Biology subjects

Cheng, Q.

Publications and source records attributed to Cheng, Q..

At least 19 recordsLinked to original sources

bioRxiv2026

Human Gut Microbiota of Healthy Individuals Show Resilience to Acute Aflatoxin B1 Exposure Despite Solvent-Driven Community Shifts

Aflatoxin B1 (AFB1) is a potent mycotoxin linked to severe systemic health issues and gut microbiome disruption in in vivo models. However, it remains unclear whether AFB1 directly impairs human gut microbial composition and function or if observed dysbiosis is host-mediated. The objective of this work was to investigate the direct impact of acute AFB1 exposure on human gut microbiota from healthy individuals using anaerobic batch bioreactors. Fecal inoculum from 17 healthy adults was exposed to AFB1 concentrations ranging from 1,000 to 5,000 ppb, delivered in two solvents (ethanol and corn oil) under conditions simulating the large intestine. Metabolic activity was assessed via short-chain fatty acid (SCFA) and gas production measurements, while community structure was assessed using 16S rRNA gene amplicon sequencing. AFB1 concentrations remained stable throughout the incubations, indicating no significant microbial degradation of AFB1. Results showed that AFB1 did not significantly alter microbial SCFA output or community composition compared to solvent-only controls. Observed shifts in microbial profiles were primarily driven by the solvents used to bring AFB1 into solution rather than by the toxin. These findings demonstrate that healthy human gut microbial communities are resilient to direct, acute AFB1 exposure even at concentrations exceeding typical dietary levels. This suggests that microbiome disruption reported in vivo may be an indirect consequence of host-mediated factors, such as reactive metabolites or systemic immune responses, rather than direct toxicity by the parent compound.

microbiology↗

bioRxiv2026

A sunflower FLS2 guides reconstruction of recognition of a Xanthomonas flg22 escape variant across divergent FLS2 receptors

FLS2-mediated perception of the bacterial flagellin epitope flg22 is frequently compromised by pathogen sequence variation, and Val14-containing Xanthomonas flg22 variants remain unrecognized by multiple characterized expanded-recognition FLS2 homologues. Using AlphaFold 3-based structural screening of 256 natural FLS2 homologues against the flg22 epitope from Xanthomonas campestris pv. campestris (flg22Xcc), we identified sunflower HaFLS2-1 as the top structural candidate and experimentally validated its recognition through biochemical and immune-response assays. We then used ligand-proximal HaFLS2-1 residue states as a donor reference for iterative engineering of divergent FLS2 homologues from two distinct plant families, PsFLS2 and TjFLS2. Distinct recipient-specific residue solutions emerged in the two backgrounds, and representative functional variants carrying ten or fewer amino-acid substitutions acquired flg22Xcc recognition. Together, these results show that, for this defined flg22Xcc escape challenge, AF3-guided discovery and iterative local sequence exploration can reconstruct recognition across divergent FLS2 scaffolds through a limited number of receptor substitutions.

plant biology↗

bioRxiv2026

AbRefine: Framework-Conditioned Refinement for Structure-Guided Antibody CDR Design

Structure-guided antibody CDR design constrains residue selection using backbone geometry, but structural evidence alone may leave multiple amino acids plausible. We investigate whether the fixed antibody framework provides complementary sequence information for resolving this ambiguity. We introduce AbRefine, an information-aware fusion framework that combines backbone-conditioned structural predictions with framework-conditioned sequence distributions derived from a pretrained antibody language model with all designed CDRs masked. Its Information-Aware Fusion (IAF) module learns residue-specific fusion weights from the uncertainty, disagreement, and information content of the two predictive distributions, while keeping both pretrained experts frozen. Controlled interventions show that the signal is target specific: matched frameworks outperform shuffled frameworks by 7.37 percentage points, and the largest gain occurs at positions with high structural uncertainty and informative framework evidence (+5.77$ points). Compared with static fusion, IAF further improves AbMPNN recovery by +1.53 points (95\% CI +0.93$ to +2.14$) and significantly reduces native negative log-likelihood for both AbMPNN and AntiFold, without detectable degradation in fold-back structural compatibility. These results show that framework context provides information beyond backbone geometry and that learning its residue-specific utility enables effective adaptive fusion for antibody CDR design.

bioinformatics↗

bioRxiv2026

Reconsidering the Use of Dimethyl Sulfoxide for Xenobiotic-Gut Microbiota Interaction Studies

Introduction: Gut microbiota are vulnerable to foreign chemicals (xenobiotics) including pharmaceuticals, environmental pollutants, and dietary contaminants such as aflatoxin B1 (AFB1) and fumonisin B1 (FB1). Assessing the effect of these xenobiotics in the laboratory requires their dissolution in a solvent vehicle, such as dimethyl sulfoxide (DMSO). While DMSO is typically used at low concentrations under the assumption of neutrality, its independent impact on microbial dynamics is a potential experimental confounder that has not been fully explored. Methods: Human fecal microbiota were cultivated in vitro for 16 days, supplemented with 0, 10, 100, and 1000 ppb of the tested xenobiotics (AFB1 or FB1) in 0.05% DMSO (v/v), with a DMSO-free control included for comparison. Microbial community dynamics were characterized via full-length 16S rRNA gene sequencing, and metabolic activity was assessed by measuring production of short-chain fatty acids and gases. Results: DMSO significantly altered microbial metabolism and drove the consistent enrichment of Desulfovibrio desulfuricans. This shift occurred across all AFB1 and FB1 treatment groups regardless of their concentrations, indicating that the biological impact of the DMSO vehicle overshadowed the specific effects of the xenobiotics. Discussion: These findings demonstrate that DMSO can induce significant microbial shifts independent of the xenobiotics under study, potentially confounding biological interpretations. This highlights a critical need for rigorous vehicle validation and the identification of safe thresholds for solvents used in microbiota research.

microbiology↗

bioRxiv2026

Functional and evolutionary insights into the emerging tet(X4)-carrying non-O1/O139 Vibrio cholerae from retail pork

The tigecycline resistance gene tet(X4) is prevalent in Enterobacteriaceae, particularly in Escherichia coli. To our knowledge, no study has reported the dissemination dynamics of tet(X4) in Vibrio spp. Herein, we isolated and characterized a first tet(X4)-positive non-O1/O139 Vibrio cholerae isolate from retail pork. Genomic sequencing identified a novel tet(X4) variant in the V. cholerae chromosome, harboring a G568A nucleotide substitution that resulted in an Ala190Thr (A190T) amino acid substitution in Tet(X4). While this Tet(X4)-A190T variant conferred lower phenotypic resistance to tetracyclines (including tigecycline) than the wild-type Tet(X4), its overall catalytic efficiency against these antibiotics was paradoxically enhanced despite a reduced substrate affinity. Genomic comparisons revealed that two copies of ISCR2 flanked the variant gene, and the structure was ISCR2-hp-hp-abh-tet(X4)G568A -ISCR2, which is highly homologous to the reported E. coli plasmids carrying tet(X4). In addition, it confirmed the presence of an ISCR2-mediated circular intermediate, proving this modules capacity for horizontal transfer of the tet(X4)G568A variant. Furthermore, the ISCR2-tet(X4) genetic structure carrying the G568A substitution was integrated within a chimeric SXT/R391-like integrative and conjugative element (ICE), which is also serving as a vehicle for genetic dissemination. As per our knowledge, this is the first report on the emergence of SXT/R391-like ICE carrying tet(X4) in Vibrio strains. Our finding demonstrates that the clinically relevant tigecycline resistance gene tet(X4), previously confined mainly to Enterobacterales from humans and livestock, is now actively spreading into environmental Vibrio populations. This cross-species transfer highlights a previously underappreciated ecological and public health concern in aquatic ecosystems.

microbiology↗

bioRxiv2026

Phenotype-driven de novo molecular design from gene expression signatures

AO_SCPLOWBSTRACTC_SCPLOWTarget-based and structure-guided drug design remain central to modern drug discovery, but complementary strategies are needed when predefined targets or binding pockets do not fully capture disease biology. Gene-expression signatures provide scalable system-level readouts of disease and perturbation states, making them attractive inputs for phenotype-guided molecular design. However, preserving phenotypic information during molecular generation remains challenging, and chemically plausible molecules may lose connection to the intended biological response. Here, we present Tx2Mol, a transcriptome-guided framework that translates gene-expression signatures into candidate molecules while maintaining biological guidance throughout generation. We evaluated Tx2Mol across three biological settings: bulk gene perturbation, single-cell perturbation, and patient-derived disease signatures; and three validation dimensions: chemical plausibility, structural compatibility, and phenotypic preservation. Across 10 cancer-relevant bulk gene-perturbation benchmarks, Tx2Mol outperformed 9 transcriptome-guided baselines, improving maximum Tanimoto similarity to known ligands by 24.10% on average and by 50.67% on HDAC1. Structure-based analyses further supported structurally novel candidates with favorable predicted target binding. Tx2Mol also generalized to noisy single-cell perturbation profiles and preserved drug-induced transcriptional responses through in silico drug-perturbation validation. Patient-derived disease signatures further guided molecular generation toward approved-drug chemical space. Together, these results support gene-expression phenotypes as actionable guidance signals for phenotype-directed molecular design and candidate prioritization.

bioinformatics↗

bioRxiv2026

Gymnosperm FLS2 orthologues mediate conserved flg22 perception and divergent responses to flg22 variants

O_LIWhether gymnosperm FLAGELLIN-SENSING 2 (FLS2) orthologues are functional receptors and whether their flg22-recognition spectra have already diversified remain unclear, despite the central role of FLS2 in flagellin perception in angiosperms. C_LIO_LIHere, we identified two gymnosperm FLS2 orthologues, GbFLS2 from Ginkgo biloba and PtFLS2 from Pinus tabuliformis, and analysed their function using transient and stable expression in the Nicotiana benthamiana fls2 mutant, in planta cross-linking assays, AlphaFold3 modelling and structure-guided mutagenesis. C_LIO_LIBoth receptors restored flg22Pst-triggered reactive oxygen species production and MAPK activation, physically associated with flg22Pst, and required conserved residues for flg22Pst recognition. In stable transgenic plants, both receptors mediated flg22Pst-triggered PTI outputs and flg22Pst-induced resistance to Pseudomonas syringae. PtFLS2 additionally mediated responsiveness to flg22Rso and enhanced resistance to Ralstonia solanacearum, whereas GbFLS2 retained a typical flg22Pst-recognition profile. C_LIO_LIThese findings provide direct evidence that gymnosperm FLS2 orthologues can function as bona fide flagellin receptors in a heterologous angiosperm background, and further suggest that diversification in flg22 recognition had already emerged within gymnosperms. C_LI

plant biology↗

bioRxiv2026

HalluCodon enables species-specific codon optimization using multimodal language models

Codon optimization is widely used in transgenic crop development, plant synthetic biology, and molecular farming to improve heterologous protein expression in plant cells. Increasing availability of plant omics data now enables optimization strategies that account for species-specific sequence features. We developed HalluCodon, a customizable framework that uses multimodal language models to design coding sequences tailored to individual plant species. The framework allows users to fine tune pre-trained protein and RNA language models with their own datasets to build species-specific codon optimization models. The current implementation includes base models trained on coding sequences and proteomes from fifteen plant species. HalluCodon generates coding sequences through a hallucination-based design strategy guided by two predictive modules that evaluate coding sequence naturalness (CodonNAT) and expression potential (CodonEXP). Benchmark tests using representative proteins show that the generated sequences reproduce host-specific codon usage patterns and support high expression levels in plant systems.

bioinformatics↗

bioRxiv2026

PROTOTYPE-BASED CONTINUAL LEARNING FOR SINGLE-CELL ANNOTATION

Large-scale single-cell atlases provide an increasingly comprehensive view of cellular diversity, but their continued expansion across studies poses a fundamental challenge: preserving consistent cell identities while capturing biological variation in cellular states. Most existing annotation frameworks are built around static references, making it difficult to incorporate newly generated datasets into established cellular representations without retraining on historical data. When updated sequentially, these methods are further constrained by catastrophic forgetting and batch-specific biases, limiting scalability and the continuity of knowledge integration. Here we introduce scEvolver, a continual learning framework for single-cell annotation that incrementally accumulates knowledge through memory-guided refinement of cell-type prototypes without revisiting historical data. Across sequencing platforms, tissue contexts and molecular modalities, scEvolver supports robust annotation and external query mapping with substantially fewer labelled reference cells. By preserving consistent cell-type semantics across datasets while capturing biologically meaningful within-class heterogeneity, scEvolver enables the identification of epithelial cell-state transitions in inflammatory gut disease. External mapping to the healthy Human Lung Cell Atlas further reveals shared cell-state deviations across multiple diseases, including an FCGR3A+ inflammatory monocyte programme in sarcoidosis, chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, highlighting scEvolvers potential to characterize context-specific cellular dynamics in complex disease settings.

bioinformatics↗

bioRxiv2026

Malaria control and the unexpected spread of diagnostic-resistant Plasmodium falciparum in Peru

Plasmodium falciparum parasites with deletions of the histidine-rich protein 2 and 3 (hrp2 and hrp3) genes evade detection by common rapid diagnostic tests (RDTs) and pose a growing threat to malaria control. While these deletions have emerged in multiple regions globally, the evolutionary forces driving their spread remain unclear. Here, we analyze 1,215 P. falciparum samples collected between 2003 and 2018 in Loreto, Peru. This region experienced a major decline in malaria transmission following the Project for Malaria Control in Andean Border Areas (PAMAFRO) and now harbors a high proportion of hrp2/3 deleted parasites despite limited RDT use. Using molecular inversion probe (MIP) sequencing across > 2,000 genome-wide loci, we observed a marked reduction in genetic diversity, increased clonality, and fixation of parasites with deletions of both hrp2 and hrp3 genes (hrp2-/3-) over time. Identity-by-descent (IBD) analysis revealed rapid expansion of a single hrp2-/3- dominant lineage in the post-PAMAFRO period, consistent with clonal replacement after intense malaria control. Targeted sequencing of the hrp2/3 regions showed conserved deletion breakpoints across three different lineages, indicative of recombination of a common haplotype into distinct genetic backgrounds. To investigate the evolutionary forces driving the fixation of hrp2-/3- in Loreto, we simulated allele frequency trajectories under different selection coefficients. We found that fixation of hrp2-/3- due solely to genetic drift (selection coefficient s = 0) is unlikely; a selection coefficient of s [≥] 0.03 was required for fixation to occur consistently. However, our simulations also indicate that a genetic bottleneck caused by PAMAFRO increased the likelihood of fixation through drift by 4.5- to 17-fold depending on the population. These findings suggest that hrp2-/3- fixation was likely driven by a combination of demographic changes resulting from PAMAFRO and selective advantage unrelated to RDT use. Our results demonstrate how intensive malaria control efforts can reshape parasite populations and underscore the value of expanded genomic surveillance as countries move toward malaria elimination.

genetics↗

bioRxiv2026

The heat-ramp method to study regulated cell death in a pathogenic yeastCryptococcus neoformans

Human fungal pathogens cause a significant public health burden. While no reliable surveilence data are available, estimations suggest that 1 billion infections and over 2 million deaths are attributable to fungal infections annually worldwide. This drove the World Health Organization to generate a priority list of fungal pathogens for reearch, which includes the yeast Cryptococcus neoformans in a top critical priority. With the rise of drug-resistance and emerging fungal pathogens, new conceptual strategies for antifungal therapies are needed in addition to existing antibiotic development pipelines to meet clinical needs. Intrinsic cell death pathways encoded by pathogenic fungi are largely unstudied but could be leveraged for antifungal therapy analogous to anti-cancer therapeutics that activate apoptosis or other cell death mechanisms. Thus far, molecularly defined fungal cell death mechanisms are best characterized for only a few, predominantly model filamentous species. To extend these studies to pathogenic yeast, here we describe and demonstrate a tunable heat-ramp stimulus that when applied to small volumes of yeast cell suspensions reveals a protracted cell death process in the pathogenic yeast Cryptococcus neoformans. This low cost protocol induces robust and reproducible phenotypes to study gene-dependent mechanisms in laboratory strains and clinical isolates.

microbiology↗

bioRxiv2025

Resolving Local and Global Conformational Heterogeneity of the Human Intrinsically Disordered Proteome

Linking the sequences of intrinsically disordered regions (IDRs) to their structural ensembles and biological functions remains a central challenge in understanding how disorder encodes activity. A recent study has shown that human IDRs with different levels of compactness, as measured by Florys exponent, are associated with specific cellular functions and localizations, and Florys exponent can be predicted from sequence features with reasonable accuracy. However, IDRs are known to sample highly heterogenous conformations that can be masked by ensemble-averaged metrics such as Florys exponent. Here, we introduce a simple framework that resolves heterogeneous conformations. We pair two polymer physics descriptors, shape ratio (Rs) and relative shape anisotropy (RSA), to construct joint two-dimensional (RSA, Rs) maps at both the global and local (subchain) scales. We show that sequences with similar Florys exponent can display strikingly different two-dimensional conformational maps that reflect differences in charge patterning. IDRs with similar global maps can exhibit markedly different local maps that can be linked to local sequence variations. This leads to the identification of a class of IDRs that appear non-compact globally but contain locally compact subchains. These locally compact IDRs are found to be associated with similar GO functional and cellular localization enrichments and phase-separation propensities as globally compact IDRs. Our framework moves beyond ensemble-averaged descriptors, providing new tools that capture the intrinsic heterogeneity of IDR conformations and thus offer new opportunities to link IDR sequences with functions. Significance StatementIntrinsically disordered proteins (IDPs) and regions (IDRs) exhibit highly heterogeneous conformational ensembles, yet studies routinely use ensemble-averaged metrics to characterize them that obscure this heterogeneity. We present a simple, general framework that quantifies structural heterogeneity in human IDRs. This resolves forms of structural heterogeneity that are otherwise overlooked and enhances our understanding of how IDR structures relate to their sequences and functions. A python package for immediate implementation of this framework is provided.

biochemistry↗

bioRxiv2025

Sodium Aurothiomalate Induces Ferroptosis by Targeting GPX4 via Gold-Dependent Thiomalate Covalent Modification

Ferroptosis, an iron-dependent form of oxidative cell death, is predominantly regulated by glutathione peroxidase 4 (GPX4), making it a promising target for cancer therapy. However, the majority of GPX4 inhibitors, most of which contain a chloroacetamide moiety such as RSL3, are limited by poor pharmacokinetic properties and off-target effects, hindering their preclinical translation. Utilizing a range of interdisciplinary methodologies, we show that sodium aurothiomalate (ATM), a drug approved by many agencies, induces ferroptosis by covalently targeting GPX4 via formation of a selenenylsulfide bond. In preclinical models of neuroblastoma and acute myeloid leukemia (AML), ATM combined with ferric ammonium citrate (FAC) yields a synergistic effect, resulting in a significant reduction in tumor growth. Mechanistically, ATM disrupts GPX4 activity by covalently binding thiomalate to the active site selenocysteine, while modification of specific cysteine residues leads to destabilization of the protein and impaired binding to phospholipids. We propose that these covalent modifications are achieved through a unique reaction mechanism, in which the gold component of ATM acts as a thiol-masking carrier and is only transiently present, being subsequently displaced and allowing the reaction of the thiomalate moiety with the target selenocysteine or cysteine. Our data lay the foundation for development of novel, drug-like thiol-based GPX4 inhibitors.

biochemistry↗

bioRxiv2025

Light-Activated Nucleic Acid Amplification Systems Using Photo-caged DNA Polymerase or Primers

Precise control over nucleic acid amplification is essential for achieving reliable, quantitative, high-throughput, and multiplexed molecular diagnostics, particularly in point-of-care and field settings. However, conventional isothermal amplification methods, especially rapid assays at ambient temperature such as recombinase-aided amplification (RAA), suffer from spontaneous initiation and lack of synchronization across parallel reactions. Here, we report light-activatable RAA systems employing two distinct photocaging strategies to achieve spatiotemporal control. In the first, a photocaged DNA polymerase was engineered via site-specific incorporation of p-azido-L-phenylalanine and conjugation with a 2-nitrobenzyl-modified ssDNA blocker through click chemistry. This approach offers high stability, making it advantageous for long-term storage and lyophilized formats. In the second, 5'-nitrobenzyl-modified primers were synthesized to block hybridization or extension until UV activation, offering operational simplicity and rapid integration into existing workflows. Both strategies independently suppressed background activity in the dark and restored full amplification efficiency upon 365 nm UV exposure. The systems exhibited high sensitivity, low background, and compatibility with portable diagnostics. A custom-built device integrating UV activation and real-time fluorescence detection enabled seamless, on-demand operation. This modular platform provides flexible light-gated amplification solutions, allowing the selection of polymerase- or primer-based caging according to storage stability or workflow requirements, thereby advancing precise and field-ready molecular diagnostics.

molecular biology↗

bioRxiv2025

IFNγ-induced memory in human macrophages is not sustained by epigenetic changes but the durability of the cytokine itself

Macrophages, as key sentinel cells of the innate immune system, can retain memory of prior stimulus exposure. Interferon gamma (IFN{gamma}) plays a central role in maintaining trained immunity in vivo and can induce potent memory in macrophages. Such memory is associated with the formation of de novo enhancers that alter gene expression responses to subsequent stimuli. However, how such enhancers are maintained after cytokine exposure remains unclear. We report that durable IFN{gamma}-induced enhancers can last for days after cytokine washout, yet the underlying persistence mechanism is not cell-intrinsic. IFN{gamma}-treated macrophages continue to exhibit JAK/STAT signaling days after cytokine removal. Blocking IFN{gamma} signaling with a JAK inhibitor or anti-IFN{gamma} neutralizing antibodies after cytokine removal is sufficient to reverse IFN{gamma}-induced enhancers and erase the potentiated state of the treated macrophages. Our findings suggest that epigenetic changes in macrophages do not inherently encode innate immune memory or a "potentiated" macrophage state, but in fact are themselves dependent on ongoing cytokine signaling. These findings suggest new possibilities for pharmacologic interventions to reverse aberrantly trained immune states associated with pathology.

immunology↗

bioRxiv2025

Structure-based analysis unveils co-origin of LPOR and nitrogenase-like proteins

Structures of nitrogenases, dark-operative protochlorophyllide oxidoreductases, and light-dependent protochlorophyllide oxidoreductases (LPOR) have been resolved. However, their evolutionary relatedness remains elusive. Here, we show, through structural alignment, that all subunits of nitrogenase-like proteins originated from a co-ancestral archaic one-subdomain precursor. LPOR evolved from the BchX/BchY subunits of nitrogenase-like chlorophyllide a oxidoreductase (COR), and the intermediary retinol dehydrogenase through possible genetic recombination. We thus establish previously unknown structural links among key enzymes involved in biological nitrogen-fixation (BNF) and photosynthesis, unraveling structure-guided functional evolution from a single-subunit iron protein to multi-subunit nitrogenase-like COR, and to the single-subunit LPOR for phototrophic metabolism via bacteriochlorophyll, retinal, and chlorophyll. This work also demonstrates structural similarities are imperative for inferring distant origins of functionally divergent proteins, particularly those lacking primary amino-acid sequence identity. Moreover, our findings coupled with AI may be exploited to design innovative light-driven CORs and/or light-utilizing nitrogenases with enhanced efficacy of photosynthesis and BNF. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=177 SRC="FIGDIR/small/634645v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@9f9a2aorg.highwire.dtl.DTLVardef@4243ecorg.highwire.dtl.DTLVardef@796b4corg.highwire.dtl.DTLVardef@17373da_HPS_FORMAT_FIGEXP M_FIG C_FIG Video abstracthttps://www.youtube.com/watch?v=b0qBE1JMaH0 HighlightsO_LILPOR evolves from BchX and BchY subunits of the nitrogenase-like protein (NGLP) COR C_LIO_LIAll subunits of NGLPs can be traced back to the ancestral one-subdomain precursor C_LIO_LIRetinol dehydrogenase acts as a crucial intermediate in the COR to LPOR evolution C_LIO_LIStructure-based design of LUN is showcased to revolutionize protein engineering C_LI

evolutionary biology↗

bioRxiv2025

The transsulfuration pathway suppresses the embryonic lethalphenotype of glutathione reductase mutants in Caenorhabditis elegans

The gsr-1 gene encodes the only glutathione reductase in Caenorhabditis elegans and gsr-1 loss of function alleles have a fully penetrant embryonic lethal phenotype. Therefore, maintenance of glutathione redox homeostasis is essential for nematode survival. We report here that impairment of the nonsense-mediated mRNA decay (NMD) pathway suppresses the embryonic lethality of gsr-1 mutants, allowing their normal development and growth. This NMD pathway dependent suppression requires cth-1 and cth-2 that encode, respectively, two isoforms of cystathionine-{gamma}-lyase that catalyze the conversion of cystathionine to cysteine through the transsulfuration pathway. Interestingly, the thioredoxin system that can also provide cysteine through the cystine reduction pathway is not required for the suppression of the lethal phenotype of gsr-1 embryos when the NMD pathway is inactivated. Together, our data indicate that increasing the activity of the reverse transsulfuration pathway can compensate the detrimental effect of the gsr-1 mutation, raising the interesting question of why C. elegans has not preserved such compensatory mechanism to avoid the embryonic lethality of these mutants. HighlightsO_LIA novel cryptic deletion in the smg-3 gene suppresses the embryonic lethality of C. elegans gsr-1 mutants. C_LIO_LIInactivation of the nonsense-mediated mRNA decay (NMD) pathway allows survival of gsr-1 mutant worms. C_LIO_LIGenetic impairment of the transsulfuration pathway restores the embryonic lethal phenotype in gsr-1; smg-3 mutants. C_LI

genetics↗

bioRxiv2024

HumanTestisDB: A Comprehensive Atlas of Testicular Transcriptomics and Cellular Interactions

Advances in single-cell technology have enabled the detailed mapping of testicular cell transcriptomes, which is essential for understanding spermatogenesis. However, the fragmented nature of age-specific data from various literature sources has hindered comprehensive analysis. To overcome this, the Human Testis Database (HumanTestisDB) was developed, consolidating multiple human testicular sequencing datasets to address this limitation. Through extensive investigation, 38 unique cell types were identified, providing a detailed perspective on cellular variety. Furthermore, the database systematically categorizes samples into eight developmental stages, offering a structured framework to comprehend the temporal dynamics of testicular development. Each stage features comprehensive maps of cell-cell interactions, elucidating the complex communication network inside the testicular microenvironment at particular developmental stages. Moreover, by facilitating comparisons of interactions among various cell types at different stages, the database permits examining alterations that transpire during critical transitions in spermatogenesis. HumanTestisDB, available at https://shalab.njmu.edu.cn/humantestisdb, offers vital insights into testicular transcriptomics and interactions, serving as an essential resource for advancing research in reproductive biology.

cell biology↗