Environmental Biology of Fishes最新文献

{"title":"Effects of Astragalus Polysaccharide and Isatis indigotica Extract Synergy on the Antioxidant Status, Inflammation, Autophagy, Apoptosis, and Intestinal Health of Larimichthys crocea Juveniles","authors":"Zhichu Chen, Chao Zeng, Ai Wang, Huiyu Wang, Xin Zhi, Zhengbang Chen, Huiyuan Lv, Qiong Qi, Pan Wang, Jianchun Shao, Xinhua Chen","doi":"10.3390/fishes10110593","DOIUrl":"https://doi.org/10.3390/fishes10110593","url":null,"abstract":"This research aimed to examine the combined influence of Astragalus polysaccharide (APS) and Isatis indigotica extract (IIE) dietary supplements on oxidative-inflammatory status, cellular homeostasis, and intestinal integrity in large yellow croaker (Larimichthys crocea). Three replicates of experimental fish (n = 160) received one of five dietary regimens: a basal control (CON) diet, the CON diet containing 0.1% APS (AP), and the AP diet supplemented with 0.05%, 0.1%, and 0.15% IIE (AI1, AI2, and AI3) for 8 weeks. The combined supplements, particularly in the AI2 group, significantly improved intestinal morphology and enhanced the activities of key digestive enzymes. Gene expression analysis revealed that the APS-IIE combination consistently upregulated the intestinal mRNA abundance of major tight junction proteins (CLDN4, OCLN, ZO1, ZO2) compared to the CON or AP groups. Liver antioxidant capacity was strengthened (enhanced CAT capacity), as evidenced by a significant reduction in lipid peroxidation (MDA) levels. In the head kidney, the combination downregulated the expression of pro-inflammatory cytokines (IL8, TNF) and toll-like receptors (TLR1, TLR2, TLR5), and promoted the expression of anti-inflammatory cytokines (IL10, TGFB1). Furthermore, dietary supplementation modulated the crosstalk between autophagy and apoptosis, indicated by altered expression of key marker genes (e.g., increased MAP1LC3B and decreased CASP3/8/9). In conclusion, the simultaneous inclusion of APS and IIE in diets promotes intestinal health, strengthens antioxidant status, and alleviates inflammatory responses, with the 0.1% APS + 0.1% IIE (AI2) formulation demonstrating the most pronounced benefits.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 11","pages":"593-593"},"PeriodicalIF":0.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/11/593/pdf?version=1763525170","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Tissue Stable Isotope Analysis Reveals the Feeding Ecology of Dominant Shark Bycatch Species in the Northern South China Sea","authors":"Kui Zhang, Pengli Xiong, Zuozhi Chen, Youwei Xu","doi":"10.3390/fishes10110583","DOIUrl":"https://doi.org/10.3390/fishes10110583","url":null,"abstract":"Understanding the feeding mechanisms and interspecific coexistence of sharks is crucial for effective conservation. This study conducted stable isotope analysis on muscle and liver samples from 449 individuals of eight common bycatch shark species collected via bottom trawling in the northern South China Sea (NSCS). Results revealed significant differences in δ13C and δ15N values among species and tissue types. Scoliodon laticaudus exhibited the highest trophic position (TPmuscle = 4.60 ± 0.33; TPliver = 4.53 ± 0.29), while Apristurus platyrhynchus had the lowest (TPmuscle = 2.97 ± 0.44; TPliver = 2.75 ± 0.53). Muscle and liver isotopic signals were consistent, but δ13C differences indicated distinct carbon sources, with Carcharhinus sorrah linked to deep-sea organic matter and S. laticaudus to coastal inputs. Significant correlations between δ13C/δ15N and body length in A. platyrhynchus and Cephaloscyllium fasciatum suggest ontogenetic shifts in diet and habitat toward deeper waters. Trophic niche analysis using corrected standard ellipse area (SEAc) showed Halaelurus burgeri with the widest trophic niche (SEAc > 1.7‰2), reflecting a broad diet, while C. fasciatum had the narrowest (SEAc < 0.3‰2), indicating specialized feeding. Additionally, H. burgeri and C. sarawakensis exhibited significant niche differentiation, reducing interspecific competition, whereas C. fasciatum and Squalus megalops showed high niche overlap, suggesting intense resource competition. The narrower liver niche of C. sarawakensis may reflect recent habitat constriction due to bottom trawling. This study elucidates the feeding ecology and habitat resource utilization of NSCS sharks, providing a scientific basis for effective conservation strategies for shark populations in the region.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 11","pages":"583-583"},"PeriodicalIF":0.0,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/11/583/pdf?version=1763029999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"β,β-Dimethylacrylshikonin Alleviates Zebrafish (Danio rerio) Soyasaponin-Induced Enteritis by Maintaining Intestinal Homeostasis and Improving Intestinal Immunity and Metabolism","authors":"Ming Liu, Xin Lü, Leong‐Seng Lim, Yinhui Peng, Lulu Liu, Kianann Tan, Peng Xu, Mingzhong Liang, Yingrui Wu, Qingfang Gong, Xiaohui Cai","doi":"10.3390/fishes10110567","DOIUrl":"https://doi.org/10.3390/fishes10110567","url":null,"abstract":"Soyasaponin intolerance is common in ancient fish species, making them susceptible to enteritis caused by dietary soybean meal. β,β-Dimethylacrylshikonin is the key active monomer found in Lithospermum erythrorhizon and is known for its multiple pharmacological activities. However, its effect on soybean meal-induced enteritis remains unknown. The administration of 2 g/kg of β,β-Dimethylacrylshikonin (LE) effectively alleviated 5 g/kg of soyasaponin-induced histopathological changes and dysfunction, as evidenced by the expression of inflammation-related genes (il-1β, il-8, and il10). Regarding the gut microbiota composition, LE therapy decreased the population of inflammation-linked Proteobacteria and concurrently elevated the proportion of Fusobacteriota, effectively sustaining the balance of the zebrafish gut microbiota. Moreover, at the genus level, LE treatment also increased the abundance of Cetobacterium. Transcriptional results suggested that LE intervention mainly regulated immune-related pathways, including cytokine–cytokine receptor interaction, the TGF-beta signaling pathway, taurine and hypotaurine metabolism, and arachidonic acid metabolism. In conclusion, 5 g/kg of soyasaponins caused intestinal injury in zebrafish, and β,β-Dimethylacrylshikonin can reduce intestinal inflammation by regulating the intestinal microbial balance and metabolic disorder, with the best effect at 2 g/kg.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 11","pages":"567-567"},"PeriodicalIF":0.0,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/11/567/pdf?version=1762392618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147877255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Application of Infectious Hematopoietic Necrosis Virus Antigen-Specific DAS-ELISA Detection Method","authors":"Jing-Zhuang Zhao, Min Wu, Liming Xu, Yizhi Shao, Weitong Liu, Tongyan Lu","doi":"10.3390/fishes10100533","DOIUrl":"https://doi.org/10.3390/fishes10100533","url":null,"abstract":"Infectious hematopoietic necrosis virus (IHNV), a salmonid rhabdovirus, causes severe mortality exceeding 90% in both wild and farmed salmon and trout. Frequent outbreaks of IHNV highlight the urgent need for rapid detection methods to support effective prevention and control. This study developed a double-antibody sandwich ELISA (DAS-ELISA) targeting the nucleocapsid (N) protein of IHNV. Two peptides derived from the N protein—selected for their strong antigenicity, high level of conservation, and surface accessibility—were used as immunogens to generate two specific monoclonal antibodies. Following optimization, the DAS-ELISA was established using monoclonal antibody N-15 as the capture antibody and horseradish peroxidase (HRP)-conjugated antibody N-106 as the detection antibody. The results of this study demonstrated that DAS-ELISA exhibited high specificity for multiple IHNV strains and showed no cross-reactivity with IPNV, SVCV, or VHSV. The detection sensitivity of DAS-ELISA for IHNV was determined to be 103 TCID50/mL. Parallel analysis of 293 clinical samples using DAS-ELISA and WOAH reference method demonstrated a concordance rate of 92.83% (κ = 0.856). These results confirm that the established DAS-ELISA exhibits high sensitivity, specificity, broad-spectrum applicability, and repeatability. In conclusion, this DAS-ELISA provides a reliable and efficient tool for high-throughput early detection of IHNV infection in clinical settings.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 10","pages":"533-533"},"PeriodicalIF":0.0,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/10/533/pdf?version=1760946321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147897990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryonic and Larval Development of an Interspecific Grouper Backcross Between the Kelp Grouper (Epinephelus moara) ♀ and KGGG (E. moara ♀ × E. lanceolatus ♂) ♂","authors":"Yidan Xu, Yongsheng Tian, Shihao Wang, Tangtang Ding, Linna Wang, Zhentong Li, Linlin Li, Yang Liu","doi":"10.3390/fishes10100488","DOIUrl":"https://doi.org/10.3390/fishes10100488","url":null,"abstract":"Backcrossing serves as an effective tool for interspecific gene introgression, facilitating germplasm improvement. To develop superior grouper aquaculture varieties, in this study, a backcrossed breed was constructed by crossing a male hybrid grouper, KGGG (Epinephelus moara ♀ × E. lanceolatus ♂), with a female parent kelp grouper (KG; E. moara). Here, we observed embryonic, larval development, and morphological changes in KG × KGGG. Additionally, the total length and body weight of the backcrossed breed and maternal parent were compared at 160 d post hatching (dph). The results showed that fertilization and the hatching rate were 73.23 ± 4.23% and 51.74 ± 3.67%, respectively, and the egg size was 0.89 ± 0.03 mm. Hatching occurred 23:19 h after fertilization at 25 ± 1 °C, and the newly hatched larvae were 1.94 ± 0.13 mm in length. Furthermore, at 160 dph, the total length and body weight of the backcrossed breed were 1.2-fold and 1.9-fold greater, respectively, when compared with those of the maternal parent. Importantly, it is possible that backcrossed KG × KGGG could become a dominant strain in grouper aquaculture practices.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 10","pages":"488-488"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/10/488/pdf?version=1759321093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147879210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the NFAT Gene Family in Grass Carp (Ctenopharyngodon idellus) and Functional Analysis of NFAT1 During GCRV Infection","authors":"Yao Shen, Yitong Zhang, Chen Chen, Shitao Hu, Jia Liu, Yiling Zhang, Tiaoyi Xiao, Baohong Xu, Qiaolin Liu","doi":"10.3390/fishes10090422","DOIUrl":"https://doi.org/10.3390/fishes10090422","url":null,"abstract":"Nuclear factors of activated T cells (NFATs) are pivotal regulatory factors of immune responses, primarily by modulating T cell activity and regulating inflammatory cytokine gene transcription. The grass carp reovirus (GCRV) triggers a serious hemorrhagic condition, posing a significant threat to sustainable grass carp (Ctenopharyngodon idella) aquaculture. However, the precise function of NFAT in the host’s defense against GCRV infection is mostly undefined. This study comprehensively identified and characterized the NFAT genetic family in grass carp, cloned grass carp NFAT1 (CiNFAT1), and investigated its expression and function during GCRV infection. Eight NFAT genes encoding seventeen isoforms have been detected within the grass carp’s genomic sequence, distributed across six different chromosomes. Comparative analysis revealed homology with zebrafish NFATs. CiNFAT1 possesses a 2697 bp open reading frame, encoding 898 amino acids, and contains conserved Rel homology domain (RHD) and NFAT-homology (IPT) domains. Quantitative PCR (qPCR) revealed ubiquitous CiNFAT1 expression in healthy grass carp tissues, with the highest expression in gills and skin and the lowest in liver. Following GCRV challenge in vivo, CiNFAT1 expression in immune tissues (liver, spleen, kidney, gill, intestine) showed dynamic changes over time. In vitro experiments in CIK cells demonstrated that CiNFAT1 expression peaked at 12 h post-GCRV infection. Further functional studies revealed that overexpression of CiNFAT1 significantly reduced GCRV replication at 36 h post-infection. This reduction was accompanied by elevated expression of type I interferon (IFN-I) and interferon regulatory factor 7 (IRF7) at 24 and 36 h, respectively, as well as modulated IL-2, IL-8, and IL-10. Conversely, RNA interference-mediated knockdown of CiNFAT1 enhanced GCRV VP5 and VP7 mRNA levels and suppressed IL-2 and IL-8 expression. These results suggest that CiNFAT1 contributes to anti-GCRV immunity by promoting antiviral and inflammatory cytokine responses, thereby inhibiting viral replication. This study provides a foundational understanding of the NFAT genetic family in grass carp and highlights an important role of CiNFAT1 in mediating the body’s inherent defense mechanism against GCRV infection, offering insights for disease control strategies in aquaculture.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 9","pages":"422-422"},"PeriodicalIF":0.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/9/422/pdf?version=1755868650","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147889701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rutin Inhibits Histamine-Induced Cytotoxicity of Zebrafish Liver Cells via Enhancing Antioxidant and Anti-Inflammatory Properties","authors":"Ke Cheng, Apeng Liu, Di Peng, Lixue Dong, Yangyang Liu, Juan Tian, Hua Wen, Yongju Luo, Zhongbao Guo, Ming Jiang","doi":"10.3390/fishes10080408","DOIUrl":"https://doi.org/10.3390/fishes10080408","url":null,"abstract":"Histamine can damage the antioxidant and immune systems in fish and crustaceans. Rutin, a natural substance with a diverse phenolic structure, has demonstrated antioxidant and anti-inflammatory properties. However, whether rutin can mitigate histamine-induced negative effects remains uninvestigated in fish models. This study investigated the effect of 0.1–100 μM rutin preincubation on histamine (29.5 mM)-induced cytotoxicity in zebrafish liver cells (ZFL) and its potential mechanisms. Results showed that 0.1–100 μM rutin significantly improved ZFL cell survival following histamine stimulation and protected cellular morphology. Rutin inhibited the adverse effects of histamine on ZFL by scavenging or suppressing the accumulation of reactive oxygen species (ROS), H2O2, and malondialdehyde (MDA), while increasing the activities of superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC). At the protein level, 10 μM rutin significantly promoted Nrf2 protein expression. HO-1 protein was significantly up-regulated after preincubation with 0.1–10 μM rutin, whereas IL-1β protein levels were significantly down-regulated. The mechanism may involve activation of the Nrf2 antioxidant signaling pathway and inhibition of the NF-κB inflammatory signaling pathway. In summary, within the experimental concentration range, 10 μM rutin showed the strongest inhibitory effects on histamine-induced ZFL cell death and oxidative stress. This study provides a theoretical basis and data support for evaluating rutin’s feasibility as a green aquatic feed additive.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 8","pages":"408-408"},"PeriodicalIF":0.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/8/408/pdf?version=1755599295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147897975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toxic Effects of Tetramethyl Bisphenol A on Embryonic–Larval Development of Zebrafish (Danio rerio)","authors":"Eric Yin, Manwen Zeng, Haipeng Yan, Jiahao Gao, Zuchun Chen, Ning Zhang, Yusong Guo, Zhongduo Wang, Zhongdian Dong","doi":"10.3390/fishes10080407","DOIUrl":"https://doi.org/10.3390/fishes10080407","url":null,"abstract":"Tetramethyl bisphenol A (TMBPA), a novel alternative to Bisphenol A, is widely used as an industrial flame retardant and a raw material for tetramethyl polycarbonate plastics. With the increasing use of TMBPA, its aquatic ecological risks remain unclear. Therefore, this study investigated the developmental toxicity of TMBPA using zebrafish (Danio rerio) as a model, exposing embryos to 0.5, 5, 50, and 200 μg/L TMBPA for 120 h. The results showed that treatment with 5, 50, and 200 μg/L TMBPA decreased the hatching rate of zebrafish embryos at 48 h post-fertilization (hpf), while no significant difference was observed at 72 hpf. Meanwhile, TMBPA exposure at all concentrations showed no significant effect on the survival rate. Furthermore, a high concentration of TMBPA (200 μg/L) significantly reduced the total length and suppressed swimming ability in zebrafish larvae. In addition, gene expression analysis revealed impacts on antioxidant system (cat, gpx, mn-sod, keap1, ucp2, nrf2), hypothalamic–pituitary–thyroid (HPT) axis (ttr, ugt1ab, trβ), cardiac developmental (tbx2b, myl7, bmp4, notch1b, amhc), and the hypothalamic–pituitary–adrenal (HPA) axis (pomca and nr3c1). The results indicated that TMBPA exposure adversely disrupted embryo hatching and larval development of zebrafish, accompanied by altering the expression of functional genes in larvae. These results provide further evidence for the potential environmental hazard posed by TMBPA.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 8","pages":"407-407"},"PeriodicalIF":0.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/8/407/pdf?version=1755159502","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depletion of Albendazole and Its Metabolites and Their Impact on the Gut Microbial Community Following Multiple Oral Dosing in Yellow River Carp (Cyprinus carpio haematopterus)","authors":"Yue Liu, Yan Dai, Yanni Zhang, Wenrui Wang, Yuxin Chen, Yang‐Guang Jin, Long-Ji Sun, Shihao Li, Fang Yang, Fang Yang, Xing‐Ping Li, Fan Yang, Fan Yang","doi":"10.3390/fishes10080410","DOIUrl":"https://doi.org/10.3390/fishes10080410","url":null,"abstract":"Healthy Yellow River carp (Cyprinus carpio haematopterus) reared at a water temperature of 23 ± 0.6 °C were orally administered albendazole (ABZ) at a dose of 12 mg/kg body weight (BW) once daily for seven consecutive days. At predetermined time points after the final administration, five fish were randomly selected for sampling. Plasma, skin-on-muscle, liver, and kidney tissues were collected, and the concentrations of ABZ and its three metabolites—albendazole sulfoxide (ABZSO), albendazole sulfone (ABZSO2), and albendazole-2-aminosulfone (ABZ-2-NH2−SO2)—were determined using high-performance liquid chromatography (HPLC). The results indicated that ABZ and ABZSO were widely distributed across tissues, while ABZSO2 and ABZ-2-NH2-SO2 were only present at trace levels. Pharmacokinetic analysis of ABZ and ABZSO in plasma and tissues was performed using noncompartmental analysis (NCA). ABZ peaked in plasma at 0.73 μg/mL at 24 h after the last administration, with an elimination half-life (t1/2λZ) of 38.56 h. ABZSO reached a peak plasma concentration of 1.54 μg/mL at 24 h, with a t1/2λZ of 53.73 h. According to China’s national standard, where ABZ-2-NH2−SO2 is the marker residue with a maximum residue limit (MRL) of 100 μg/kg in fish skin-on muscle, no withdrawal period was necessary. However, based on the European Union standard—which uses the sum of ABZ and its three metabolites as the marker residue and an MRL of 100 μg/kg in ruminants—a withdrawal period of 16 days (or 351 °C-days) was required. Additionally, the study assessed changes in the intestinal microbiota following multiple oral doses of ABZ. The results indicated that ABZ administration significantly altered microbial diversity and composition in a dose- and time-dependent manner. After drug withdrawal, the intestinal microbiota gradually returned to baseline levels, similar to the untreated control group.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 8","pages":"410-410"},"PeriodicalIF":0.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/8/410/pdf?version=1755253212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147878228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Characterization and Antiviral Function Against GCRV of Complement Factor D in Barbel Chub (Squaliobarbus curriculus)","authors":"Yu Xiao, Zhao Lv, Yuling Wei, Mengyuan Zhang, Hong Yang, Chao Huang, Tiaoyi Xiao, Yilin Li","doi":"10.3390/fishes10080370","DOIUrl":"https://doi.org/10.3390/fishes10080370","url":null,"abstract":"The barbel chub (Squaliobarbus curriculus) exhibits remarkable resistance to grass carp reovirus (GCRV), a devastating pathogen in aquaculture. To reveal the molecular basis of this resistance, we investigated complement factor D (DF)—a rate-limiting serine protease governing alternative complement pathway activation. Molecular cloning revealed that the barbel chub DF (ScDF) gene encodes a 1251-bp cDNA sequence translating into a 250-amino acid protein. Crucially, bioinformatic characterization identified a unique N-glycosylation site at Asn139 in ScDF, representing a structural divergence absent in grass carp (Ctenopharyngodon idella) DF (CiDF). While retaining a conserved Tryp_SPc domain harboring the catalytic triad (His61, Asp109, and Ser204) and substrate-binding residues (Asp198, Ser219, and Gly221), sequence and phylogenetic analyses confirmed ScDF’s evolutionary conservation, displaying 94.4% amino acid identity with CiDF and clustering within the Cyprinidae. Expression profiling revealed constitutive ScDF dominance in the liver, and secondary prominence was observed in the heart. Upon GCRV challenge in S. curriculus kidney (SCK) cells, ScDF transcription surged to a 438-fold increase versus uninfected controls at 6 h post-infection (hpi; p < 0.001)—significantly preceding the 168-hpi response peak documented for CiDF in grass carp. Functional validation showed that ScDF overexpression suppressed key viral capsid genes (VP2, VP5, and VP7) and upregulated the interferon regulator IRF9. Moreover, recombinant ScDF protein incubation induced interferon pathway genes and complement C3 expression. Collectively, ScDF’s rapid early induction (peaking at 6 hpi) and multi-pathway coordination may contribute to barbel chub’s GCRV resistance. These findings may provide molecular insights into the barbel chub’s high GCRV resistance compared to grass carp and novel perspectives for anti-GCRV breeding strategies in fish.","PeriodicalId":11799,"journal":{"name":"Environmental Biology of Fishes","volume":"10 8","pages":"370-370"},"PeriodicalIF":0.0,"publicationDate":"2025-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2410-3888/10/8/370/pdf?version=1754104524","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147880775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}