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Biology subjects

Wei, Y.

Publications and source records attributed to Wei, Y..

At least 73 records · Page 4Linked to original sources

Elucidating the Contribution of OVLT Glutamatergic Neurons to Mineralocorticoid Hypertension in TASK-/- Mice

BackgroundAldosterone overactivity intensifies central sodium sensitivity and sympathetic output, driving salt-sensitive hypertension, but specific mechanisms remain incompletely defined. Herein, we aimed to explore the role of organum vasculosum of the lamina terminalis glutamatergic neurons (OVLTGlut) and their hyperexcitability mechanisms in hyperaldosteronism-associated hypertension. MethodsAdult age matched male TASK-/- mice (primary aldosteronism model) and wild-type controls (TASK+/+) mice were used. Neuronal excitability was assessed via patch-clamp techniques. Arterial blood pressure (BP) monitored via telemetry or carotid catheterization. Chronic drug delivery used minipumps. RNA-seq/qPCR profiled gene expression, and intracerebroventricular hypertonic saline tested sodium sensitivity. ResultsIn TASK-/- mice, heightened OVLTGlut activity increased sympathetic outflow and hypertension, mitigated by OVLTGlut neuron ablation. Optogenetic activation of these neurons or their paraventricular nucleus (PVN) / rostral ventrolateral medulla (RVLM) projections acutely elevated BP, with ablation reducing BP selectively in TASK-/- mice. Aldosterone dependence of OVLTGlut-PVN/RVLM neuron hyperactivity was evident in both TASK-/- mice and TASK+/+ mice with chronic aldosterone infusion. Aldosterone chronic infusion enhanced central sodium pressor effects, that were nullified by OVLTGlut-PVN/RVLM neuron lesioning. RNA-seq indicated that aldosterone-induced ion channel expression spectrum changes, including potassium channels and the epithelial sodium channel, underlie the neuronal hyperexcitability. ConclusionOveractivation of OVLTGlut neurons contributes to hypertension in TASK-/- mice through regulation of OVLTGlut-PVN/RVLM circuits. The hyperexcitability of these neurons, possibly due to aldosterone-induced changes in ion channel expression spectrum, contribute to hypertension by amplifying central sodium sensitivity.

neuroscience↗

Engineering orthogonal and synergistic modules in marine bacteria for efficient upcycling of lignin-derived carbon

Reverting waste carbon into chemicals and materials with minimal freshwater reliance is essential for a sustainable future. Here, we report the establishment of a blue biological scheme by repurposing the evolutionary fitness of marine bacterium Roseovarius nubinhibens for efficient conversion of lignin-derived carbon into valuable chemicals with seawater as a water source. We created independency of the superior catalytic capacity of R. nubinhibens to circumvent a rare polar effect, and genetically decoupled the bioproduction pathway from central metabolism, channeling all lignin-derived carbon into desired products. Next, an orthogonal growth module was generated with acetate as a second carbon source, which is a ubiquitous byproduct and inhibitor in plant biomass hydrolysis, to sustain cell growth and supply necessary resources, but not substrates, for the growth-coupled bioproduction. Besides this designed metabolic segregation, we identified a cross-module push-and-pull synergy between bioproduction and cell growth, enabling enhanced performance and robustness. By deploying this biological scheme, we successfully achieved escalated conversion of the lignin-derived monomer 4-hydroxybenzoate to value-added compounds protocatechuate and {beta}-ketoadipate with seawater, rather than freshwater, as the water source, generating a distinct blue biological scheme with potentials in simultaneous carbon and water conservation.

bioengineering↗

Unveiling the hidden window of prime editing

Cleavage-dependent CRISPR-Cas gene editing relies on RNA-guided DNA cleavages that push cellular machinery to incorporate intended edits. Yet, a second cleavage on the already cut DNA strand can also be executed by CRISPR nucleases. This feature, however, has never been repurposed for gene editing. Here, we report the first integration of the second cleavage activity of Cas9 for precision gene editing, allowing previously impossible prime editing in the 5 direction of a nick. We elucidate the second-cleavage-driven pathway that primes non-canonical reverse transcription events upstream of the nick. We identify the competition between the non-canonical and canonical routes, which can be modulated by rationally designing RNA templates with intended edits. We demonstrate that cellular physiologies elevate editing efficiency from individual reverse-transcripts yet exert limited influence on the pathway competitions. Our findings reshape the design principle of prime editing and open an entirely new dimension for engineering CRISPR-Cas systems with the intrinsic, non-host-specific second cleavage activity.

synthetic biology↗

A Reductive Uric Acid Degradation Pathway in Anaerobic Bacteria

Uric acid is a key intermediate in purine degradation across diverse organisms, while its accumulation in humans leads to inflammation and gout disease. Aerobic organisms degrade uric acid via a well-known "oxidative pathway" involving dearomatization of the purine core catalyzed by uric acid oxidases or dehydrogenases. The ability to degrade uric acid is also widespread in anaerobic bacteria, including gut bacteria, although the mechanisms are incompletely understood. Here, we report the biochemical characterization of a recently identified uric acid degradation gene cluster from Escherichia coli, and show that it encodes a "reductive pathway" for uric acid degradation. In this pathway, uric acid is first reduced to isoxanthine (2,8-dioxopurine) by a xanthine dehydrogenase homolog (XdhD), followed by dearomatization of the purine core catalyzed by a flavin-dependent reductase (YgfK). Stepwise cleavage of the pyrimidine and imidazole rings forms 2,3-diureidopropionate, and stepwise cleavage of the 2- and 3-ureido groups then forms 2,3-diaminopropionate, which is cleaved by a pyridoxal 5-phosphate-dependent lyase (YgeX) to pyruvate and ammonia. Detection of isoxanthine in clinical serum samples suggests it is a physiologically relevant circulating metabolite. A probiotic E coli Nissle strain was engineered for constitutive overexpression of the gene cluster, and oral administration in a uricase-knockout hyperuricemic mouse model significantly reduced the serum uric acid level and alleviated associated kidney injury, suggesting a potential route towards uricolytic probiotics.

biochemistry↗

Single-cell analyses reveal scyphozoan conserved and specific genes contribution during tissue regeneration in two jellyfish

The phylum Cnidaria is the outgroup of Bilateria and includes sea anemones, corals, hydroids, and jellyfish. Cnidarians play crucial ecological roles in marine ecosystems, including the formation of highly diverse and productive coral reefs, and acting as important predator and prey species. Cnidarians are also well known for their remarkable regeneration capacities. Here, we report single-cell RNA sequencing during bell regeneration in two species of scyphozoans or true jellyfish, Aurelia coerulea and Rhopilema esculentum. We delineated 12 cell populations in Aurelia and Rhopilema, and revealed their respective marker genes and enriched gene pathways. Conserved transcription factor Otx and Wnt/ {beta}-catenin signalling pathway genes were identified during regeneration processes. Additionally, we discovered two conserved, sequentially activated modules during regeneration, with stem cells, gastrodermal cells, neural cells, and secretory gland cells modulated in the first phase, followed by cnidocytes in the second phase. Further comparison among cnidarian genomes identified a suite of scyphozoan lineage-specific genes, a subset of which were frequently significantly expressed in cnidocytes in both jellyfish species during the first phase of regeneration. This study reveals key insights into the evolution and contribution of conserved and novel genes to the formation of lineage-specific genetic networks and biological processes.

evolutionary biology↗

Niche Macrophages Recycle Iron to Tumor Cells and Foster Erythroblast Mimicry to Promote Bone Metastasis and Anemia

Bone marrow is both a primary site for blood cell production and a fertile niche for metastatic cancer cell growth, notably in breast cancer. Although anemia is common among patients with bone metastasis, the mechanistic link between metastatic colonization and disrupted erythropoiesis remains poorly understood. Using in vivo niche labeling and single-cell RNA sequencing, we identified a specialized population of VCAM1+CD163+CCR3+ macrophages enriched in the bone metastatic niche. These macrophages, typically essential for erythropoiesis in healthy bone marrow, are co- opted by tumor cells to support their growth through iron acquisition. The hijacking of these macrophages by tumor cells reduces iron availability for erythroblasts, impairing erythropoiesis and contributing to anemia. With increased iron supply, tumor cells further adapt by mimicking erythroblasts, producing hemoglobin under GATA1 regulation in response to hypoxic stress. Notably, macrophages with similar iron- regulating features were found in human bone metastases across multiple cancer types, and elevated HBB expression in breast cancer correlates with increased risk of bone metastasis. These findings establish iron-recycling macrophages as essential regulators within the metastatic bone niche, revealing novel insights into the interplay between immune modulation, metal metabolism and tumor cell plasticity in driving metastatic progression and anemia.

cancer biology↗

Allo-PED: Leveraging protein language models and structure features for allosteric site prediction

Allosteric regulation plays a pivotal role in modulating protein function and allosteric sites represent a promising target for drug discovery. However, identifying allosteric sites remains challenging due to their structural and evolutionary diversity. Here, we present AlloPED, a novel framework that combines protein language models and machine learning to predict allosteric sites with high accuracy. AlloPED consists of two modules: AlloPED-pocket, an ensemble model leveraging physicochemical features to predict allosteric pockets; and AlloPED-site, a dilated convolutional neural network (DCNN) augmented with a comprehensive attention mechanism for residue-level prediction. AlloPED-pocket achieves state-of-the-art performance on benchmark datasets, yielding an MCC of 0.544 and an AUC of 0.920, outperforming existing methods such as AllositePro and PARS. AlloPED-site further refines predictions using high-dimensional sequence embeddings from the ProtT5 protein language model, achieving a precision of 0.601, a recall of 0.422, and a specificity of 0.661. These results highlight the effectiveness of integrating ensemble learning and deep learning for allosteric site prediction. AlloPED also identifies critical determinants of allosteric sites, including residue clustering coefficients, van der Waals volume, and hydrophobic microenvironments. In summary, this framework provides a robust tool for advancing our understanding of allosteric regulation and facilitating structure-based drug design.

bioinformatics↗

Lack of consistent effect of dietary fiber on immune checkpoint blockade efficacy across diverse murine tumor models

Immune checkpoint blockade (ICB) has transformed cancer treatment, but success rates remain low in most cancers. Recent research suggest that dietary fiber enhances ICB response in melanoma patients and murine preclinical models through microbiome-dependent mechanisms. Yet, the robustness of this effect across cancer types and dietary contexts remains unclear. Specifically, prior literature compared grain-based chow (high fiber) to low-fiber purified diet, but these diets differ also on other dimensions including phytochemicals. Here we investigated, in mice fed grain-based chow or purified diets with differing quantities of isolated fibers (cellulose and inulin), metabolite levels and ICB activity in multiple tumor models. The blood and fecal metabolome were relatively similar between mice fed high- and low-fiber purified diets, but differed massively between mice fed purified diets or chow, identifying the factor as diet type, independent of fiber. Tumor growth studies in three implantable and two spontaneous genetically engineered tumor models revealed that fiber has a weaker impact on ICB (anti-PD-1) efficacy than previously reported. In some models, dietary modulation impacted ICB activity, but not in a consistent direction across models. In none of the models did we observe the pattern expected if fiber controlled ICB efficacy: strong efficacy in both chow and high-fiber purified diet but low efficacy in low-fiber purified diet. Thus, dietary fiber appears to have limited or inconsistent effect on ICB efficacy in mouse models, and other dietary factors that correlate with fiber intake may underlie the clinical correlations between fiber consumption and immunotherapy outcomes.

cancer biology↗

Chimera: Ultrafast and Memory-efficient Database Construction for High-Accuracy Taxonomic Classification in the Age of Expanding Genomic Data

The rapid growth of genomic data expands species diversity but also causes taxonomic imbalance, with certain species heavily overrepresented. Both data volume and imbalance challenge the accuracy and efficiency of metagenomic tools. Here, we present Chimera, a transformative tool harnessing the Interleaved Merged Cuckoo Filter (IMCF) and FairMin-Cap (FMC) strategy for next-level performance. It achieves the highest classification accuracy while providing an astonishing 162-fold faster database assembly than Kraken2, constructing the complete RefSeq genome database within mere minutes using under 32 GB of RAM, enabling rapid and cost-effective database updates. Furthermore, Chimeras universal memory scalability supports at least 300,000 species and potentially over 800,000 species in practical 1 TB systems, overwhelming traditional software solutions. Our results establish Chimera as a foundational tool for the next era of metagenomic research, laying a crucial cornerstone for the future of ultramassive genome datasets.

bioinformatics↗

A rapid and efficient red-light-activated Cre recombinase system for genome engineering in mammalian cells and transgenic mice

The Cre-loxP recombination system enables precise genome engineering; however, existing photoactivatable Cre tools suffer from several limitations, including low DNA recombination efficiency, background activation, slow activation kinetics, and poor tissue penetration. Here, we present REDMAPCre, a red-light-controlled split-Cre system based on the {Delta}PhyA/FHY1 interaction. REDMAPCre enables rapid activation (1-second illumination) and achieves an 85-fold increase in recombination efficiency. We demonstrate its efficient regulation of DNA recombination in mammalian cells and mice, as well as its compatibility with other inducible recombinase systems for Boolean logic-gated DNA recombination. Using a single-vector adeno-associated virus (AAV) delivery system, we successfully induced REDMAPCre-mediated DNA recombination in mice. Furthermore, we generated a REDMAPCre transgenic mouse line and validated its efficient, light-dependent recombination across multiple organs. To explore its functional applications, REDMAPCre transgenic mice were crossed with the relative Cre-dependent reporter mice, enabling optogenetic induction of insulin resistance and hepatic lipid accumulation via Cre-dependent overexpression of ubiquitin-like with PHD and ring finger domains 1 (UHRF1), as well as targeted cell ablation through diphtheria toxin fragment A (DTA) expression. Collectively, REDMAPCre provides a powerful tool for achieving remote control of recombination and facilitating functional genetic studies in living systems.

synthetic biology↗

RAB23 Modulates Signaling Protein Ciliary Homeostasis through Promoting RAB18-mediated Inward BBSome Transition Zone Passage

As an intraflagellar transport (IFT) cargo adaptor, the BBSome targets the basal body region located just below the transition zone (TZ) before proceeding to cross the TZ for ciliary entry. This process of TZ crossing crucially governs BBSome presence and quantity available for signaling protein coupling within cilia, influencing the dynamic behavior of signaling proteins in cilia by controlling their ciliary removal. Our previous study revealed that the GTPase RAB18 binds to its BBSome effector in the basal bodies right below the TZ and recruits the BBSome to cross the TZ for ciliary entry by lateral transport between the plasma and ciliary membranes. However, the mechanism by which RAB18 is activated to accomplish this function has remained elusive. This study uncovers that, under physiological conditions, Chlamydomonas RAB23 in its GDP-bound state (RAB23-GDP) predominantly localizes to the same basal body region as RAB18-GDP and activates RAB18-GDP as a RAB18-specific guanine nucleotide exchange factor. RAB18-GDP attaches to the membrane and binds to the BBSome. This interaction occurs independently of anterograde IFT association, allowing the BBSome to diffuse through the TZ and enter cilia. Subsequently, RAB23-GDP facilitates its own ciliary entry by binding to the RAB18-GTP/BBSome entity as a BBSome cargo. Our findings establish a model where the BBSome enters cilia through the RAB23-RAB18 module-mediated inward BBSome TZ diffusion pathway. According to this model, hedgehog signaling defects caused by rab23 mutations could induce Carpenter syndrome in humans, providing a mechanistic understanding behind the inward BBSome TZ passage required for proper ciliary signaling. Significance statementCertain ciliary signaling proteins are removed from cilia through the outward BBSome transition zone (TZ) diffusion pathway. The inward BBSome TZ crossing is orchestrated by RAB18. The current study unveils that RAB23 in its GDP-bound state (RAB23-GDP) and RAB18-GDP predominantly localize to the same basal body region located just below the TZ. RAB23-GDP activates RAB18-GDP as a RAB18-specific guanine nucleotide exchange factor. RAB18-GTP subsequently recruits the BBSome as its effector to cross the TZ for ciliary entry. Following this, RAB23-GDP enters cilia as a BBSome cargo. The regulatory interplay between RAB23 and RAB18, with RAB23 promoting inward BBSome TZ crossing via RAB18, establishes a molecular mechanism for the BBSome-dependent retrieval of signaling proteins from cilia.

cell biology↗

Unraveling the mechanism of 1-deoxynojirimycin (DNJ) accumulation: the role of SWEET3 in mulberry chloroplasts

Transporters are crucial for the accumulation and secretion of plant metabolic products. 1-Deoxynojirimycin (DNJ), a natural compound widely distributed in nature and known for its medicinal properties, has production limitations in microorganisms and herbaceous plants. Mulberry leaves, being easy to harvest and growing rapidly, are the main source of DNJ. However, the current production from mulberry is insufficient to meet the demand. Improving DNJ content in mulberry and thereby reducing production costs is a significant challenge. We first used a green fluorescent tag to visualize the localization of DNJ and found that DNJ highly accumulates in the chloroplasts of mulberry leaves but not in callus tissue. The sugar transporter gene SWEET3, which is highly expressed in mulberry leaves but not in callus, was shown to have DNJ transport capability. Molecular docking analysis revealed that the acidic amino acid residues E68 and D126 in the SWEET3 protein are potential binding sites for DNJ, and both neutral and basic mutations at these sites significantly reduced the ability to DNJ-transporting ability of SWEET3. Furthermore, transient overexpression or RNA interference of SWEET3 in mulberry leaves significantly increased or decreased DNJ content, respectively. Similarly, stable overexpression of the SWEET3 in mulberry hairy roots led to an enhancement in DNJ content within the roots. Our results demonstrated that SWEET3 is essential for DNJ accumulation in mulberry. The study represents a breakthrough in increasing DNJ yield in mulberry through the key role of transporters and identify specific molecular targets required for developing mulberry germplasm with increased DNJ levels.

plant biology↗

RAB18 Orchestrates Signaling Protein Ciliary Homeostasis by Facilitating BBSome Diffusion through the Transition Zone for Ciliary Entry

The BBSome acts as an intraflagellar transport (IFT) cargo adaptor that connects transmembrane and membrane-anchored signaling proteins to the process of IFT within cilia. This function is critical for ciliary homeostasis maintenance of signaling proteins, allowing for successfully sensing and transducing extracellular stimuli inside the cell. It is established that, upon reaching the proximal ciliary region just above the transition zone (TZ), a diffusion barrier, via retrograde IFT, the BBSome, carrying signaling proteins, disengages from IFT and diffuses through the TZ for ciliary retrieval. This TZ passage event is promoted by the Arf-like 3 GTPase, which utilizes the BBSome autonomously of IFT association as its major effector. While it is known that the intact BBSome is recruited to the basal bodies before entering cilia, the precise mechanism by which it crosses the TZ to access cilia remains elusive. In our study on Chlamydomonas reinhardtii, we disclose that the Ras-associated binding (Rab) GTPase RAB18 is concentrated in a basal body region that overlaps with the BBSome. Positioned at this location, RAB18 in a GTP-bound state (RAB18-GTP) is anchored to the membrane, allowing it to diffuse into cilia. Throughout this process, the BBSome functions as a RAB18 effector, binding to RAB18-GTP and subsequently being recruited to diffuse through the TZ for ciliary entry in an IFT-independent manner. This collaboration between the BBSome and RAB18 is pivotal in maintaining the signaling protein phospholipase D ciliary homeostasis, providing a precise mechanistic understanding of the inward BBSome TZ passage essential for proper ciliary signaling. Significance statementAlthough certain ciliary signaling proteins cross the transition zone (TZ) for ciliary removal via the RABL2-ARL3 module-mediated outward BBSome TZ diffusion pathway, how the BBSome passes the TZ for ciliary entry remains unclear. Here, we show that RAB18, in its GTP-bound state, anchors to the membrane at the basal bodies. As a RAB18 effector, the BBSome is recruited to cross the TZ for ciliary entry via lateral transport between plasma and ciliary membranes. Once inside cilia, the BBSome integrates into anterograde IFT trains and subsequently functions as a phospholipase D (PLD) adaptor, ensuring PLD removal from cilia. This study highlights RAB18s pivotal role in facilitating BBSome entry into cilia, unveiling a regulatory mechanism crucial for maintaining ciliary signaling protein homeostasis.

cell biology↗

CDP-DAG synthases regulate plant growth and broad-spectrum disease resistance

Phosphatidic acid (PA) functions as a cell membrane component and signaling molecule in plants. PA metabolism has multiple routes, in one of which PA is converted into cytidine diphosphate diacylglycerol (CDP-DAG) by CDP-DAG synthases (CDSs). CDS genes are highly conserved in plants. Here, we found that knock-down of the CDS gene enhanced the resistance of Arabidopsis thaliana to multiple pathogens, with a growth penalty. When Arabidopsis leaves were treated with chitin or flg22, reactive oxygen species (ROS) production in cds mutants was significantly higher than that in the wild-type (WT). Similarly, phosphorylation of mitogen-activated protein kinases (MAPKs) in the cds1cds2 double mutant was significantly increased compared to the WT. By integrating lipidomics, transcriptomics, and metabolomics data, PA accumulation was observed in mutants cds1cds2, activating the jasmonic acid (JA) and salicylic acid (SA) signaling pathway, and increasing transcript levels of plant defense-related genes. Significant accumulation of the downstream metabolites including serotonin and 5-methoxyindole was also found, which plays important roles in plant immunity. In conclusion, our study indicated the role of CDSs in broad-spectrum disease resistance in Arabidopsis and that CDSs are involved in plant metabolic regulation.

plant biology↗

Single-Cell Genomics Elucidates Molecular Variations and Regulatory Mechanisms in Circulating Immune Cells

The human peripheral blood displays diverse molecular characteristics across populations, understanding the drivers and underlying mechanisms of which remains challenging. Here, we introduce the Chinese Immune Multi-Omics Atlas (CIMA), elucidating sex-, age-, and genetic-related molecular variations by analyzing multi-omics data from 428 adults with over 10 million immune cells. CIMA generated an enhancer-driven gene regulatory network, identifying 237 high-quality regulons and revealing cell type-specific regulatory mechanisms. Additionally, 11,521 lead cis-expression quantitative trait loci (eQTLs) and 46,339 chromatin accessibility QTLs (caQTLs) were identified at cell type level. CIMA also uncovered pleiotropic associations among immune-related disease risk loci, eQTLs, and caQTLs in a cell type-specific manner. Lastly, a novel cell language model, CIMA-CLM, was developed to predict chromatin accessibility and noncoding variant effects using chromatin sequences and gene expressions. This work represents a population-scale multi-omics resource of human immune cells, providing a valuable reference for future investigation of immune-related diseases.

immunology↗

Single-cell spatial transcriptome reveals pathological features of human hippocampus with sclerosis

More than half of epileptic patients ultimately turned to intractable epilepsy. Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), the most common type of intractable epilepsies, whose pathological mechanism remains elusive. Here, using 42 human hippocampal samples from surgical donors of MTLE (32 with and 10 without HS) through single-cell resolution Stereo-seq and histologcial experiments, we revealed spatially pathological changes of gene expression and cell type composition with HS systematically. After precise parcellation of hippocampal subregions and differentially expressed gene (DEG) analysis between each region with and without sclerosis, we found Cornu Ammonis (CA) subregions with higher number of DEGs were vulnerable to sclerosis, especially CA1 and CA3. Within CA1, we found that CA1-superficial and proximal areas were more vulnerable than CA1-deep and distal areas in sclerosis. Meanwhile, after analyzing 350,795 segmented cells from Stereo-seq, we found dramatically increasing density of astrocyte accompanied with significantly decreasing density of excitatory neurons in CA1, especially superficial and proximal CA1, and CA3 in sclerosis. In these two vulnerable subregions, proliferative astrocyte (P_astrocyte) and reactive astrocyte (R_astrocyte) were found to be enriched whereas apoptotic subtype of astrocyte (A_astrocyte), related with apoptotic pathway, was mainly located in alveus, which strengthened cell communication with reactive microglia (R_microglia) in HS, revealing the novel pathological feature in our work. The pseudotime analysis indicated that CA excitatory neurons underwent synaptic impairment, energy dysfunction, aging, and finally losing cell identity until death through autophagy or apoptosis. Besides, we also found a resilient subtype, EX_CA2-4.3, highly expressed extracellular matrix related genes including PDYN, and was increasing the interaction of BDNF-NTRK, NFASC-CNTN1 to withstand the damage from sclerosis. Together, our study provided a reference of human hippocampus with and without HS caused by MTLE, and highlighted the potential pathological mechanism on molecular and cellular level of MTLE-HS.

neuroscience↗

Spacer Extension Reconciles Specificity and Activity in High-Fidelity Cas9 Genome Editing

AbstractEngineering high-fidelity CRISPR enzymes often leads to reduced cleavage activity, creating a significant hurdle in balancing nuclease specificity and efficiency for clinical applications. Here, we demonstrate that extending the spacer to 21 or 22 nucleotides restores the impaired cleavage activity of SuperFi-Cas9, an engineered high-fidelity Cas9 variant with seven mutations at the PAM-distal region. Structural and mutational analyses reveal that the spacer extension strengthens additional interactions at the PAM-distal end, stabilizing the nuclease- sgRNA-DNA complex, which appears to be disturbed due to the seven mutations. This approach not only provides a high-fidelity Cas9 with uncompromised efficiency but also introduces a novel strategy to enhance CRISPR complex stability. Our findings offer a promising avenue for precise and efficient genome editing, crucial for advancing CRISPR technologies toward clinical translation.

genomics↗

CRISPR/Cas9-mediated germline mutagenesis in the subsocial parasitoid wasp, Sclerodermus guani

The ectoparasitoid wasp Sclerodermus guani (Hymenoptera: Bethylidae), as a subsocial insect, is widely applied in biological control against beetle vectors of pine wood nematodes. Despite significant advances in behavioral research, functional genetics in S. guani remains underdeveloped due to the absence of efficient gene manipulation tools. In this study, we employed CRISPR-mediated mutagenesis to achieve germline gene knockout targeting the eye pigment associated gene kynurenine 3-monooxygenase (KMO). Phylogenetic analysis revealed that S. guani KMO shares a close relationship with its homolog in Prorops nasuta (Hymenoptera: Bethylidae). Two single-guide RNAs (sgRNAs), coupled with Cas9 protein with and without nuclear localization signal (NLS) were tested. Both sgRNAs induced specific in vitro DNA cleavage and in vivo heritable indels at the target genomic loci. Homozygous null mutant females and males exhibit a white-eye phenotype, which was identified during pupal stage. Optimal editing efficiency in vivo was achieved using the Cas9-NLS variant. Given the complication of germline gene editing in eusocial Hymenopterans, the application of CRISPR in the subsocial parasitoid wasp S. guani provides an accessible research platform for the molecular evolution of insect sociality.

molecular biology↗