Biology subjects

Liu, J.

Publications and source records attributed to Liu, J..

At least 73 records · Page 4Linked to original sources

bioRxiv2026

Mapping First In Vivo Ebolavirus Infection Events

Orthoebolaviruses, including Ebola virus (EBOV) and Bundibugyo virus (BDBV), cause sporadic outbreaks and devastating hemorrhagic infections in humans. A significant challenge that impedes the study of filoviruses is that the infectious virus can only be handled in biosafety level 4 (BSL4) facilities due to their extreme virulence. Life cycle modeling systems that use minigenomes and transcription/replication-competent virus-like particles (trVLPs) are powerful tools for studying these virus biology and to explore antiviral therapies under BSL2 conditions. To date, these powerful tools have only been utilized in vitro in cell culture systems. In this work, we demonstrate the use of EBOV trVLPs in vivo. We report the fine specificity of first infection events in a model of EBOV injection in the skin. Cre recombinase expressing monocistronic EBOV trVLPs were packaged and used to inject Cre reporter mice intradermally (ID). Initial infection events were monitored in living animals by luciferase imaging and then by flow cytometry to track cell-specific expression of Cre-activated GFP. By this approach, EBOV trVLPs were shown to directly infect T cells, monocytes, dendritic cells (DCs) with notably high first infections of skin-resident Langerhans cells (LCs) in the skin barrier and its draining lymph node. EBOV trVLPs were next tested as an in vivo tool to assess antiviral therapies by testing the ability of an EBOV vaccine to reduce trVLP luciferase levels after infection in the skin. This work demonstrates first in vivo use of EBOV trVLPs and provides proof of concept for their use as an in vivo BSL2 model to more rapidly develop antiviral agents and vaccines.

microbiology↗

bioRxiv2026

Dual-Binding Scaffold RRsS1 Bridges Pol IV Transcripts and DNA Templates for Robust Reproductive siRNA Biogenesis

Cytosine DNA methylation established by RNA-directed DNA methylation (RdDM) is critical for transposon silencing and genome integrity in plants. In reproductive tissues, RNA Polymerase IV (Pol IV) is recruited to specific genomic loci by DNA motifs and the transcription factor-GDE1-CLSY3/4 complex to initiate abundant siRNA biogenesis and de novo DNA methylation, but the mechanisms that stabilize the Pol IV transcription complex at these sites remain elusive. Using immunoprecipitation-mass spectrometry of the Pol IV complex, we identify Reproductive RdDM siRNA Scaffold 1 (RRsS1) as a novel Pol IV interactor. RRsS1 colocalizes genome-wide with motif-dependent RdDM factors in floral tissues. Loss of RRsS1 significantly impairs 24-nt siRNA accumulation at a subset of CLSY3/4-dependent loci, particularly those exhibiting high Pol IV enrichment. We show that chromatin association of RRsS1 is stabilized by GDE1 and CLSY3/4. Structural modeling and biochemical assays characterize RRsS1 as a chimeric protein containing HRDC, Nudix, and DRBM modules that bind single-stranded DNA (ssDNA) and double-stranded DNA (dsRNA), respectively. Together, our findings support a model in which RRsS1 acts as a dual-binding scaffold, bridging Pol IV-RDR2 transcripts to their DNA templates within transcription bubbles to ensure robust siRNA production during plant reproduction.

plant biology↗

bioRxiv2026

LRRC37A is essential for acrosomal ion homeostasis and male fertility

Mammalian spermatozoa face various challenges during their long march to the destination. As a specialized membrane-bound organelle in the sperm head, the acrosome is particularly sensitive to changes in ionic and osmotic conditions, yet how acrosomal ion homeostasis is maintained remains largely unknown. Here, we show that LRRC37A is required for acrosomal ion homeostasis. Loss of Lrrc37a causes complete male infertility, accompanied by pronounced enlargement and deformation of the acrosome in the sperm head. Acrosome biogenesis was not affected by Lrrc37a knockout during the early stages of spermiogenesis, whereas acrosomal enlargement emerged at later stages and became more pronounced in the epididymis. LRRC37A localized to the outer acrosomal region and interacted with the Na/K-ATPase -subunit isoforms ATP1A1 and ATP1A4. Loss of LRRC37A disrupted the spatial distribution of both isoforms and was accompanied by increased Na within the acrosomal region. In addition, pharmacological perturbation of Na/K-ATPase activity or cellular ion homeostasis induced acrosomal swelling. These findings establish an essential role for LRRC37A in acrosomal ion homeostasis, suggesting that its deficiency may be associated with a distinct form of teratozoospermia characterized by acrosomal enlargement.

cell biology↗

bioRxiv2026

Rad55-Rad57 and Srs2 regulate homology search onset, coordination, reach and inactivation

DNA double-strand break (DSB) repair by homologous recombination entails the coordinated search for a homologous dsDNA molecule by two heterotypic Rad51-ssDNA filaments in eukaryotes. How homology search is regulated in cells remains largely unknown. Using genomic and molecular assays to track spatial chromatin organization and early recombination intermediates, we investigated the roles in homology search of two antagonistic regulators of Rad51-ssDNA filaments metabolism in S. cerevisiae: the Rad51 paralogs Rad55-Rad57 and the 3'-5' ssDNA translocase Srs2. Srs2 promoted the coordinated search between filaments on each DSB ends and inactivated homology search following homology identification. Rad55-Rad57 both stimulated the formation of Rad51-ssDNA filaments and protected them against disruption by Srs2. Together, Rad55-Rad57 and Srs2 enacted a structural proof-reading that resulted in stiffer Rad51-ssDNA filaments competent for genome-wide homology search. This work reveals multiple ways by which the control of Rad51-ssDNA filament metastability by the individual and joint activities of Rad55-Rad57 and Srs2 regulate homology search onset, coordination, reach and inactivation.

molecular biology↗

bioRxiv2026

Seasonal influenza vaccine strain selection by quantifying viral fitness

The long-standing challenge of seasonal influenza vaccines providing poor protection is attributed to the rapid and continuous evolution of the virus. In theory, the recommendation of vaccine strain is to predict the dominant strain with best fitness in the upcoming season. Here, we develop FutureFlu, a biologically-grounded framework that quantifies the fitness score of influenza variants in upcoming seasons, by integrating metrics on three levels: molecular genetic divergence, individual immune escape, and population-scale transmission dynamics. The fitness scores of influenza variants present strong positive correlation with their actual observed frequencies in the next seasons. Validation across 24 seasons of three influenza subtypes shows FutureFlu recommends antigenically matched vaccine strains more frequently than annual recommendations, particularly for challenging subtypes: 83.3% versus 45.8% seasons for A/H3N2, and 75.0% versus 33.3% seasons for B/Victoria. Furthermore, FutureFlu significantly outperforms the currently used methods in vaccine strain selection whether or not there is available antigenic data from hemagglutination inhibition (HI) assay, which provides a valuable supplement for WHO vaccine recommendation. To support global public health implementation, an open online platform (futureflu.com.cn) has been established to offer real-time viral fitness predictions and vaccine recommendations.

evolutionary biology↗

bioRxiv2026

RamiGlyph Captures Microglial Morphological Diversity and Predicts Functional States in Ischemia Reperfusion and Amyloid Pathology

Microglia are resident immune cells of the central nervous system, whose ramified processes rapidly remodel in response to injury. However, how to capture subtle morphological changes and whether functional state can be predicted from morphology remain open questions. Here, we present RamiGlyph, a contrastive learning framework integrating topological and structural features, trained on more than 20,000 reconstructed microglia. RamiGlyph not only distinguishes physiological and pathological states of microglia but also generalizes to neuronal cell type classification. Projection of microglia morphological embeddings revealed a continuum rather than discrete classes, from which a morphology score was derived to quantify dynamic process remodeling. To link morphology with function, Gromov Wasserstein optimal transport was used to align unpaired morphological and functional data across stages of ischemia reperfusion injury and amyloid pathology. These alignment results enable prediction of microglial functional states using RamiGlyph embeddings alone, with prediction reliability increasing upon cell aggregation. In summary, RamiGlyph provides a robust framework for resolving continuous microglial morphological variation and linking morphology to functional states across acute and chronic neuropathological contexts.

bioinformatics↗

bioRxiv2026

Bioplastic Production from simulated 100% in situ Mars resources

A sustained human presence on Mars requires local production of bulk materials, particularly polymers. Prior approaches to space biomanufacturing rely on human waste streams, Earth-sourced consumables, or complex chemical infrastructure, limiting their ability to scale. Here we demonstrate production of polyhydroxyalkanoate (PHA) bioplastic from simulated 100% martian resources: regolith-derived soluble nutrients, acetate electrochemically fixed from martian atmosphere, and water. We screened 16 candidate organisms for growth in a chemically defined Mars medium and identified Cupriavidus necator H16 and Pseudomonas putida KT2440 as promising chassis organisms. Adaptive laboratory evolution totaling more than 1012 cumulative cell divisions improved both species' tolerance to high concentrations of acetate and leached regolith. The top C. necator evolved isolate, referred to as sPL.001, produced more than three-fold higher PHA titer under simulated Mars conditions compared to its parent strain. These results establish a path to polymer production on Mars where consumable mass is derived entirely from local resources, decoupling bulk material production from Earth supply chains.

bioengineering↗

bioRxiv2026

Division-Specific Organization of a Shared Functional Scaffold in the Early-Life Human Brain

Early cognition and behavior emerge from coordinated maturation of functional systems spanning the brain, making cross-division integration essential for defining whole-brain architecture and understanding its role in neurodevelopment. Yet early human functional development is still largely investigated through cortical networks or through isolated, coarsely resolved noncortical structures, leaving unclear how this integrated architecture is organized across the cerebral cortex, subcortex and cerebellum. Moving beyond structure-isolated and adult-derived maps, we create a reproducible, fine-grained Early-Life Whole-Brain Functional Parcellation (UNC-ELF) spanning birth to six years. Using this framework, we identify a shared functional scaffold expressed through distinct division-specific modes: differentiated and dual-polarity cortical organization, spatially graded cerebellar organization with blended functional transition zones, and nucleus-constrained subcortical mosaics of multi-system affiliation. Across early childhood, the scaffold is selectively refined through heterogeneous, nonlinear connectivity trajectories, with major inflections concentrated in infancy. Age-, sex- and prospective cognition-related variation is differentially encoded across distinct connectomic components. Together, these findings reframe early functional brain development as coordinated refinement of a shared but nonuniform whole-brain scaffold and establish UNC-ELF as a unified reference for resolving typical and atypical functional organization across the developing brain.

neuroscience↗

bioRxiv2026

DiffGSP: reversing mRNA diffusion to unlock high-fidelity spatial transcriptomics

Spatial transcriptomics enables gene expression profiling within intact tissues while preserving spatial context, providing unprecedented insights into cellular organization and function. However, mRNA diffusion during tissue processing can cause transcripts originating from adjacent cells to be captured at a given spot. This spatial misalignment challenges a fundamental premise of spatial transcriptomics that measured gene expression faithfully corresponds to its spatial origin, thereby compromising spatial fidelity and potentially biasing biological interpretation. Here, we present DiffGSP, a physics-informed framework that integrates Fick's law with graph signal processing to explicitly model diffusion-induced distortions and recover the underlying spatial gene expression landscape. Comprehensive benchmarking across diverse datasets and evaluation metrics demonstrates the consistent ability of DiffGSP to restore spatial gene expression patterns. By computationally reversing diffusion-induced distortions, DiffGSP enables the discovery of fine anatomical structures in the mouse brain, spatially organized gene modules in the kidney, intratumoral heterogeneity in colorectal cancer, and tertiary lymphoid structures in lung adenocarcinoma. Built on a physically interpretable framework and broadly applicable to sequencing-based spatial transcriptomics technologies, DiffGSP improves the fidelity of spatial gene expression reconstruction and enables more reliable biological interpretation.

bioinformatics↗

bioRxiv2026

Peptide inhibitors recognize prefusion viral fusion proteins with heterogeneous stoichiometry and rapid kinetics

Peptide fusion inhibitors, an important class of antivirals, block viral entry by targeting fusion proteins required for membrane fusion. However, their interactions with intact trimeric fusion proteins remain elusive; direct observation of binding on virions or native-like trimers has been lacking. Here, we developed a single-molecule imaging platform to visualize peptide binding in real time. LP-98 bound HIV-1 Envelope (Env) trimers on virions and, unexpectedly, prefusion-stabilized soluble Env trimers, with higher affinity for virion-associated Env and, among soluble trimers, a mutant Env. RSV fusion-inhibiting T-118 and 4ca similarly engaged prefusion-stabilized fusion (F) trimers with rapid kinetics and high-nanomolar affinities. Binding to prefusion Env or F demonstrates that peptide inhibitors can act earlier than the canonical prehairpin-intermediate model suggests. Individual binding events revealed heterogeneous peptide-to-trimer stoichiometries, with single-peptide occupancy predominating, while stepwise and simultaneous events revealed multiple routes to higher occupancy. These findings expand the canonical model of peptide fusion inhibition and provide previously inaccessible mechanistic insights into how antiviral peptide fusion inhibitors act.

microbiology↗

bioRxiv2026

Dynamic architecture of the Rixosome reveals mechanism of activation and ITS2 processing

Eukaryotic ribosome assembly requires the coordinated processing and extensive remodeling of pre-rRNAs. During late nuclear maturation of the 60S subunit, sequential removal of the internal transcribed spacer 2 (ITS2) is initiated by endonucleolytic cleavage at site C2 by the conserved Las1 nuclease. Las1 acts together with the kinase Grc3 and the Rix1 complex to form the Rixosome, which also functions in transcriptional regulation. However, the assembly of the Rixosome, its recruitment to pre-ribosomes, and its activation for ITS2 cleavage remain unclear. Here, we present cryo-EM structures of the human LAS1 complex, two structures of the isolated Rixosome and nine transition states of Rix1-bound pre-60S particles from Schizosaccharomyces pombe. These structures reveal a dynamic Rixosome architecture in which the heterotetrameric Las1 complex engages one or two copies of the Rix1 complex. Rix1 binding is highly flexible in the human Rixosome but rigid in the yeast complex. The isolated yeast Rixosome remains inactive, but binding to the pre-60S particle triggers a structural rearrangement that allows for substrate engagement and activation of the nuclease. Together, our results define the dynamic architecture of the Rixosome and provide a structural framework for ITS2 processing during nuclear maturation of the eukaryotic 60S ribosomal subunit.

biochemistry↗

bioRxiv2026

Sequential assembly in vivo of the bacteriophage P22 genome translocation channel

Bacteriophage P22 ejects four internal proteins into infected cells to assemble a channel for genome translocation across the cell envelope. However, how these proteins cooperate to build the trans-envelope channel remains enigmatic. Using in situ single-particle cryogenic electron microscopy, we determined near-atomic in vivo structures of P22 infection intermediates, revealing how the tail hub protein gp10 templates the sequential assembly of three internal proteins gp7*, gp20 and gp16 into a ~50-nm trans-envelope channel that extends from the virion into the host cytoplasm. Functional analyses explain why phage DNA can be detected in supernatant fluids during infection by channel-defective mutants. Our structures also provide a mechanistic basis for the long-standing observation that a P22 virion lacking gp16 can be complemented, extra-cytoplasmically, by a co-infecting virion lacking gp20, thereby allowing the genome in the gp16-deficient particle to enter the host cytoplasm.

microbiology↗

bioRxiv2026

An RBP-J-heparan sulfate-dependent gatekeeper directs macrophage fate between inflammatory regulation and osteoclastogenesis

Macrophages in bone possess a unique bi-potential capacity. Different from their primary roles in inflammation and immunity, these cells can differentiate into bone-resorbing osteoclasts. However, it remains unclear how macrophages determine which function to engage in bone, especially when exposed to the same stimulus, such as TNF, which can drive both pathways. Understanding these mechanisms is particularly important in inflammatory bone diseases, such as rheumatoid arthritis, where inflammation and bone resorption are hallmarks. Here, we identified an RBP-J-Hs2st1-2-O-sulfated heparan sulfate (HS)-IFN{beta} ; dependent molecular network that acts as a gatekeeper balancing macrophage fate inclinations in response to TNF. This network integrates cellular outside-in, inside-out, and relayed outside-in pathways. RBP-J deficiency in macrophages shifts TNF action from inflammatory regulation to osteoclastogenesis. Hs2st1, the exclusive biosynthetic enzyme for 2-O sulfation of HS, is a key target suppressed by RBP-J. Loss of Hs2st1 significantly reduces inflammatory osteoclastogenesis and arthritic bone erosion without affecting physiological bone mass. Elevated Hs2st1 expression and 2-O sulfation shift macrophages toward an osteoclastogenic fate, and vice versa. We further identified residues in IFN{beta} ; that are responsible for binding HS. Mutation of these sites diminished HS binding, augmented type I IFN response, and more strongly suppressed osteoclastogenesis. Our findings reveal a previously unrecognized molecular program fine-tuning macrophage fate and function, and highlight potential therapeutic strategies for inflammatory diseases with bone defects.

immunology↗

bioRxiv2026

Microbial valerate is associated with CAR T dysbiosis and its supplementation enhances CAR T function in B-cell lymphoma

Anaerobe-depleting antibiotic exposure is associated with inferior progression-free survival after CD19 CAR T-cell therapy in large B-cell lymphoma, yet the cellular mechanisms linking gut dysbiosis to the CAR T-cell product and whether this imprint is reversible have remained undefined. In two independent CAR-T candidate cohorts, low stool valerate at the time of CAR-T eligibility identified a multi-metabolite-deficient dysbiotic gut microbiome state marked by depletion of fiber-fermenting commensals and loss of carbohydrate-fermentation, SCFA-biosynthesis, and amino-acid metabolism pathways. Reanalysis of single-cell RNA sequencing from 42 lymphoma patients stratified by piperacillin-tazobactam/imipenem/meropenem (PIM) exposure revealed that PIM-exposed CAR T-cell products were CD4-skewed, with significantly elevated AP-1/immediate-early gene (IEG) and cellular activation signatures that together predicted inferior progression-free survival. Ex vivo conditioning of CAR T-cells with valerate produced a chromatin and transcription factor program distinct from butyrate or propionate, characterized by KLF/SP/EGR family engagement, KLF4 promoter opening, and broad induction of AP-1/IEG and MHC class II transcripts, whereas butyrate drove broader chromatin remodeling with TBX21/EOMES/NF-{kappa}B gains and KLF2 promoter closure, and propionate induced an NFY-centered program with preferential commitment to low-mitochondrial-content states. Untargeted metabolomics confirmed valerate uptake and mitochondrial {beta}-oxidation in CAR T-cells, while dietary sodium valerate supplementation in meropenem-treated mice bearing A20 lymphoma significantly reduced tumor burden and extended survival compared with CAR T-cells alone. These findings identify stool valerate as a bedside-deployable biomarker of dysbiosis-imprinted CAR T-cell dysfunction and support ex vivo or dietary valerate supplementation as a clinically tractable strategy to improve CAR-T anti-tumor function in patients with disrupted gut microbiomes.

cancer biology↗

bioRxiv2026

A patient-centric therapeutic paradigm uncouples prostate cancer suppression from systemic metabolic collapse

The clinical benefits of cancer therapies are often compromised by the tolerable adverse effects that impair systemic organismal health and may evolve into latent life threats. Here, we identified profound abiraterone-induced but androgen-independent metabolic perturbations in prostate cancer patients and developed Lifehug-9892 to balance tumor therapy with systemic metabolic homeostasis. By integrating population cohorts with high-resolution metabolomics, we demonstrate that abiraterone induces profound systemic lipidomic dysregulation, characterized by the massive, pathological accumulation of desmosterol. Abiraterone inhibits but stabilizes DHCR24, leading to a metabolic trap in patients showing elevated levels of both desmosterol and cholesterol. Desmosterol accumulation is highly lipotoxic, potently triggering endothelial cell senescence and necrosis, macrophage foam cell formation, murine atherosclerosis, and hepatic senescence. To mechanistically uncouple and therapeutically rescue this systemic metabolic collapse, Lifehug-9892 was rationally designed to selectively retain on-target CYP17A1 inhibition while completely sparing DHCR24 function. Lifehug-9892 maintains potent tumor-suppressive activity while fully preserving the desmosterol-cholesterol metabolic axis and preventing systemic cardiovascular and hepatic damage. Our study uncovers a critical mechanistic link between drug-induced metabolic dysregulation and organismal health in cancer patients, providing a biochemical framework for developing patient-centric targeted therapies that preserve host homeostasis.

cancer biology↗

bioRxiv2026

The Sustained Alteration Of Brain Waves In Cynomolgus Macaques Following Aerosol Infection With Venezuelan Equine Encephalitis Virus Subtype IAB

Venezuelan equine encephalitis virus subtype IAB (VEEV-IAB) is a mosquito-borne virus that can cause fatal encephalitis in humans and equids. During the 20th century, sporadic but widespread outbreaks occurred throughout the Americas. In addition, VEEV-IAB was investigated as a potential biological warfare agent during the Cold War. Currently, no countermeasures are available to treat or prevent human infection. A critical impediment to understanding VEEV-IAB pathogenesis and developing countermeasures is the lack of a detailed disease course in a susceptible animal model. This study evaluated VEEV-IAB disease progression in cynomolgus macaques using advanced telemetry technology to continuously monitor physiological parameters, including temperature, respiration, activity, heart rate, blood pressure, electrocardiography (ECG), and electroencephalography (EEG), following an aerosol challenge of 6.0 log10 PFU. Following infection, all parameters were altered relative to baseline; temperature (+3.1 to +4.0{degrees}C), respiration rate (+45 to +91%), activity [daytime (-29 to -55%) and nighttime (+14 to +34%)], heart rate (-27 to +191%), systolic (+11 to +39%) and diastolic blood pressure (+7 to +39%). Cardiac abnormalities included increases in QTc (Bazett), PR interval, and QRS duration. All EEG frequency bands were rapidly altered (-250% to +4,800%) and did not return to baseline during the 28-day post-infection period. Despite these profound physiological changes, brain tissues collected at 28 dpi showed minimal evidence of viral persistence or pathology. These data demonstrate that VEEV-IAB aerosol infection rapidly and markedly alters physiological parameters regulated by the autonomic nervous system, as well as provides new insights into VEEV-IAB pathogenesis and countermeasure development.

microbiology↗

bioRxiv2026

Genuinely Blind Identification of Sleep Spindles through Trispectral Modulation Analysis

Sleep spindles, transient 11-16 Hz oscillatory bursts, are a defining electrographic feature of non-rem (NREM) sleep and a key biomarker of sleep physiology. A need for efficient and reliable identification of spindles motivates a large literature on automated detection algorithms. In this literature, annotation by trained sleep specialists remains the gold standard against which automated methods are trained, tuned and evaluated. However, inter-scorer agreement among experts is modest, which leaves a significant role for subjective judgment in the definition of a spindle. Finding objective, scorer-independent, criteria for identifying spindles remains an unresolved challenge. We report here a robust, highly specific, and previously unrecognized signature of spindle activity in the fourth-order spectrum (trispectrum), from which we identify the presence of spindles, characterize their waveforms, and obtain an optimal detection filter through a decomposition of the trispectrum (HOSD). Although it is a strictly blind, data-driven method, HOSD-based spindle identification and detection agrees well with expert annotation (median AUROC ~0.9), yet identifies many more events at the native threshold than both human scorers and comparison detectors. Many of these additional detections are confirmed as meeting AASM spindle criteria by four blinded specialists, demonstrating that spindle-like oscillatory bursting is prevalent below conventional human and automated detection thresholds. We observe that N2 sleep is distinguished principally by high-amplitude bursts, while low-amplitude bursting persists throughout NREM sleep, being globally suppressed only in REM sleep. We also describe robust identification of recording-specific spindle waveform properties such as frequency deceleration.

neuroscience↗

bioRxiv2026

Avs2 drives non-canonical tetrameric assembly of trypsin-like domain for anti-phage defense

Bacteria have evolved diverse anti-phage defense systems, with the antiviral STAND family (Avs) representing one of the most diverse and widespread, encompassing at least 90 distinct families, yet only Avs3, Avs4, Avs5 and Avs7 have been well characterized. Here, we elucidated the molecular mechanism of Avs2-trypsin-MBL system, where phage terminase recognition by Avs2 triggers coupled activation of the protease and nuclease activities of trypsin-MBL. Cryo-EM structure of Avs2-trypsin-terminase and biochemical analysis reveal that the binding of terminase ATPase domain triggers the assembly of Avs2 into tetramer, with two unique ATP molecules bridging ATPase active-site recognition by TPR domain. This tetramerization drives the fused trypsin into an active C4-symmetric assembly, an architecture distinct from the conventional non-defense trypsin. Our study unravels the activation mechanism of Avs2-trypsin-MBL system, expanding our understanding on commonality and diversity of widespread Avs-mediated anti-phage immunity, alongside the structural and functional adaption of trypsin.

microbiology↗