Complexity of avian evolution revealed by family-level genomes.

Despite tremendous efforts in the past decades, relationships among main avian lineages remain heavily debated without a clear resolution. Discrepancies have been attributed to diversity of species sampled, phylogenetic method and the choice of genomic regions1-3. Here we address these issues by analysing the genomes of 363 bird species4 (218 taxonomic families, 92% of total). Using intergenic regions and coalescent methods, we present a well-supported tree but also a marked degree of discordance. The tree confirms that Neoaves experienced rapid radiation at or near the Cretaceous-Palaeogene boundary. Sufficient loci rather than extensive taxon sampling were more effective in resolving difficult nodes. Remaining recalcitrant nodes involve species that are a challenge to model due to either extreme DNA composition, variable substitution rates, incomplete lineage sorting or complex evolutionary events such as ancient hybridization. Assessment of the effects of different genomic partitions showed high heterogeneity across the genome. We discovered sharp increases in effective population size, substitution rates and relative brain size following the Cretaceous-Palaeogene extinction event, supporting the hypothesis that emerging ecological opportunities catalysed the diversification of modern birds. The resulting phylogenetic estimate offers fresh insights into the rapid radiation of modern birds and provides a taxon-rich backbone tree for future comparative studies.

Structure and mechanism of a eukaryotic ceramide synthase complex.

Ceramide synthases (CerS) catalyze ceramide formation via N-acylation of a sphingoid base with a fatty acyl-CoA and are attractive drug targets for treating numerous metabolic diseases and cancers. Here, we present the cryo-EM structure of a yeast CerS complex, consisting of a catalytic Lac1 subunit and a regulatory Lip1 subunit, in complex with C26-CoA substrate. The CerS holoenzyme exists as a dimer of Lac1-Lip1 heterodimers. Lac1 contains a hydrophilic reaction chamber and a hydrophobic tunnel for binding the CoA moiety and C26-acyl chain of C26-CoA, respectively. Lip1 interacts with both the transmembrane region and the last luminal loop of Lac1 to maintain the proper acyl chain binding tunnel. A lateral opening on Lac1 serves as a potential entrance for the sphingoid base substrate. Our findings provide a template for understanding the working mechanism of eukaryotic ceramide synthases and may facilitate the development of therapeutic CerS modulators.

A region of suppressed recombination misleads neoavian phylogenomics.

Genomes are typically mosaics of regions with different evolutionary histories. When speciation events are closely spaced in time, recombination makes the regions sharing the same history small, and the evolutionary history changes rapidly as we move along the genome. When examining rapid radiations such as the early diversification of Neoaves 66 Mya, typically no consistent history is observed across segments exceeding kilobases of the genome. Here, we report an exception. We found that a 21-Mb region in avian genomes, mapped to chicken chromosome 4, shows an extremely strong and discordance-free signal for a history different from that of the inferred species tree. Such a strong discordance-free signal, indicative of suppressed recombination across many millions of base pairs, is not observed elsewhere in the genome for any deep avian relationships. Although long regions with suppressed recombination have been documented in recently diverged species, our results pertain to relationships dating circa 65 Mya. We provide evidence that this strong signal may be due to an ancient rearrangement that blocked recombination and remained polymorphic for several million years prior to fixation. We show that the presence of this region has misled previous phylogenomic efforts with lower taxon sampling, showing the interplay between taxon and locus sampling. We predict that similar ancient rearrangements may confound phylogenetic analyses in other clades, pointing to a need for new analytical models that incorporate the possibility of such events.

Comprehensive isoform-level analysis reveals the contribution of alternative isoforms to venom evolution and repertoire diversity.

Animal venom systems have emerged as valuable models for investigating how novel polygenic phenotypes may arise from gene evolution by varying molecular mechanisms. However, a significant portion of venom genes produce alternative mRNA isoforms that have not been extensively characterized, hindering a comprehensive understanding of venom biology. In this study, we present a full-length isoform-level profiling workflow integrating multiple RNA sequencing technologies, allowing us to reconstruct a high-resolution transcriptome landscape of venom genes in the parasitoid wasp Pteromalus puparum Our findings demonstrate that more than half of the venom genes generate multiple isoforms within the venom gland. Through mass spectrometry analysis, we confirm that alternative splicing contributes to the diversity of venom proteins, acting as a mechanism for expanding the venom repertoire. Notably, we identified seven venom genes that exhibit distinct isoform usages between the venom gland and other tissues. Furthermore, evolutionary analyses of venom serpin3 and orcokinin further reveal that the co-option of an ancient isoform and a newly evolved isoform, respectively, contributes to venom recruitment, providing valuable insights into the genetic mechanisms driving venom evolution in parasitoid wasps. Overall, our study presents a comprehensive investigation of venom genes at the isoform level, significantly advancing our understanding of alternative isoforms in venom diversity and evolution and setting the stage for further in-depth research on venoms.

Progressive Cactus is a multiple-genome aligner for the thousand-genome era.

New genome assemblies have been arriving at a rapidly increasing pace, thanks to decreases in sequencing costs and improvements in third-generation sequencing technologies1-3. For example, the number of vertebrate genome assemblies currently in the NCBI (National Center for Biotechnology Information) database4 increased by more than 50% to 1,485 assemblies in the year from July 2018 to July 2019. In addition to this influx of assemblies from different species, new human de novo assemblies5 are being produced, which enable the analysis of not only small polymorphisms, but also complex, large-scale structural differences between human individuals and haplotypes. This coming era and its unprecedented amount of data offer the opportunity to uncover many insights into genome evolution but also present challenges in how to adapt current analysis methods to meet the increased scale. Cactus6, a reference-free multiple genome alignment program, has been shown to be highly accurate, but the existing implementation scales poorly with increasing numbers of genomes, and struggles in regions of highly duplicated sequences. Here we describe progressive extensions to Cactus to create Progressive Cactus, which enables the reference-free alignment of tens to thousands of large vertebrate genomes while maintaining high alignment quality. We describe results from an alignment of more than 600 amniote genomes, which is to our knowledge the largest multiple vertebrate genome alignment created so far.

Dense sampling of bird diversity increases power of comparative genomics.

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1-4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species.

Disrupted phase behavior of FUS underlies poly-PR-induced DNA damage in amyotrophic lateral sclerosis.

GGGGCC (G4C2) hexanucleotide repeat expansion (HRE) in the first intron of the chromosome 9 open reading frame 72 (C9ORF72) gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Among the five dipeptide repeat proteins translated from G4C2 HRE, arginine-rich poly-PR (proline:arginine) is extremely toxic. However, the molecular mechanism responsible for poly-PR-induced cell toxicity remains incompletely understood. Here, we found that poly-PR overexpression triggers severe DNA damage in cultured cells, primary cortical neurons, and the motor cortex of a poly-PR transgenic mouse model. Interestingly, we identified a linkage between poly-PR and RNA-binding protein fused in sarcoma (FUS), another ALS-related gene product associated with DNA repair. Poly-PR interacts with FUS both in vitro and in vivo, phase separates with FUS in a poly-PR concentration-dependent manner, and impairs the fluidity of FUS droplets in vitro and in cells. Moreover, poly-PR impedes the recruitment of FUS and its downstream protein XRCC1 to DNA damage foci after microirradiation. Importantly, overexpression of FUS significantly decreased the level of DNA damage and dramatically reduced poly-PR-induced cell death. Our data suggest the severe DNA damage caused by poly-PR and highlight the interconnection between poly-PR and FUS, enlightening the potential therapeutic role of FUS in alleviating poly-PR-induced cell toxicity.

DeepAlgPro: an interpretable deep neural network model for predicting allergenic proteins.

Allergies have become an emerging public health problem worldwide. The most effective way to prevent allergies is to find the causative allergen at the source and avoid re-exposure. However, most of the current computational methods used to identify allergens were based on homology or conventional machine learning methods, which were inefficient and still had room to be improved for the detection of allergens with low homology. In addition, few methods based on deep learning were reported, although deep learning has been successfully applied to several tasks in protein sequence analysis. In the present work, a deep neural network-based model, called DeepAlgPro, was proposed to identify allergens. We showed its great accuracy and applicability to large-scale forecasts by comparing it to other available tools. Additionally, we used ablation experiments to demonstrate the critical importance of the convolutional module in our model. Moreover, further analyses showed that epitope features contributed to model decision-making, thus improving the model's interpretability. Finally, we found that DeepAlgPro was capable of detecting potential new allergens. Overall, DeepAlgPro can serve as powerful software for identifying allergens.

A serpin gene from a parasitoid wasp disrupts host immunity and exhibits adaptive alternative splicing.

Alternative splicing (AS) is a major source of protein diversity in eukaryotes, but less is known about its evolution compared to gene duplication (GD). How AS and GD interact is also largely understudied. By constructing the evolutionary trajectory of the serpin gene PpSerpin-1 (Pteromalus puparum serpin 1) in parasitoids and other insects, we found that both AS and GD jointly contribute to serpin protein diversity. These two processes are negatively correlated and show divergent features in both protein and regulatory sequences. Parasitoid wasps exhibit higher numbers of serpin protein/domains than nonparasitoids, resulting from more GD but less AS in parasitoids. The potential roles of AS and GD in the evolution of parasitoid host-effector genes are discussed. Furthermore, we find that PpSerpin-1 shows an exon expansion of AS compared to other parasitoids, and that several isoforms are involved in the wasp immune response, have been recruited to both wasp venom and larval saliva, and suppress host immunity. Overall, our study provides an example of how a parasitoid serpin gene adapts to parasitism through AS, and sheds light on the differential features of AS and GD in the evolution of insect serpins and their associations with the parasitic life strategy.

Standards recommendations for the Earth BioGenome Project.

A global international initiative, such as the Earth BioGenome Project (EBP), requires both agreement and coordination on standards to ensure that the collective effort generates rapid progress toward its goals. To this end, the EBP initiated five technical standards committees comprising volunteer members from the global genomics scientific community: Sample Collection and Processing, Sequencing and Assembly, Annotation, Analysis, and IT and Informatics. The current versions of the resulting standards documents are available on the EBP website, with the recognition that opportunities, technologies, and challenges may improve or change in the future, requiring flexibility for the EBP to meet its goals. Here, we describe some highlights from the proposed standards, and areas where additional challenges will need to be met.

Two Novel Variants of the CAPN3 Gene in Chinese Patients with Limb-Girdle Muscular Dystrophy Recessive 1.

INTRODUCTION: Recessive mutations in the CAPN3 gene can lead to limb-girdle muscular dystrophy recessive 1 (LGMD R1). Targeted next-generation sequencing facilitates the discovery of new mutations linked with disease, owing to its ability to selectively enrich specific genomic regions. METHODS: We performed targeted next-generation sequencing of all exons of the CAPN3 gene in 4 patients with sporadic limb-girdle muscular dystrophy (LGMD) and further analyzed the effects of the novel identified variant using various software tools. RESULTS: We found 5 variants in CAPN3 gene in 4 patients, c.82_83insC (insertion mutation) and c.1115+2T>C (splicing mutation) are reported for the first time in CAPN3 (NM_000070.2). The bioinformatics analysis indicated that these two novel variants affected CAPN3 transcription as well as translation. DISCUSSION: Our findings reveal previously unreported splicing mutation and insertion mutation in CAPN3 gene, further expanding the pathogenic gene profile of LGMD.

Host and venom evolution in parasitoid wasps: does independently adapting to the same host shape the evolution of the venom gland transcriptome?

BACKGROUND: Venoms have repeatedly evolved over 100 occasions throughout the animal tree of life, making them excellent systems for exploring convergent evolutionary novelty. Growing evidence supports that venom evolution is predominantly driven by prey or host-related selection pressures, and the expression patterns of venom glands reflect adaptive evolution. However, it remains elusive whether the evolution of expression patterns in venom glands is likewise a convergent evolution driven by their prey/host species. RESULTS: We utilized parasitoid wasps that had independently adapted to Drosophila hosts as models to investigate the convergent evolution of venom gland transcriptomes in 19 hymenopteran species spanning ~ 200 million years of evolution. Comparative transcriptome analysis reveals that the global expression patterns among the venom glands of Drosophila parasitoid wasps do not achieve higher similarity compared to non-Drosophila parasitoid wasps. Further evolutionary analyses of expression patterns at the single gene, orthogroup, and Gene Ontology (GO) term levels indicate that some orthogroups/GO terms show correlation with the Drosophila parasitoid wasps. However, these groups rarely include genes highly expressed in venom glands or putative venom genes in the Drosophila parasitoid wasps. CONCLUSIONS: Our study suggests that convergent evolution may not play a predominant force shaping gene expression levels in the venom gland of the Drosophila parasitoid wasps, offering novel insights into the co-evolution between venom and prey/host.

GluA1 Degradation by Autophagy Contributes to Circadian Rhythm Effects on Cerebral Ischemia Injury.

The mechanisms of many diseases, including central nervous system disorders, are regulated by circadian rhythms. The development of brain disorders such as depression, autism, and stroke is strongly associated with circadian cycles. Previous studies have shown that cerebral infarct volume is smaller at night (active phase) than during the day (inactive phase) in ischemic stroke rodent models. However, the underlying mechanisms remain unclear. Increasing evidence suggests that glutamate systems and autophagy play important roles in the pathogenesis of stroke. Here, we report that GluA1 expression was decreased and autophagic activity was increased in active-phase male mouse models of stroke compared with the inactive-phase models. In the active-phase model, induction of autophagy decreased the infarct volume, whereas inhibition of autophagy increased the infarct volume. Meanwhile, GluA1 expression was decreased following activation of autophagy and increased following inhibition of autophagy. We used Tat-GluA1 to uncouple p62, an autophagic adapter, from GluA1 and found that this blocked the degradation of GluA1, an effect similar to that of inhibition of autophagy in the active-phase model. We also demonstrated that knock-out of the circadian rhythm gene Per1 abolished the circadian rhythmicity of the volume of infarction and also abolished GluA1 expression and autophagic activity in wild-type (WT) mice. Our results suggest an underlying mechanism by which the circadian rhythm participates in the autophagy-dependent regulation of GluA1 expression, which influences the volume of infarction in stroke.SIGNIFICANCE STATEMENT Circadian rhythms affect the pathophysiological mechanisms of disease. Previous studies suggested that circadian rhythms affect the infarct volume in stroke, but the underlying mechanisms remain largely unknown. Here, we demonstrate that the smaller infarct volume after middle cerebral artery occlusion/reperfusion (MCAO/R) during the active phase is related to lower GluA1 expression and activation of autophagy. The decrease in GluA1 expression during the active phase is mediated by the p62-GluA1 interaction, followed by direct autophagic degradation. In short, GluA1 is the substrate of autophagic degradation, which mainly occurs after MCAO/R during the active phase but not the inactive phase.

Innovative Colorimetric NQO1 Detection Strategy via Substrate Competitive and Biomimetic Cascade Reactions with a Highly Active NADH Oxidase Mimic.

NAD(P)H: quinone oxidoreductase-1 (NQO1) plays critical roles in antioxidation and abnormally overexpresses in tumors. Developing a fast and sensitive method of monitoring NQO1 will greatly promote cancer diagnosis in clinical practice. This study introduces a transformative colorimetric detection strategy for NQO1, harnessing an innovative competitive substrate mechanism between NQO1 and a new NADH oxidase (NOX) mimic, cobalt-nitrogen-doped carbon nanozyme (CoNC). This method ingeniously exploits the differential consumption of NADH in the presence of NQO1 to modulate the generation of H2O2 from CoNC catalysis, which is then quantified through a secondary, peroxidase-mimetic cascade reaction involving Prussian blue (PB) nanoparticles. This dual-stage reaction framework not only enhances the sensitivity of NQO1 detection, achieving a limit of detection as low as 0.67 µg mL-1, but also enables the differentiation between cancerous and noncancerous cells by their enzymatic activity profiles. Moreover, CoNC exhibits exceptional catalytic efficiency, with a specific activity reaching 5.2 U mg-1, significantly outperforming existing NOX mimics. Beyond mere detection, CoNC serves a dual role, acting as both a robust mimic of cytochrome c reductase (Cyt c) and a cornerstone for enzymatic regeneration, thereby broadening the scope of its biological applications. This study not only marks a significant step forward in the bioanalytical application of nanozymes but also sets the stage for their expanded use in clinical diagnostics and therapeutic monitoring.

Semi-Ionic F Modified N-Doped Porous Carbon Implanted with Ruthenium Nanoclusters toward Highly Efficient pH-Universal Hydrogen Generation.

Developing high electroactivity ruthenium (Ru)-based electrocatalysts for pH-universal hydrogen evolution reaction (HER) is challenging due to the strong bonding strengths of key Ru─H/Ru─OH intermediates and sluggish water dissociation rates on active Ru sites. Herein, a semi-ionic F-modified N-doped porous carbon implanted with ruthenium nanoclusters (Ru/FNPC) is introduced by a hydrogel sealing-pyrolying-etching strategy toward highly efficient pH-universal hydrogen generation. Benefiting from the synergistic effects between Ru nanoclusters (Ru NCs) and hierarchically F, N-codoped porous carbon support, such synthesized catalyst displays exceptional HER reactivity and durability at all pH levels. The optimal 8Ru/FNPC affords ultralow overpotentials of 17.8, 71.2, and 53.8 mV at the current density of 10 mA cm-2 in alkaline, neutral, and acidic media, respectively. Density functional theory (DFT) calculations elucidate that the F-doped substrate to support Ru NCs weakens the adsorption energies of H and OH on Ru sites and reduces the energy barriers of elementary steps for HER, thus enhancing the intrinsic activity of Ru sites and accelerating the HER kinetics. This work provides new perspectives for the design of advanced electrocatalysts by porous carbon substrate implanted with ultrafine metal NCs for energy conversion applications.

Elucidating High Initial Coulombic Efficiency, Pseudocapacitive Kinetics and Charge Storage Mechanism of Antiperovskite Carbide Ni3ZnC0.7@rGO Anode for Fast Sodium Storage in Ether Electrolyte.

To explore novel electrode materials with in-depth elucidation of initial coulombic efficiency (ICE), kinetics, and charge storage mechanisms is of great challenge for Na-ion storage. Herein, a novel 3D antiperovskite carbide Ni3ZnC0.7@rGO anode coupled with ether-based electrolyte is reported for fast Na-ion storage, exhibiting superior performance than ester-based electrolyte. Electrochemical tests and density functional theory (DFT) calculations show that Ni3ZnC0.7@rGO anode with ether-based electrolyte can promote charge/ion transport and lower Na+ diffusion energy barrier, thereby improving ICE, reversible capacity, rate, and cycling performance. Cross-sectional-morphology and depth profiling surface chemistry demonstrate that not only a thinner and more homogeneous reaction interface layer with less side effects but also a superior solid electrolyte interface (SEI) film with a high proportion of inorganic components are formed in the ether-based electrolyte, which accelerates Na+ transport and is the significant reason for the improvement of ICE and other electrochemical properties. Meanwhile, electrochemical and ex situ measurements have revealed conversion, alloying, and co-intercalation hybrid mechanisms of the Ni3ZnC0.7@rGO anode based on ether electrolyte. Interestingly, the Na-ion capacitors (SICs) designed by pairing with activated carbon (AC) cathode exhibit favorable electrochemical performance. Overall, this work provides deep insights on developing advanced materials for fast Na-ion storage.

Gold Nanoparticle Delivery of Glut1 SiRNA Facilitates Glucose Starvation Therapy in Lung Cancer.

Glucose transporter protein-1 (Glut1), is highly expressed in many cancer types and plays a crucial role in cancer progression through enhanced glucose transport. Its overexpression is associated with aggressive tumor behavior and poor prognosis. Herein, the nucleic acids modified gold nanoparticles (AuNPs) was synthesized to deliver small interfering RNA (siRNA) against Glut1 by microRNA 21 (miR-21) triggers toehold-mediated strand displacement reaction for lung cancer starvation therapy. Overexpression of miR-21 triggers toehold-mediated strand displacement, releasing the siRNA to knockdown of Glut1 in cancer cell instead of normal cell. Furthermore, the glucose oxidase-like activity of the AuNPs accelerates intracellular glucose consumption, promoting cancer cell starvation. The engineered AuNPs@anti-miR-21/siGlut1 complex inhibits cancer cell proliferation, xenograft tumor growth and promotes apoptosis through glucose starvation and ROS cascade signaling, underscoring its potential as an effective therapeutic strategy for lung cancer.

The evolution history of an allotetraploid mangrove tree analysed with a new tool Allo4D.

Mangrove species are broadly classified as true mangroves and mangrove associates. The latter are amphibious plants that can survive in the intertidal zone and reproduce naturally in terrestrial environments. Their widespread distribution and extensive adaptability make them ideal research materials for exploring adaptive evolution. In this study, we de novo assembled two genomes of mangrove associates (the allotetraploid Barringtonia racemosa (2n = 4x = 52) and diploid Barringtonia asiatica (2n = 2x = 26)) to investigate the role of allopolyploidy in the evolutionary history of mangrove species. We developed a new allotetraploid-dividing tool Allo4D to distinguish between allotetraploid scaffold-scale subgenomes and verified its accuracy and reliability using real and simulated data. According to the two subgenomes of allotetraploid B. racemosa divided using Allo4D, the allopolyploidization event was estimated to have occurred approximately one million years ago (Mya). We found that B. racemosa, B. asiatica, and Diospyros lotus shared a whole genome duplication (WGD) event during the K-Pg (Cretaceous-Paleozoic) period. K-Pg WGD and recent allopolyploidization events contributed to the speciation of B. racemosa and its adaptation to coastal habitats. We found that genes in the glucosinolates (GSLs) pathway, an essential pathway in response to various biotic and abiotic stresses, expanded rapidly in B. racemosa during polyploidization. In summary, this study provides a typical example of the adaptation of allopolyploid plants to extreme environmental conditions. The newly developed tool, Allo4D, can effectively divide allotetraploid subgenomes and explore the evolutionary history of polyploid plants, especially for species whose ancestors are unknown or extinct.

A novel homozygous nonsense variant of STX2 underlies non-obstructive azoospermia in a consanguineous Chinese family.

Male infertility is a widespread population health concern, causing various degrees of adverse fertility outcomes. We determined the genetic cause of an infertile male from a consanguineous family, expanding the mutant spectrum of male infertility. A non-obstructive azoospermia (NOA) patient was recruited, and histological type of human testicular tissue of the patient categorized as maturation arrest. We identified a novel loss-of-function variant of syntaxin 2 (STX2) (c.142C>T:p.Gln48*) by performing Whole-exome sequencing (WES) on the NOA patient from a consanguineous Chinese family. Sanger sequencing confirmed the p.Gln48* variant was maternally and paternally inherited. The variant was predicted to be deleterious and resulted in aberrant changes to structure and function of STX2 by In silico analysis. In summary, we reported for the first time that a nonsense variant occurred in the exon region of STX2 in an infertile male presenting with NOA, which was beneficial for diagnosis and therapies of NOA.

Elevated Serum IL-17A in Kawasaki Disease Patients Predicts Responsiveness to Intravenous Immunoglobulin Therapy.

INTRODUCTION: This study aimed to investigate the correlation between serum interleukin (IL)-17A levels and responsiveness to intravenous immunoglobulin (IVIG) therapy in Kawasaki disease (KD) patients. METHODS: A retrospective analysis on data from 192 KD patients admitted to the Anqing Municipal Hospital between January 2021 and January 2024 was conducted. Patients were categorized into IVIG-nonresponsive and IVIG-sensitive groups as per the treatment outcomes. Outcome measures included serum IL-17A levels, left coronary artery (LCA) Z scores, and relevant laboratory parameters. Logistic regression analysis was performed to identify predictive factors for IVIG responsiveness, and diagnostic performance was assessed using receiver operating characteristic (ROC) curves and calculation of the area under the curve (AUC). RESULTS: A total of 40 IVIG-nonresponsive cases and 152 IVIG-sensitive cases were included. Prior to intervention, IVIG-nonresponsive patients had significantly higher serum IL-17A levels compared to IVIG-sensitive patients, with a statistically significant difference. After intervention, serum IL-17A levels significantly decreased in IVIG-sensitive patients while remaining elevated in IVIG-nonresponsive patients. IVIG-nonresponsive patients exhibited significantly higher levels of C-reactive protein (CRP), white blood cell count (WBC), NE, and ALT compared to IVIG-sensitive patients, whereas no significant differences in LCA Z scores between the two groups existed. Multivariable logistic regression analysis identified pre-IL-17A, CRP, WBC, and ALT as independent predictors of IVIG-nonresponsiveness in KD. When pre-IL-17A was ≥39.96 pg/mL, the specificity and sensitivity for predicting IVIG-nonresponsive KD were 63.9% and 71.9%, respectively, with an AUC of 0.637. The combined diagnosis of IL-17A, CRP, WBC, and ALT yielded an AUC of 0.780. CONCLUSION: Serum IL-17A levels were remarkably elevated in IVIG-nonresponsive KD patients both before and after intervention. A serum IL-17A level (≥39.96 pg/mL) demonstrated good predictive profile for IVIG-nonresponsive KD, and combining IL-17A with CRP, WBC, and ALT improved diagnostic performance.