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Biology subjects

LI, J.

Publications and source records attributed to LI, J..

At least 19 recordsLinked to original sources
bioRxiv2026

Plant regulator of flower bud differentiation in in vitro plants of Cymbidium tortisepalum var. longibracteatum with TDZ as the key initiator

BackgroundCymbidium tortisepalum var. longibracteatum is a Class II nationally protected endangered plant in China with significant economic value. AimThis study aimed to establish an efficient in vitro flowering system and identify key hormonal factors regulating flower bud differentiation. MethodsOrthogonal experiments and hormone treatments were performed to evaluate the effects of TDZ, 6-BA, NAA, IBA, PP333, ABA, and GA3 on flower bud induction in tissue-cultured plantlets. ResultsTDZ was identified as the key initiator of flower bud differentiation, as no flower buds were induced in TDZ-free treatments. The optimal hormone combination was 1.0 mg{middle dot}L-1 6-BA + 0.4 mg{middle dot}L-1 TDZ + 0.8 mg{middle dot}L-1 NAA + 1.6 mg{middle dot}L-1 IBA, achieving a flower bud induction rate of 23.33% and a normal flower bud rate of 20.00%. PP333 inhibited flower bud differentiation but reduced malformation; at 0.2 mg{middle dot}L-1 PP333, the normal flower bud rate reached 20.00%. GA3 pretreatment resulted in a flower bud induction rate of 12.04%, whereas ABA pretreatment showed no significant promoting effect on flower bud induction. ConclusionsThis study provides an efficient in vitro flowering system and key hormonal parameters for shortening the breeding cycle and elucidating orchid flowering mechanisms.

plant biology↗
bioRxiv2026

An active-matrix digital microfluidic platform for simultaneous short- and long-read viral genomic surveillance

The outbreak frequency and geographic distribution of viral pathogens are continuously expanding, making enhanced genomic surveillance an urgent global public health need. Parallel library preparation combining next-generation sequencing (NGS) and third-generation sequencing (TGS) can substantially improve the coverage and resolution of genomic surveillance, representing a key strategy for strengthening surveillance. Here we developed a complete sample-to-result system integrating a programmable active-matrix digital microfluidic (AM-DMF) chip with a bioinformatics analysis pipeline. Compared with conventional manual protocols used in public health laboratories, our system reduces reagent consumption by 72%, shortens library preparation time by 45% and decreases the inter-batch coefficient of variation (CV) by 20%. In 20 RT-qPCR-confirmed clinical samples, the system achieved complete concordance for viral identification and assigned serotypes/genotypes consistent with sequencing-based phylogenetic analysis. This system is field-deployable and enables rapid virus serotyping as well as in-depth genomic surveillance. TeaserA digital microfluidic platform integrating short- and long-read sequencing enables rapid comprehensive viral genome analysis.

bioengineering↗
bioRxiv2025

Scaffolded hiPSC liver organoids recapitulating bile duct tubulogenesis and periportal architecture.

Recapitulating the liver periportal area in vitro remains a major challenge due to its complex cellular composition and the coordinated development of both ductal and endothelial networks. Most existing bile duct organoid models fail to reproduce tubular extension and multicellular organization. We present a 3D ECM micro-rods system biofunctionalized with grafted growth factors mimicking fetal liver paracrine signaling to initiate and to coordinate the development of bile ducts, parenchymal cells, and vascular structures. Our system recapitulates key developmental stages, from the formation of the ductal plate to the emergence of elongated tubular ducts. The ECM rod alone provides the biophysical cues initiating the elongation of the bile ducts and the spatial structuration of the cellular organization, while the biofunctionalization with growth factors enhance the organization and maturation of the biliary and vascular systems. We further demonstrate that this approach is scalable and amenable to quantitative analysis through label-free Optical Coherence Tomography combined with AI-driven 3D segmentation.

cell biology↗
bioRxiv2025

Structural assembly of maize CRY-GL2 photosignaling complex provides insights into its regulatory role in cuticular wax biosynthesis

Cryptochromes (CRYs) are blue-light photoreceptors in plants that regulate diverse physiological processes through oligomerization-dependent interactions with downstream effectors. While numerous light-inducible CRY-binding proteins have been identified, the structural basis for photoactivated CRY-effector assembly remains poorly understood. Here we report the crystal structure of a constitutively active maize CRY1c photolyase homology region (ZmCRY1c-PHRW368A) in complex with ZmGL2, a BAHD ptotein directing very-long-chain fatty acid (VLCFA) elongation for cuticular wax biosynthesis. Structural analysis reveals that light-activated ZmCRY1c forms a homotetrameric scaffold generating four symmetric binding sites at subunit interfaces. Each ZmCRY1c protomer engages one ZmGL2 molecule through conformational reorganization of its 16-17 loop and 17 helix, establishing a 4:4 hetero-octameric photosignaling complex validated by mutational profiling and optical design. Remarkably, structural alignment with the ZmCER6-ZmGL2 complex reveals substantial overlap (78%) in ZmGL2 binding interfaces. Biochemical quantification demonstrates that ZmCRY1c suppresses ZmCER6-GL2 enzyme activity in a dose dependent manner, unveiling a light-dependent regulatory switch controlling VLCFA elongation efficiency, though in vivo physiological investigation is awaited. Collectively, our work not only establishes the atomic model of light-activated plant CRY-effector assembly, but also uncovers a previously unrecognized spatial competition between photoreceptor and metabolic enzyme complexes that might function as a photoregulatory paradigm in cuticular wax biosynthesis.

plant biology↗
bioRxiv2025

A coupled fluorescence assay for high-throughput screening of polyurethane-degrading enzymes

The global accumulation of plastic waste, particularly persistent polymers like polyurethane (PU), demands urgent solutions. Enzymatic depolymerization offers a viable strategy for PU waste valorization. However, progress has been hindered by the lack of reliable high-throughput screening (HTS) assays capable of precise and quantitative evaluation of enzymatic activity. Current enzyme screening assays face significant limitations due to poor substrate relevance and inadequate quantification methods. Here, we present a novel HTS assay featuring a chemically defined, synthetic poly (ethylene adipate)-based PU substrate that enables unambiguous structure-activity analysis and direct quantification of degradation products (adipic acid and ethylene glycol). Coupled with this substrate is a highly sensitive fluorescence-based detection cascade, in which released ethylene glycol is stoichiometrically converted to resorufin via a two-enzyme system (glycerol dehydrogenase and diaphorase). This assay overcomes key limitations of commercial substrates (e.g., Impranil DLN) by providing quantitative, real-time monitoring of PU hydrolysis with molecular precision. Validation with known PU-degrading enzymes demonstrated that the assay can sensitively distinguish differences in enzymatic activity with high reproducibility and quantitative accuracy. Our platform enables rapid, cost-effective screening of enzyme libraries and engineered variants, significantly advancing enzyme discovery and optimization efforts. By bridging the gap between laboratory research and industrial application, this HTS assay accelerates the development of sustainable PU recycling solutions, offering a critical tool against plastic pollution. Graphical Abstract Legend O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/663332v4_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@17ba5c0org.highwire.dtl.DTLVardef@bef89aorg.highwire.dtl.DTLVardef@1b3770eorg.highwire.dtl.DTLVardef@14d5ef5_HPS_FORMAT_FIGEXP M_FIG (A) Workflow of the enzymatic degradation assay. Enzymes are incubated with chemically defined PEA-PU films. The resulting hydrolysate is collected and analysed using a fluorescence-based assay in microplate format (Ex/Em = 535/588 nm). (B) Fluorescence-based detection mechanism. Assay principle based on ethylene glycol (EG), one of the major degradation products. EG is converted through a two-step enzymatic cascade involving glycerol dehydrogenase (GldA) and diaphorase, leading to the generation of fluorescent resorufin from resazurin. C_FIG

synthetic biology↗
bioRxiv2025

Protein Phosphatase 2A Subunit B55 Alpha is Required for Angiotensin Type 2 Receptor Elicited Natriuresis

BackgroundAngiotensin type 2 receptor (AT2R) activation promotes natriuresis in renal proximal tubule cells (RPTCs) counteracting sodium retention stimulated by the AT1R. Early signaling events mediating the natriuretic response with AT2R activation in RPTCs are currently unknown. Our previous research suggested protein phosphatase 2A (PP2A) functions downstream of the AT2R. In this study, we investigated the interaction of PP2A regulatory subunit B55 with the AT2R and requirement for B55 in AT2R signaling and natriuresis. Methods and ResultsRats were subjected to renal interstitial (RI) infusion of vehicle or Compound 21 (C21), a non-peptide specific AT2R agonist, and kidney sections were probed for interactions between PP2A subunits and the AT2R using a proximity ligation assay. A dramatic 6-fold increase in AT2R-B55 interaction in apical brush border membranes of RPTCs was observed with C21 stimulation. In vitro binding of purified AT2R and B55 supported a direct interaction between these two proteins. To determine the requirement for B55 in renal AT2R signaling, siRNA targeting B55 was administered to rats in vivo by RI infusion which resulted in a [~]70% decrease in B55 in RPTCs but not distal tubules. In rats with B55 knockdown in RPTCs, natriuresis in response to C21 was abolished. Simultaneously, C21-elicited AT2R redistribution to and sodium transporter Na+/H+ exchanger-3 (NHE3) retrieval from apical brush border membranes was lost, as observed with confocal immunofluorescence microscopy. Consistent with impaired AT2R signaling, B55 knockdown prevented c-Src phosphorylation in response to C21. B55 knockdown also led to a dramatic 4 to 6-fold increase in AT2R co-localization with the lysosomal marker LAMP1, and a 50% reduction in AT2R co-localization with EEA1 and Rab 7, markers for early and late endosomes, respectively. ConclusionsPP2A B55 directly binds to the activated AT2R and is required for AT2R-elicited natriuresis, AT2R signaling and intracellular trafficking in RPTCs.

physiology↗
bioRxiv2025

RIPK3-dependent sequential recruitment of MLKL and RIPK1 drives PANoptotic cell death and chemokine production

PANoptosis, an immunogenic programmed cell death (PCD) modality, integrates features of pyroptosis, apoptosis, and necroptosis through assembly of the PANoptosome complex. Despite its conceptualization as a distinct PCD form, PANoptosis remains controversial due to insufficient characterization of its morphological hallmarks and molecular regulation. This study aimed to investigate the molecular mechanisms underlying the assembly of PANoptosomes in the PANoptotic pathway. We identified a novel receptor-interacting protein kinase 3 (RIPK3)-initiated PANoptotic pathway that functions without pattern recognition receptors (PRRs) and the ASC (apoptosis-associated speck-like protein containing a CARD) inflammasome. Using multimodal imaging and biochemical approaches, we identify unique morphological signatures distinguishing PANoptotic cells from canonical pyroptotic, apoptotic, or necroptotic counterparts. Mechanistically, RIPK3 forms round homopolymeric scaffolds--distinct from necroptotic amyloid-like fibers--to sequentially recruit MLKL and RIPK1, forming a dynamic RIPK3-MLKL-RIPK1-FADD-caspase-8 complex (RIPK3-PANoptosome). This platform coordinates concurrent activation of pyroptotic, apoptotic, and necroptotic effectors. Cross-regulatory interactions between these pathways establish a homeostatic system where perturbations bias death modality into a certain cell death type, altering the death process and outcomes. Functionally, PANoptotic cells orchestrate chemokine secretion through parallel kinase-dependent (RIPK3-MLKL) and kinase-independent (RIPK1-IKK-NF-{kappa}B) mechanisms, driving macrophage recruitment. Our findings resolve the molecular logic of PANoptosome assembly, redefine PANoptosis as a tunable PCD paradigm, and establish its role in immunomodulation, providing a framework for targeting inflammatory cell death in disease.

cell biology↗
bioRxiv2025

Infectome Analysis of Small Mammals in Southern China Reveals Ecological Associations and Emerging Threats from Diverse Pathogens

Small mammals harbor a diverse array of zoonotic pathogens. To date, however, metagenomic surveys of these species have primarily focused on viral diversity, with limited attention paid to bacteria and eukaryotic pathogens. Additionally, the ecological determinants of pathogen diversity within these mammals have not been systematically examined. Herein, we employed a metatranscriptomics approach to survey the pathogen infectome of 2,408 individual samples, representing lung, liver, and gut tissues from 858 animals collected throughout Guangdong province, China, with a study design that accounted for host species, tissue, season, and geographic location. We identified 76 pathogen species, including 29 RNA viruses, 12 DNA viruses, 5 bacteria, and 30 eukaryotic pathogens, 33 of which were newly discovered. Tissue distribution analysis revealed distinct organotropisms, suggesting varied transmission routes, while host distribution analysis showed that each animal carried an average of one pathogen, with 10 pathogens widely distributed among mammalian orders. Our characterization of the geographic and seasonal patterns revealed that pathogen richness was primarily influenced by region, host species, and season, while pathogen composition was largely shaped by host genetic distance. Collectively, these data provide the first comprehensive insight into the dynamics of the pathogen infectome in these key mammalian disease reservoirs, highlighting the major factors driving pathogen diversity and transmission.

microbiology↗
bioRxiv2024

Chemically Induced Nuclear Pore Complex Protein Degradation via E3 Ligase TRIM21

Despite the exciting progress of the bifunctional degrader molecules, also known as proteolysis-targeting chimeras (PROTACs), the rapidly expanding field is still significantly hampered by the lacking of available E3 ligase ligands. Our research bridges this gap by uncovering a series of small-molecule ligands to the E3 ligase TRIM21 through DNA-Encoded Library (DEL) technology. We confirmed their interaction with TRIM21 using crystallography and demonstrated their anti-proliferative effects across various cancer cell types. Furthermore, proteomic studies identified that the mRNA Export Factor GLE1, and the Nuclear Pore Complex Protein NUP155, were significantly down-regulated upon TRIM21 ligand treatment. This degradation required TRIM21 and was ubiquitin-proteasome-dependent. More specifically, NUP155 was the primary target for the TRIM21 ligands, while GLE1 was considered a passenger target upon the initial degradation of NUP155. Using immunofluorescence techniques, we further demonstrated that the degradation of GLE1 and NUP155 proteins impaired the integrity of the nuclear envelope, leading to cell death. Highlighted by this research, a novel mode of action has been discovered for the TRIM21 E3 ligase ligand, acting as a monovalent degrader that triggers de novo interaction with functional complex proteins and induces their degradation.

cell biology↗
bioRxiv2024

Orchestrating the Acquisition of Oligodendrocyte Precursor Cell versus Olfactory Bulb Interneuron Fates through Olig1/2 during Mammalian Cortical Gliogenesis and Gliomagenesis

The hijacking of developmental gliogenesis programs is a hallmark of glioblastoma (GBM), in which glial precursor cells (GPCs) typically differentiate into both neurons and glial cells. In GBM, this process is disrupted, leading to the overproduction of proliferative glial-like cells. Our study demonstrates that the knockout of Olig1/2 in both normal development and gliomagenesis causes GPCs to shift from generating highly proliferative oligodendrocyte precursor cells to producing non-proliferative olfactory bulb interneurons. Mechanistically, Olig1/2 play dual roles by orchestrating distinct transcriptional programs in GPCs, particularly inhibiting the expression of Gsx2 through direct binding to its multiple enhancers. Additionally, we provide compelling evidence that human H3.3G34R/V-mutant tumors, a subtype of high-grade gliomas, originate from dorsal cortical-derived GPCs rather than from the previously assumed progenitors in the ventral basal ganglia. Collectively, our findings reveal a previously unrecognized role of Olig1/2 in both gliogenesis and gliomagenesis, offering deeper insights into the connections between normal neural development and tumorigenesis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=159 HEIGHT=200 SRC="FIGDIR/small/623106v1_ufig1.gif" ALT="Figure 1"> View larger version (69K): org.highwire.dtl.DTLVardef@10ea118org.highwire.dtl.DTLVardef@1725006org.highwire.dtl.DTLVardef@1e3ce25org.highwire.dtl.DTLVardef@f300ee_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗
bioRxiv2021

Water Pollution and Administrative Division Adjustments: A Quasi-natural Experiment in Chaohu Lake of China

The adjustment of administrative divisions introduces a series of uncertain impacts on the social and economic development in the administrative region. Previous studies focused more on the economic effects of the adjustment of administrative divisions, while, in this paper, we also take environmental effects into consideration. The administrative division adjustment for Chaohu Lake is used as a quasi-natural experiment to explore the influence of the adjustment on pollution control. The synthetic control method is used in this study to access the effect of administrative division adjustment on the water quality indicators of Chaohu Lake and its internal mechanism. Some conclusions are as follows. First, after the administrative division adjustment, some water quality indicators, such as ammonia nitrogen, have indeed been alleviated; however, other major pollution indicators, such as chemical oxygen demand and dissolved oxygen, have deteriorated to varying degrees. Second, the results also reveal that improper development ideas, industrial excessive expansion, and the swing of economic growth and environmental goals are problems after the adjustment. Returning to the original intention of adjustment, rationalizing the Chaohu Lake management system and designing a sound and feasible accountability mechanism are fundamental measures to reduce pollution.

ecology↗
bioRxiv2021

Genetic characteristics of human papillomavirus type 16, 18, 52 and 58 in southern China

Persistent infections of high-risk human papillomaviruses (HPVs) are the leading cause of cervical cancers. We collected cervical exfoliated cell samples from females in Changsha city, Hunan Province and obtained 358 viral genomes of four major HPV types, including HPV 16 (n=82), 18 (n=35), 52 (n=121) and 58 (n=100). The lineage/sublineage distribution of the four HPVs confirmed previous epidemiological reports, with the predominant prevailing sublineage as A4 (50%), A1 (37%) and A3 (13%) for HPV16, A1 (83%) for HPV18, B2 (86%) for HPV52 and A1 (65%), A3 (19%) and A2 (12%) for HPV58. We also identified two potentially novel HPV18 sublineages, i.e. A6 and A7. Virus mutation analysis further revealed the presence of HPV16 and HPV58 strains associated with potentially high oncogenicity. These findings expanded our knowledge on the HPV genetic diversity in China, providing valuable evidence to facilitate HPV DNA screening, vaccine effectiveness evaluation and control strategy development.

genomics↗
bioRxiv2021

Mutation Profiles, Glycosylation Site Distribution and Codon Usage Bias of HPV16

Human papillomavirus type 16 (HPV16) is the most prevalent HPV type causing cervical cancers. Herein, using 1,597 full genomes of HPV16, we systemically investigated the mutation profiles, surface protein glycosylation sites and the codon usage bias of the eight open reading frames (ORFs) of HPV16 genomes from different lineages and sublineages. Multiple lineage- or sublineage-specific mutation sites were identified. Glycosylation analysis showed that HPV16 lineage D contained the highest number of unique potential glycosylation site in both L1 and L2 capsid protein, which might lead to their antigenic distances from other HPV16 lineages. Nucleotide composition of HPV16 showed that the overall AT content was higher than GC content at the 3rd codon position. Relatively high ENC values suggested that the HPV16 ORFs didnt have strong codon usage bias. Most of the HPV16 ORFs were mainly governed by natural selection pressure such as translational pressure, except for L2. HPV16 only shared some of the preferred codons with human, which might help reduce competition in translational resources. These findings may help increase our understanding of the heterogeneity between HPV16 lineages and sublineages, and the adaptation mechanism of HPV in human cells, which might facilitate HPV classification and improve vaccine development and application.

genomics↗
bioRxiv2020

Simultaneously monitoring aquatic and terrestrial biodiversity using riverine water eDNA: seasonal variation of monitoring effectiveness

Environmental DNA (eDNA) metabarcoding for biodiversity monitoring is a critical technical advance. Both aquatic and terrestrial biodiversity information can be detected in riverine water eDNA. However, it remains unverified whether riverine water eDNA can be used to simultaneously monitor aquatic and terrestrial biodiversity. Our specific objective was to assess the effectiveness of monitoring aquatic and riparian biodiversity using riverine water eDNA. We proposed that the monitoring effectiveness (the proportion of aquatic and terrestrial biodiversity information detected by riverine water eDNA samples) could be approximated by the transportation effectiveness of land-to-river and upstream-to-downstream biodiversity information flow. We conducted a case study in a watershed on the Qinghai-Tibet Plateau and estimated the effectiveness of using riverine water eDNA to monitor aquatic and riparian biodiversity based on comparing the operational taxonomic units (OTUs) and species assemblages of three taxonomic communities detected in riverine water eDNA samples and riparian soil eDNA samples in spring, summer, and autumn. The aquatic and riparian biodiversity of a watershed on the Qinghai-Tibet Plateau could be simultaneously effectively monitored using riverine water eDNA on summer or autumn rainy days. Monitoring bacterial communities was more efficient than monitoring eukaryotic communities. On summer rainy days, 43%-76% of riparian species could be detected in water eDNA samples, 92%-99% of upstream species could be detected in a 1-km downstream eDNA sample, and more than 50% of dead bioinformation (i.e., the bioinformation labeling the biological material without life activity and fertility) could be monitored 4-6 km downstream for eukaryotes and 13-19 km for bacteria. We encourage more studies on the monitoring effectiveness for each taxonomic community in other watersheds with different environmental conditions. We believe that in future ecological research, conservation and management, we could efficiently monitor and assess the aquatic and terrestrial biodiversity by simply using riverine water eDNA samples.

ecology↗
bioRxiv2018

Experimental infection characteristics of Bordetella pertussis via aerosol challenge on rhesus macaques

The effect of aerosol challenge of rhesus macaques with Bordetella pertussis and the feasibility of using rhesus monkeys as an animal model for pertussis infection were evaluated in this study. Four 1-year old rhesus macaques were aerosol challenged with B. pertussis at the concentration of 105 CFU/mL for 30 min (group 1) or 60 min (group 2). Rectal temperature was found slightly increased at days 3 and 5 and returned to baseline levels at day 21 after challenge. White blood cell counts peaked at day 7, with a 4.7~6.1-fold increase and returned to baseline levels at day 45. Bacteria colonization of nasopharyngeal swabs was observed, and the number of colonies was gradually increased and peaked at day 14, reaching 5.4-8.1 x 106/mL. The seroconversion rate of anti-pertussis toxin (PT), pertactin (PRN), and filamentous hemagglutinin(FHA) antibodies was 100%, with an increase in geometric mean titers after challenge. Analysis of cytokines revealed that the levels of cytokines including IL-2, IL-6, IL-8, IL-10, IL-17A, IL-13, IL-12, and IL-18 were significantly increased at days 5 to 14 in group 2. These results demonstrate that the characteristic of pertussis infection in infant rhesus macaque was similar as in human beings, which provide a clue to using infant rhesus macaque as a candidate model for pertussis infection in the future studies

microbiology↗