Fish & shellfish immunology最新文献

{"title":"Integrated mortality rates and transcriptome comparative analysis between wild and artificially selected ark shell (Scapharca subcrenata) populations in response to Vibrio anguillarum infection","authors":"Peizhen Tian ,&nbsp;Yanming Su ,&nbsp;XingLei Wang ,&nbsp;Feng Wang ,&nbsp;Bo Liu ,&nbsp;Yuming Zhao","doi":"10.1016/j.fsi.2026.111182","DOIUrl":"10.1016/j.fsi.2026.111182","url":null,"abstract":"<div><div>The survival ability of artificially selected ark shells (<em>Scapharca subcrenata</em>) and wild populations was assessed under different combinations of temperatures (25, 27, 29, and 31 °C) and <em>Vibrio anguillarum</em> immersion concentrations (0, 3 × 10⁸, 6 × 10⁸, 9 × 10⁸, 12 × 10⁸, 15 × 10⁸, and 18 × 10⁸ CFU/mL). Significant differences in mortality rates between the two ark shell populations were observed across most temperature and immersion concentration combinations, with only a few exceptions. The gene expression profiles of selected and wild ark shells were analyzed through transcriptome sequencing following exposed to 1 × 10⁸ CFU/mL of <em>V. anguillarum</em> strain PL2. Gene Ontology (GO) functional classification of the 1558 differentially expressed genes (DEGs) common to the three comparisons revealed that <u>‘</u>cellular process<u>’</u>, <u>‘</u>membrane<u>’</u> and <u>‘</u>binding<u>’</u> were the most enriched terms across the biological process, cellular component, and molecular function categories in the D (treated wild ark shells) _vs_C (Untreated wild ark shells were used as the control group) and KD (treated selectively bred ark shells) _vs_D groups. COG analysis reveals that the <u>‘</u>Energy Production and Conversion<u>’</u> category is significantly downregulated in the KD_vs_D comparison compared to the D_vs_C and C_vs_KD comparisons. Heatmap visualization of DEGs across C, D, and KD groups showed numerous genes exhibiting inverse expression trends among the groups. Among the top 10 KEGG pathways identified across the three comparison groups, no pathways were shared between the KD_vs_D group and the other two comparisons, suggesting that these pathways may be related to the resistance of ark shells to <em>V. anguillarum</em>. Our study indicates that ark shell populations selected under high-intensity environmental stress exhibit greater tolerance to elevated temperatures and <em>V</em>. <em>anguillarum</em>. This further demonstrates that selecting ark shells under stress conditions may enhance their survival rates in aquaculture. These findings will deepen the understanding of bivalve adaptability to environmental changes and aid in the advancement of shellfish aquaculture practices.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111182"},"PeriodicalIF":3.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the immunoprotective effects of two Infectious Spleen and Kidney Necrosis Virus (ISKNV) oral vaccines on largemouth bass","authors":"Xuan Zhang ,&nbsp;Yunshang Ning ,&nbsp;Zengjian Liang ,&nbsp;Jinqiao Cao ,&nbsp;Tao Xu ,&nbsp;Jiayi Luo ,&nbsp;Zemiao Zhang ,&nbsp;Yingjing Chen ,&nbsp;Jingguang Wei ,&nbsp;Qiwei Qin ,&nbsp;Sumei Xiao ,&nbsp;Sheng Zhou","doi":"10.1016/j.fsi.2026.111189","DOIUrl":"10.1016/j.fsi.2026.111189","url":null,"abstract":"<div><div>The high pathogenicity and mortality rate of infectious spleen and kidney necrosis virus (ISKNV) have significantly threatened the development of largemouth bass aquaculture in China. Oral vaccines are urgently needed in the aquaculture industry. This study successfully constructed recombinant strains EBY100/pYD1-ISKNV and WB600/pEB03-CotC-ISKNV that can express ISKNV MCP using surface display platforms of <em>Saccharomyces cerevisiae</em> and <em>Bacillus subtilis</em>. Oral immunization of largemouth bass was conducted to evaluate the protective efficacy of both oral vaccines. Following oral immunization, the relative expression levels of <em>IFN-γ</em>, <em>TNF-α</em>, <em>IL-1</em>, <em>CD8α</em>, <em>MHC-Ⅰ</em>, <em>IgM</em>, and <em>IgT</em> in the spleen and head kidney tissues of largemouth bass and serum-specific antibody levels in the E-I and W-I groups were significantly higher compared to the PBS group. Following ISKNV challenge, the survival rate of the E-I group and W-I group were 53.3 % and 50.0 %, respectively, with the relative percent survival (RPS) of 30.0 % and 25.0 %. Viral load detection revealed significantly lower viral loads in the E-I and W-I groups compared to the PBS group. Histopathological examination of tissue sections revealed that no obvious lesions were observed in the liver, spleen, and head kidney of largemouth bass immunized with either oral vaccine compared to the PBS group that exhibited severe lesions in the liver, spleen, and head kidney. In summary, oral administration of EBY100/pYD1-ISKNV and WB600/pEB03-CotC-ISKNV activated both innate and adaptive immune responses in largemouth bass, demonstrating efficacy in preventing ISKNV infection. The two oral vaccines developed in this study provide novel strategies for controlling ISKNV.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111189"},"PeriodicalIF":3.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fish Meteorin-like factor promotes migration, proliferation and phagocytic activity of monocytes/macrophages","authors":"Yueshuang Ji ,&nbsp;Yinghao Huang ,&nbsp;Shengbin Lu ,&nbsp;Weihua Zhao ,&nbsp;Liwen Zhu ,&nbsp;Wa Gao ,&nbsp;Jianhua Feng ,&nbsp;Gaoliang Yuan ,&nbsp;Jun Zou ,&nbsp;Junya Wang","doi":"10.1016/j.fsi.2026.111193","DOIUrl":"10.1016/j.fsi.2026.111193","url":null,"abstract":"<div><div>Meteorin-like (Metrnl) is a cytokine known to play multifunctional roles in mammalian immunity, yet its immunoregulatory role in teleost remains largely unexplored. In the present study, we systematically investigate the effects of Metrnl on primary monocytes/macrophages (Mo/Mφ) in grass carp (<em>Ctenopharyngodon idella</em>). <em>In vitro</em>, Metrnl significantly increased the viability of primary Mo/Mφ, with increases of 12.7% on day 3 and 7.9% on day 6, as determined by flow cytometric quantification of MCSFR⁺ cells across multiple biological replicates. Furthermore, Metrnl stimulation promoted Mo/Mφ proliferation and phagocytic activity, resulting in absolute increases of 12.43% and 16.86%, respectively, calculated as the proportion of EdU⁺MCSFR⁺ or Beads⁺MCSFR⁺ cells within the total MCSFR⁺ population. Consistent with these findings, <em>in vivo</em> experiments using a Metrnl-expressing plasmid demonstrated enhanced Mo/Mφ proliferation and phagocytosis. Moreover, Metrnl also significantly upregulated the mRNA levels of the chemokines <em>Cxcl8</em> and <em>Cxcl11.1b</em>, indicating its ability to recruit Mo/Mφ to target sites by activating chemokine-mediated chemotactic signaling. Importantly, neutralization of Metrnl with a specific antibody markedly impaired the enhanced Mo/Mφ recruitment, proliferation and phagocytosis, confirming that the effect is specifically mediated by Metrnl. Our results demonstrate that Metrnl acts as an important regulatory factor that activates and enhances Mo/Mφ-mediated innate immune response.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111193"},"PeriodicalIF":3.9,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IL-7 enhances the protective efficacy of inactivated grass carp reovirus vaccine as adjuvant in grass carp (Ctenopharyngodon idella)","authors":"Shijie Wang ,&nbsp;Yizhong Lu ,&nbsp;Yuezong Xu ,&nbsp;Guanyu Chen ,&nbsp;Jingjing Zhang ,&nbsp;Jianguo Su ,&nbsp;Chunrong Yang","doi":"10.1016/j.fsi.2026.111183","DOIUrl":"10.1016/j.fsi.2026.111183","url":null,"abstract":"<div><div>Grass carp reovirus (GCRV) causes severe hemorrhagic disease and significant threat to grass carp (<em>Ctenopharyngodon idella</em>) aquaculture. Although inactivated vaccines are commonly used, their limited protective efficacy necessitates effective adjuvants. In this study, recombinant grass carp interleukin-7 (rIL-7) and its enterokinase-cleaved form (EK rIL-7), obtained by removing the fusion tag using enterokinase, were successfully expressed, purified, and evaluated as adjuvants for an inactivated GCRV vaccine. Following GCRV challenge, both rIL-7 adjuvanted and EK rIL-7 adjuvanted vaccines significantly increased the survival of grass carp and effectively suppressed viral replication in the head kidney and spleen. Histopathological examination further confirmed that fish in the IL-7 adjuvant exhibited significantly reduced tissue damage compared to other treatments. Additionally, IL-7 enhanced both innate and adaptive immune responses in grass carp. The activities of serum enzymes (SOD, LDH and LZM) in the groups receiving IL-7 in combination with the vaccine increased significantly, reflecting the enhancement of antioxidant capacity and non-specific immune defense ability. In parallel, IL-7 treatment promoted IgM synthesis at both the transcriptional and serum antibody levels and increased the expression of immune-related genes such as CD4(-1, −2), MHCII (α, β), IFN-γ2, and IL-1β, indicating the activation of both humoral and cellular immune pathways. However, the difference between EK rIl-7 and rIl-7 is not significant. Collectively, these findings demonstrate that IL-7 acts as a potent adjuvant to enhance the protective efficacy of inactivated GCRV vaccines, and provide valuable insights for exploring other cytokines as immune adjuvants in the prevention of viral diseases in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111183"},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of VxrB in Vibrio harveyi and evaluation of a VxrB knock-out as a vaccine candidate","authors":"Yinhui Peng ,&nbsp;Xin Lu ,&nbsp;Ming Liu ,&nbsp;Shuo Hu ,&nbsp;Lulu Liu ,&nbsp;Renjie Li ,&nbsp;LuJia Yang ,&nbsp;Xiaohui Cai ,&nbsp;Shuanghu Cai","doi":"10.1016/j.fsi.2026.111186","DOIUrl":"10.1016/j.fsi.2026.111186","url":null,"abstract":"<div><div><em>Vibrio harveyi</em> is a major bacterial pathogen in marine aquaculture and can cause serious disease outbreaks in fish and invertebrates. Two-component systems help bacteria sense environmental change and adjust gene expression, including genes linked to virulence. <em>VxrB</em> is a response regulator that has been connected to virulence control in other <em>Vibrio</em> species, but its role in <em>V. harveyi</em> is not well defined. In this study, we deleted <em>VxrB</em> in a virulent <em>V. harveyi</em> strain and named the mutant VHΔ<em>VxrB</em>. We compared it with the wild-type strain (W-VH) using <em>in vitro</em> assays, gene expression analysis, and infection and vaccination tests in pearl gentian grouper. Deleting <em>VxrB</em> did not change cell morphology by Gram staining or scanning electron microscopy. However, VHΔ<em>VxrB</em> grew more slowly and showed reduced hemolytic activity, while swarming motility increased. RT-qPCR showed that <em>VxrB</em> deletion reduced expression of several virulence-associated genes and lowered expression of the type VI secretion system (T6SS) genes <em>hcp</em> and <em>vgrG</em>. In fish, VHΔ<em>VxrB</em> was less virulent than W-VH, with an LD50 of 1.45 × 10⁸ CFU/mL compared with 4.88 × 10⁷ CFU/mL for the wild type. We also tested VHΔ<em>VxrB</em> as a live attenuated vaccine. Vaccinated fish had higher survival after homologous challenge, with an RPS of 68.75%, and showed no obvious histopathological lesions. Vaccination increased spleen expression of <em>mhc-Iα</em>, <em>myd88</em>, and <em>il-10</em>. Together, these results show that <em>VxrB</em> supports virulence-related programs in <em>V. harveyi</em> and that VHΔ<em>VxrB</em> is a promising attenuated vaccine candidate for pearl gentian grouper.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111186"},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of dietary fermented sugar kelp (Saccharina latissima) on intestinal histology, antioxidant capacity, and immune-related biomarkers of post-smolt Atlantic salmon (Salmo salar).","authors":"Sahar Sartipiyarahmadi, Ingvild Lunderød Øverbø, Benjamin Costas, Lourenço Ramos-Pinto, Nina S Liland, Harald Sveier, Silje Steinsund, Tom Johnny Hansen, Øivind Strand, Jan Vidar Jakobsen, Antony J Prabhu Philip, Sofie C Remø","doi":"10.1016/j.fsi.2026.111179","DOIUrl":"10.1016/j.fsi.2026.111179","url":null,"abstract":"<p><p>Brown seaweeds such as sugar kelp (Saccharina latissima) are rich in bioactive compounds with potential health benefits for fish. This study evaluated the effects of dietary fermented sugar kelp (FSK) on mid-intestinal histology, antioxidant biomarkers, and immune response in post-smolts Atlantic salmon (Salmo salar). A total of 975 fish (204 ± 37 g) were allocated across 15 tanks and fed one of five isonitrogenous (≈45% crude protein) diets containing 0-4% FSK for 10 weeks. Plasma, liver, muscle, and mid-intestine samples were analyzed for histological and biochemical parameters at the end of the trial. FSK inclusion up to 4% had no adverse effects on mid-intestinal morphology or signs of inflammation. Liver antioxidant capacity was modulated, with significantly higher glutathione (GSH) concentrations and lower malondialdehyde (MDA) levels in FSK 4%-fed groups compared to the control. However, no changes were observed in muscle or intestinal antioxidant levels. Immune-related parameters were also modulated: plasma lysozyme activity doubled at 1% and 3% FSK, and plasma bactericidal activity more than doubled at 3% FSK compared to the control group. Antiprotease activity increased dose-dependently, although plasma peroxidase activity and IgM levels declined slightly. Overall, dietary FSK up to 4% does not alter mid-intestine morphology or induce inflammation. Additionally, it shows potential functional effects in fish, including the modulation of hepatic antioxidant capacity and innate-immune mechanisms, particularly antibacterial effects. These findings support further investigation into the functional use of seaweed-derived ingredients in aquafeeds. The study design and main findings are provided in a graphical abstract.</p>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":" ","pages":"111179"},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms underlying differential utilization of carbohydrates from diverse structures and sources in Nile tilapia (Oreochromis niloticus): Insights from glycolipid metabolism, protein deposition and liver health","authors":"Meng-Ting Liu ,&nbsp;Chen-Chen Wu ,&nbsp;Si-Miao Pan ,&nbsp;Samwel Mchele Limbu ,&nbsp;Yu-Yang Liang ,&nbsp;Ying-Man Yu ,&nbsp;Fang Qiao ,&nbsp;Mei-Ling Zhang ,&nbsp;Zhen-Yu Du ,&nbsp;Yuan Luo","doi":"10.1016/j.fsi.2026.111187","DOIUrl":"10.1016/j.fsi.2026.111187","url":null,"abstract":"<div><div>The proper structure and source of dietary carbohydrates are vital for farmed fish health, yet their metabolic responses to varied carbohydrates are not clear. To explore fish metabolic responses to varied carbohydrates, Nile tilapia was fed with five different carbohydrate diets for eight weeks. The results showed that polysaccharides significantly enhanced the growth performance of fish (<em>P</em> &lt; 0.05). The fish fed with polysaccharides showed lower serum glucose, pyruvate and lactate, while their liver glucose uptake and catabolic capacity were significantly enhanced (<em>P</em> &lt; 0.05). Furthermore, the PDK4-PDHE1α axis, which linked glycolysis to the TCA cycle, exhibited a stronger response to polysaccharides, particularly in the corn starch group. The total lipid of the whole fish, as well as the TG in the liver and serum, were significantly elevated in the fish fed with wheat and tapioca starch (<em>P</em> &lt; 0.05). Additionally, the fish fed with wheat and tapioca starch exhibited a significant higher expression of PPARγ, DGAT and FAS (<em>P</em> &lt; 0.05). The serum levels of AST and ALT, as well as the liver MDA content, significantly decreased in the fish fed with polysaccharides (<em>P</em> &lt; 0.05). Meanwhile, the expression levels of pro-inflammatory (TNFα and IL12) and apoptosis (caspase8 and caspase9) -related genes in the liver were significantly downregulated, while the antioxidant capacity markedly increased (<em>P</em> &lt; 0.05). The total protein of the whole fish, muscle protein content, and muscle fiber diameter of fish fed polysaccharides were significantly increased, particularly in the corn starch group (<em>P</em> &lt; 0.05). Furthermore, the fish fed with polysaccharides exhibited stronger mTOR signaling response and higher protein synthesis capacity in the muscle, particularly in the corn starch group (<em>P</em> &lt; 0.05). This study demonstrated that the PDK4-PDHE1α axis and mTOR exhibit a stronger response to polysaccharides, boosting carbohydrate breakdown and protein synthesis for growth. PPARγ responds more robustly to wheat and tapioca starch, facilitating the esterification of free fatty acids into TG, which reduced lipid toxicity and maintained liver health.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111187"},"PeriodicalIF":3.9,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-cell RNA-seq reveals cellular dynamics and emergency hematopoiesis in banana shrimp Penaeus merguiensis hemocytes upon Yellow Head Virus infection","authors":"Keiichiro Koiwai ,&nbsp;Phattarunda Jaree ,&nbsp;Kanjanaporn Nanthajak ,&nbsp;Masachika Harada ,&nbsp;Hiroki Kusaka ,&nbsp;Ammara Sinprasertporn ,&nbsp;Hajime Yuasa ,&nbsp;Kayo Konishi ,&nbsp;Reiko Nozaki ,&nbsp;Hidehiro Kondo ,&nbsp;Jumroensri Thawonsuwan ,&nbsp;Kunlaya Somboonwiwat ,&nbsp;Ikuo Hirono","doi":"10.1016/j.fsi.2026.111178","DOIUrl":"10.1016/j.fsi.2026.111178","url":null,"abstract":"<div><div>As global aquaculture of penaeid shrimp expands, the banana shrimp (<em>Penaeus merguiensis</em>) has gained attention as a promising sustainable alternative to the non-native <em>P. vannamei</em>. However, its cellular immune response to major pathogens like yellow head virus (YHV) remains poorly understood, limiting effective disease management. In this study, we established a comprehensive reference transcriptome for <em>P. merguiensis</em> by integrating data from 13 major tissues and conducted single-cell RNA sequencing (scRNA-seq) on hemocytes under normal and YHV-infected conditions. We identified eight distinct hemocyte clusters (cluster 0–7) and demonstrated that YHV infection triggers a massive turnover of the hemocyte landscape. Specifically, mature immune-active clusters expressing <em>anti-lipopolysaccharide factor</em>s (<em>ALF</em>s) and <em>lysozyme</em>s were significantly depleted, likely due to virus-induced apoptosis. Conversely, a marked expansion of an immature hemocyte progenitor cluster (cluster 4) was observed, indicating a host-driven emergency hematopoiesis response. Our analysis further revealed that global transcriptional changes are heavily biased by these composition shifts: 30.7% of the total 114 globally regulated genes were identified as cluster-specific markers. These findings provide a high-resolution model of crustacean immune dynamics and highlight the necessity of single-cell analysis for accurately deciphering host-pathogen interactions.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111178"},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146118298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indole-3-propionic acid enhances intestinal health and protects against Aeromonas hydrophila infection in high-fat-diet fed Nile tilapia (Oreochromis niloticus)","authors":"Fei-Fei Ding ,&nbsp;Shi-Qi Deng ,&nbsp;Yu-Xin Fan ,&nbsp;Shi-Yan Qiao ,&nbsp;Gang Wang","doi":"10.1016/j.fsi.2026.111180","DOIUrl":"10.1016/j.fsi.2026.111180","url":null,"abstract":"<div><div>High fat diet (HFD) is widely utilized in aquaculture to promote growth and feed protein retention, but overconsumption of fat will induce systemic metabolic disorders of fish accompanied by impaired intestinal health and lower pathogen resistance. Indole-3-propionic acid (IPA) has been widely reported to enhance intestinal health in mammals. Our previous study has proven that IPA alleviated lipid metabolism disorder and lipotoxic liver injury in Nile tilapia (<em>Oreochromis niloticus</em>). However, it remains unclear whether IPA can sustain fish intestinal health. In this study, 540 Nile tilapia (2.53 ± 0.02 g) were allotted in 6 groups with 3 tanks each and fed with control diet or high-fat diet supplemented with different levels of IPA (0, 20, 40, 80, 160 mg/kg) respectively. After 8 weeks, it was observed that 80 mg/kg IPA proved the most beneficial for decreasing intestinal myeloperoxidase (MPO) enzyme activity and improving the survival rate of Nile tilapia infected with <em>Aeromonas hydrophila</em>. Dietary IPA restored intestinal barrier integrity impaired by HFD and increased the genes expression of tight junctional proteins (tjps), such as zona occludens 1 (<em>zo-1</em>) and <em>occludin</em>. The results showed that dietary IPA effectively mitigated HFD caused intestinal oxidative stress, manifesting as lower levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and higher activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Dietary IPA promoted the gene and protein expression of aryl hydrocarbon receptor (Ahr) in intestine. Further investigation suggested that IPA could activate Ahr and affect nuclear factor-E2-related factor 2 (NRF2) signaling to reduce oxidative stress. Moreover, IPA might suppress enteritis by inhibiting the Ahr-mediated nuclear factor kappa light-chain-enhancer of activated B (NF-κB) signaling pathway. These findings indicated that IPA has the potential to improve intestinal health and pathogen resistance in HFD-fed fish, offering crucial insights for the application of innovative additives in aquatic feeds.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111180"},"PeriodicalIF":3.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146118308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and expression profile of serotonin receptors in the developmental stages and hemocytes of the Pacific oyster (Crassostrea gigas)","authors":"Minhui Xu ,&nbsp;Miren Dong ,&nbsp;Xiaolong Gao ,&nbsp;Wei Wu ,&nbsp;Lingling Wang ,&nbsp;Chunlin Wang","doi":"10.1016/j.fsi.2026.111148","DOIUrl":"10.1016/j.fsi.2026.111148","url":null,"abstract":"<div><div>Serotonin (5-hydroxytryptamine, 5-HT), a pleiotropic biogenic monoamine, modulates immune response through interactions with its distinct receptors (5-HTRs). In this study, thirteen 5-HTRs were identified in the Pacific oyster (<em>Crassostrea gigas</em>) to elucidate their functions in immune response to <em>Vibrio</em> stimulation. Except for the unique ligand-gated cation channels (<em>Cg</em>5-HTR3A-like), the other twelve 5-HTRs (Two <em>Cg</em>5-HTR, <em>Cg</em>5-HTR-like, <em>Cg</em>5-HTR1, <em>Cg</em>5-HTR1A-like, <em>Cg</em>5-HTR1B, <em>Cg</em>5-HTR1B-like, <em>Cg</em>5-HTR2A-like, <em>Cg</em>5-HTR2B, <em>Cg</em>5-HTR4, <em>Cg</em>5-HTR5, and <em>Cg</em>5-HTR6) all belong to G protein-coupled receptor (GPCR) superfamily. Among those twelve 5-HTRs, most are non-canonical members lacking complete seven-transmembrane (7TM) domains; only <em>Cg</em>5-HTR2B and <em>Cg</em>5-HTR6 retain the canonical GPCR architecture. Ten conserved motifs were identified in oyster 5-HTRs, with motif 2 being universal across all receptors and motif 10 unique to <em>Cg</em>5-HTR3A-like, indicating subtype-specific divergence. Molecular docking revealed significant differences in binding affinity and residue interaction among <em>Cg</em>5-HTRs, with <em>Cg</em>5-HTR6 exhibiting the highest binding affinity for 5-HT. Analysis across developmental stages revealed that <em>Cg</em>5-HTR1A-like transcripts were enriched in early gastrula, gastrula and trochophore, <em>Cg</em>5-HTR4, <em>Cg</em>5-HTR1B, and <em>Cg</em>5-HTR-like enriched specifically in the D-shape stage, while <em>Cg</em>5-HTR2B and <em>Cg</em>5-HTR1 transcripts enriched during the pediveliger, spat, and juvenile stages. Furthermore, <em>Cg</em>5-HTR-like and <em>Cg</em>5-HTR1 were primarily expressed in granulocytes, <em>Cg</em>5-HTR1A-like and <em>Cg</em>5-HTR2B in agranulocytes, and <em>Cg</em>5-HTR6 and <em>Cg</em>5-HTR1B in semi-granulocytes. Crucially, following secondary <em>Vibrio splendidus</em> stimulation, the expression levels of <em>Cg</em>5-HTR-like, <em>Cg</em>5-HTR1, <em>Cg</em>5-HTR1A-like, <em>Cg</em>5-HTR1B and <em>Cg</em>5-HTR2B mRNA in hemocytes upregulated significantly, indicating their potential role in immune priming. These findings suggested the potential mechanisms of 5-HTRs in regulating the immune response of hemocytes in <em>C. gigas</em>, which offered insights into the evolutionary conservation and immunoregulation divergence of these receptors in invertebrates.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"172 ","pages":"Article 111148"},"PeriodicalIF":3.9,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146100076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}