgut. Yet this response is not protective. RNAi depletion of multiple V-ATPase subunits suppresses lethality induced by either hydrogen peroxide or paraquat exposure. These effects map to mature absorptive enterocytes rather than to intestinal progenitors. Enterocyte-specific depletion of Vha44 (subunit C of the V1 domain) preserves intestinal barrier function and suppresses the cell death, JNK pathway activation, and IMD/NF-{kappa}B reporter activity induced by oxidant exposure. Overexpression of the MAP3K Tak1 sensitizes animals to oxidative stress and drives JNK and IMD signaling, both of which require Vha44. Together, these findings identify endolysosomal acidification as an amplifier of pro-apoptotic JNK and IMD/NF-{kappa}B signaling, such that attenuating V-ATPase levels in mature enterocytes protects the intestinal epithelium from excessive oxidant burden.

cell biology↗