Search Results (3,354)

Bacterial diseases caused by Flavobacterium covae (Fc), Vibrio harveyi (Vh), Vibrio vulnificus (Vv) and Photobacterium damselae (Pd) seriously constrain Asian seabass aquaculture. Here we dissect the mucosal immune mechanisms engaged by a five-month sequential vaccination strategy that combines nanoemulsion immersion priming with multivalent oral hydrogel boosting. Juvenile seabass were vaccinated, then challenged with F. covae by freshwater immersion and with a Vibrio–Photobacterium (Vh/Vv/Pd) mix by immersion or intraperitoneal injection. Gills were sampled after immersion challenges and intestine after injection, and profiled by RNA sequencing and label-free quantitative proteomics, with selected genes validated by RT-qPCR. Principal component analysis showed clear separation of vaccinated and control fish in all tissues and challenges, indicating a strong and coherent transcriptional reprogramming. Vaccination markedly increased the number of upregulated genes, with Gene Ontology enrichment revealing dominant signatures of ribosome biogenesis, RNA processing, lysosomal organization and immune response. KEGG analysis highlighted cytokine receptor interaction; NOD and Toll-like receptor signaling; oxidative phosphorylation; and phagosome, lysosome and cell adhesion molecule pathways, consistent with heightened antimicrobial readiness. Volcano plots and focused heatmaps showed strong induction of interferon-stimulated genes, cytokines and chemokine receptors, complement components, macrophage mannose receptor, epithelial barrier mediators and numerous immunoglobulin transcripts, with tissue- and challenge-specific patterns. Proteomics corroborated these trends, demonstrating a higher abundance of immunoglobulin heavy chains, complement proteins, cathepsins, heat shock and redox chaperones, ribosomal proteins and cytoskeletal and adhesion regulators in vaccinated mucosae. Integrated pathway mapping linked endothelial adhesion molecules and leukocyte integrins with T cell costimulation networks and an intestinal immune network for immunoglobulin production, including enhanced pIgR-mediated transcytosis. Overall, the sequential vaccination regimen was associated with coordinated transcriptomic and proteomic signatures related to epithelial responses, innate immunity, and humoral immune functions across gill and intestinal tissues. These molecular patterns were accompanied by improved survival following bacterial challenge; however, the present data do not directly demonstrate the functional activity of the inferred immune mechanisms in Asian seabass. Full article

Land-based Indigenous food practices are integral to cultural identity and ancestral knowledge, and provide medicine for health and wellbeing. We surveyed Indigenous-specific grey literature, guided by Elder knowledge, from public information sources to identify the scope of Indigenous traditional foods in Canada and how food use aligned with major food groups. We analyzed extracted data using summary statistics and graphical display. We identified 96 resources reporting 401 distinct food items incorporated into Indigenous food practices across Canada. Prevalent food groups were meat/proteins (39%), vegetables (20%), berries/fruits (12%), and a mixed group (21%); grains were rarely reported (1%). We found 28 unique plant foods reported to have multiple uses. Across sources, the top 15 most common food items were various berries, fish and wild game. The total count of food items and diversity with food groups categories varied by Indigenous group and region. This research documents the breadth and depth of traditional Indigenous food knowledge throughout Canada, demonstrating a consumption pattern focused on wild meat, berries and foods from plant and tree leaves, roots and stems. This overview of Indigenous food knowledge can support Indigenous individuals and communities, researchers and healthcare providers to improve health and wellbeing of Indigenous people. Full article

Lactococcosis is an important bacterial disease affecting farmed fish worldwide and is primarily associated with Lactococcus garvieae, Lactococcus petauri, and Lactococcus formosensis. In Thailand, information on L. garvieae infection in tilapia remains limited, particularly regarding genome-based identification, virulence determinants, and antimicrobial resistance profiles. This study characterized two L. garvieae isolates, AAHM-LG2501 and AAHM-LG2509, recovered from a lactococcosis outbreak in cage-cultured Nile tilapia (Oreochromis niloticus) in Ubon Ratchathani province, Thailand. Both isolates exhibited typical phenotypic characteristics of L. garvieae, including Gram-positive cocci, alpha hemolysis, positive capsule staining, and positive carbohydrate fermentation. Whole-genome sequencing confirmed both isolates as L. garvieae, with genome sizes of approximately 1.95 Mb and a G + C content of 38.9%. Genome-based taxonomic analysis supported species identification based on dDDH and ANI values, and both isolates were assigned to sequence type ST95 and serotype I. Virulence factor analysis identified 288 virulence-associated genes representing 97 virulence factors across 14 functional categories. Capsule-associated genes were prominent, together with genes involved in heme uptake, adhesion, hemolysis, stress survival, biofilm formation, and host adaptation. Ten capsule biosynthesis genes, including cpsABCFGKO, cps4A, and cps4I, as well as LPxTG cell wall anchor protein genes, were detected. Antimicrobial susceptibility testing showed resistance to nalidixic acid, oxolinic acid, and oxacillin, while reduced inhibition zones were observed for enrofloxacin and sulfamethoxazole-trimethoprim. Genome analysis identified predicted antimicrobial resistance determinants, including lsaD, vanT, vanY, and mdtA. Resistance-associated protein variants were detected in gyrA and gyrB, suggesting that target alteration may contribute to fluoroquinolone resistance. Overall, this study provides genome-level evidence of virulence and antimicrobial resistance determinants in L. garvieae from Thai tilapia and highlights the importance of whole-genome sequencing for accurate diagnosis, epidemiological surveillance, and disease management in aquaculture. Full article

Infectious pancreatic necrosis (IPN) is a highly contagious viral disease that causes significant economic losses in the global salmon farming industry. Despite the widespread use of vaccines, outbreaks caused by infectious pancreatic necrosis virus (IPNV) continue to occur, even in genetically resistant fish populations. Therefore, the development of alternative vaccination strategies remains a priority for sustainable aquaculture. In this study, we developed a vaccine prototype based on the recombinant IPNV capsid protein VP2 loaded in alginate microparticles for immersion immunization. The VP2 protein was produced using the E. coli pET21b+ expression system and subsequently encapsulated in alginate by ionic gelation with calcium chloride. The immunogenic potential of the VP2-MP formulation was evaluated in salmonids by quantifying specific antibody levels and analyzing the transcription of immune-related genes (ifn-α, ifn-γ, mx, and tbet). Fish immunized with VP2-MP showed induction of antiviral immune responses characterized by increased expression of ifn-γ and mx, together with detectable levels of specific antibodies against IPNV-VP2. Overall, these results indicate that alginate microparticles enhance the immunogenicity of the VP2 antigen and support the feasibility of immersion-based vaccination strategies against IPNV in salmonids. Full article

Maintaining sustainable production of healthy and nutritious food represents a major global challenge. Cultivated meat could reduce the environmental impact of livestock production, but it remains costly, largely due to the expense of fetal bovine serum, a common cell culture media supplement. Algal and cyanobacterial proteins, particularly phycobiliproteins, represent promising sustainable sources of potentially bioactive peptides that may contribute to the development of serum-reduced or serum-free culture media. This study investigated the potential of hydrolysates prepared using the protein extracts of the red alga Porphyra haitanensis and the cyanobacterium Arthrospira platensis as functional supplements for cell cultivation in a low-serum environment. Twelve hydrolysates were generated by treating protein extracts from Arthrospira platensis and Porphyra haitanensis with six proteolytic enzymes: pepsin, trypsin, chymotrypsin, subtilisin, thermolysin and proteinase K. The effects of these hydrolysates were studied in three cell models of mammalian (CHO-K1), avian (QM7), and fish (MACK1) origin. The effects of hydrolysates on cell viability, proliferation, and antioxidant activity were evaluated. A. platensis–chymotrypsin hydrolysate significantly improved QM7 cell viability compared to control in both 80% reduced-serum and tryptose phosphate broth conditions (p ≤ 0.0001). Additionally, peptide composition analysis and identification of amino acid sequences provided preliminary insights into potentially bioactive chromopeptides associated with the maintenance and promotion of cellular growth. Algae/cyanobacteria-derived hydrolysates positively regulated cell viability and proliferation in serum-reduced conditions, although effects were dependent on the algal species, enzymatic treatment, and cell type. These findings highlight their potential as sustainable supplements for alternative cell culture media. Full article

The microtubule-associated protein tau, encoded by the MAPT gene, serves as a major component of the neuronal cytoskeleton, facilitating the assembly, stabilization, and spatial organization of microtubules. Much of the work on tau has focused on the low-molecular-weight (LMW) isoforms abundantly expressed in the central nervous system (CNS) and their pathological aggregation in tauopathies. However, a different variant known as “Big tau”, present in the peripheral nervous system (PNS) and selective CNS regions has distinct structural and functional properties and offers a unique perspective on protein evolution. Big tau is characterized by the inclusion of a large, alternatively spliced insert termed exon 4a, which expands the protein’s projection domain by approximately 250 amino acids and increases the molecular weight to 90–110 kDa. The evolutionary trajectory of exon 4a presents a fascinating enigma that challenges conventional models of protein conservation. Across the vertebrate phylogeny, spanning from fishes, amphibians and birds to mammals, the primary amino acid sequence of exon 4a exhibits extreme divergence, often reaching background levels of identity when comparing distant classes. In contrast, the physical length of this domain remains remarkably stable, hovering around the 250-amino acid mark regardless of the species. This pattern suggests that the selective pressure acting on Big tau is not directed toward specific sequence motifs or functional domains, but rather toward the biophysical properties and physical dimensions of the domain. Here, we posit that exon 4a evolved as an essential molecular spacer optimized for the structural demands of long-projection neurons and high-caliber axons as well as a protective structure for the pathologic aggregation of tau. The paper examines the genomic architecture and biophysical identity underlying the stable-size and low sequence identity of exon 4a, presenting two evolutionary mechanisms as working hypotheses: a Prototype Model of neutral drift of an ancient insert, and an Independent Exonization of convergent recruitment of non-coding DNA by transposable elements or intron retention. Finally, we emphasize the need for additional experimental work in vitro and in vivo to resolve unanswered questions about the structure of the 4a exon, the physiological role Big tau and its potential insight into tauopathies therapeutics. Full article

Δ9 fatty acyl desaturase (Δ9 FAD) exerts important regulatory effects on fatty acid metabolism and membrane fluidity. However, its existence and the effects of nutritional regulation and ambient salinity on its expression are currently unknown in mud crab (Scylla paramamosain). In this study, the full cDNA sequence of Δ9 fad was isolated from the hepatopancreas of mud crab, which consists of 1468 bp and encodes a polypeptide of 347 amino acids. Sequence analysis revealed that the protein possessed typical characteristics of Δ9 FAD including three histidine-rich domains (HRLWSH, HRVHH and HNYHH), four transmembrane regions and three conserved motifs (FFSHMGW, QRKYY and PWDY). The results of tissue distribution indicated that the mud crab’s Δ9 fad expression was enriched in the hepatopancreas, with relatively lower levels found in the thoracic ganglia and cranial ganglia. Δ9 fad expression in the hepatopancreas was significantly influenced by dietary fatty acid profiles, and the replacement of fish oil with soybean oil markedly downregulated the transcriptional levels of hepatopancreatic Δ9 fad. Furthermore, the transcriptional levels of Δ9 fad were also significantly affected by ambient salinity. Under chronic salinity stress, the 7‰, 12‰, 17‰ and 22‰ salinity groups showed higher transcriptional levels of Δ9 fad in the hepatopancreas than the 27‰ salinity group, and the 7‰ salinity group significantly differed from the 27‰ salinity group. Under the acute salinity stress condition, the Δ9 fad transcriptional levels of muscle in the 14‰ and 4‰ salinity groups were higher than those in the 24‰ salinity group at 6 h and 12 h. By contrast, Δ9 fad in the hepatopancreas exhibited a slow response in reaction to low salinity stress, and only the 4‰ salinity group at 96 h had a higher value than the 24‰ salinity group. In addition, as for the starvation stress experiment, Δ9 fad expression in the starvation group was dramatically reduced when compared with the feeding group. These findings improve our understanding of the physiological roles of Δ9 fad and its regulatory mechanisms in crustaceans. Full article

Atlantic bonito (Sarda sarda) is a commercially important fish species with high nutritional value that is widely harvested along the Portuguese coast; however, it is highly susceptible to lipid oxidation and microbial deterioration during refrigerated storage. This study investigated the effectiveness of oregano oil (OO) emulsion coatings, with and without fish gelatin, to preserve quality and increase shelf life of Atlantic bonito fillets stored at 5 °C for 10 days. Emulsions were produced by high-intensity ultrasound treatment and subsequently, applied as surface coatings. Physicochemical, microbiological, and quality-related parameters, including pH, water activity, lipid oxidation, protein oxidation, color, and texture, were evaluated throughout storage. Water activity of the coated fillets remained stable (p > 0.05), whereas pH values remained below 6.0 until day 7. Coated fillets exhibited reduced oxidative deterioration and delayed microbial growth compared with uncoated fillets, with the 10% OO emulsion coating (OO₁₀) showing the higher effectiveness in maintaining color stability and limiting oxidation. The OO₁₀ emulsion coating with fish gelatin (FO₁₀) improved antimicrobial performance, although the gelatin matrix appeared to modulate the release of bioactive compounds from OO. Overall, OO emulsion coatings represent a promising natural preservation approach for extending the shelf life and maintaining the quality attributes of refrigerated fish products. Full article

The enzyme-treated soybean protein (ETSP) could improve their application as an ingredient and substitute for fishmeal (FM) in aquafeeds. In the present research, an eight-week feeding trial was carried out to investigate the effects of using ETSP as a particle substitution in FM on growth performance, serum biochemical indices, antioxidant, intestinal barrier integrity and relative mRNA expression levels in largemouth bass (Micropterus salmoides). A cohort of 450 fish (15.52 ± 0.04 g/fish) were randomly divided into five groups with five replacement levels of ETSP: 0, 12.5, 25.0, 37.5 and 50.0% (control, H2-12.5, H2-25.0, H2-37.5 and H2-50.0). Results showed that final body weight (FBW), weight gain (WG), and specific growth rate (SGR) reach the highest value, and the feed conversion ratio (FCR) reaches lowest in H2-25.0 group. The activities of total superoxide dismutase (T-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were remarkably increased by replacing FM with ETSP at certain level, while malondialdehyde (MDA) concentration significantly decreased (p < 0.05). Higher levels of total protein (TP) and albumin (ALB) as well as lower activity of aspartate aminotransferase (AST) were detected with ETSP replacement. Histological examination revealed that villus height in mid-intestine was the highest, while this factor in pyloric caeca was not affected. The activity of diamine oxidase (DAO) and the contents of D-lactate (D-Lac) and lipopolysaccharide (LPS) in serum were gradually decreased when replacing FM with ETSP in the diets. In addition, replacement of FM with ETSP at 25% improved intestinal barrier function by upregulating gene expression related to the tight junctions (occludin, claudins, ZO-1 and ZO-2) and anti-inflammatory cytokines (IL-10) while downregulating pro-inflammatory factors (IL-8 and TNFα). Moreover, proper amount of ETSP instead of FM can upregulate mRNA expression of LAT1, PEPT1 and PEPT2 in the intestine. In conclusion, at the fishmeal level used in the diet tested in the present study, 25% replacement is the most beneficial for juvenile largemouth bass. Full article

Hypoxia is a significant environmental and production-related stressor in Atlantic salmon aquaculture, yet the blood-based mechanisms underlying differential hypoxia tolerance remain poorly characterized. In this study, we examined hematological, biochemical, and transcriptional responses in Atlantic salmon parr classified as hypoxia-tolerant or hypoxia-susceptible following an acute progressive hypoxia challenge. Time to loss of equilibrium and dissolved oxygen concentration at loss of equilibrium were recorded. Blood samples were analyzed for hematological parameters, serum metabolites, and the expression of genes related to hypoxia signaling, glycolysis, oxidative stress, and immune regulation. Hypoxia-tolerant fish maintained equilibrium significantly longer than susceptible fish (Tolerant: 224 ± 18 min; Susceptible: 115 ± 24 min) and tolerated lower dissolved oxygen concentrations (Tolerant: 1.89 ± 0.09 mg L⁻¹; Susceptible: 2.55 ± 0.34 mg L⁻¹) before losing their ability to maintain equilibrium. Tolerance varied among families, while body weight was not significantly associated with time to loss of equilibrium. Acute hypoxia altered erythrocyte-related parameters, increased serum lactate (p < 0.0001), and reduced total protein (p = 0.0148) in both phenotypes. At the transcriptional level, tolerant fish exhibited higher expression of hif1α (p = 0.0012), k6pp (p = 0.0045) and il15 (p = 0.0159), along with reduced phd3 (p = 0.0317) expression, whereas susceptible fish showed increased anx1 expression. Taken together, our results showed that hypoxia tolerance in Atlantic salmon is associated with a coordinated blood response involving metabolic compensation and hypoxia-responsive signaling, supporting the use of blood as a practical tool for identifying resilient fish. Full article

Heat stress is one of the most prevalent and unavoidable environmental stressors in modern aquaculture and natural fishery ecosystems. With the intensification of global warming, the frequency, intensity, and duration of extreme heat events have increased substantially, progressively reducing the thermal safety margin of fish. As ectothermic vertebrates, fish rely heavily on ambient water temperature to maintain physiological functions and metabolic homeostasis. Elevated temperatures can induce profound metabolic reprogramming, characterized by suppressed protein deposition, enhanced lipid mobilization, and altered glucose metabolism, while simultaneously causing structural damage and functional dysfunction in critical organs and tissues such as the liver, intestine, gills, and reproductive system. Heat stress also activates the stress axis and oxidative stress responses, often leading to immunosuppression and disruption of antioxidant defenses, ultimately impairing growth performance, behavior, reproduction, and survival. This review focuses on fish and summarizes the major physiological injuries, molecular regulatory pathways, and adaptive strategies associated with heat stress under global warming. Comparative evidence from crustaceans and molluscs is used only where it helps clarify shared or divergent responses among aquatic ectotherms. Full article

The Taiwan loach (Paramisgurnus dabryanus ssp. Taiwan) is a popular cultured fish in southern China due to its rich nutritional content and rapid growth. Oxidative stress and homeostatic imbalance induced by low temperature are among the key factors restricting its large-scale aquaculture. Therefore, it is of great significance to investigate the oxidative stress damage and the adaptive mechanisms employed by this species in response to low temperature. In this study, the water temperature was lowered from 24 °C to 8 °C at a rate of 2 °C/h. Afterwards, the temperature was held at 8 °C for two durations: 12 h and 48 h. Antioxidant indices indicated that the Taiwan loach suffered from oxidative stress damage at the 12 h stage, but the antioxidant enzyme defense system was not fully activated. As the cold stress extended to 48 h, the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) increased significantly (p < 0.01). Histological observations revealed that the livers exhibited cellular vacuolation, sinusoid congestion and karyolysis under cold stress. Transcriptomic data revealed that the Taiwan loach underwent adaptive alterations in response to low temperature through diverse pathways. We speculate that, at low temperature, the Taiwan loach may, on the one hand, regulate lipid metabolism to maintain cell membrane fluidity and meet energy demands, and, on the other hand, reprogram protein synthesis and processing to avert the overaccumulation of misfolded proteins. In addition, it also adopts a strategy of lysine and polyamine accumulation. This study provides a novel theoretical basis for breeding cold-tolerant varieties of Taiwan loach and optimizing overwintering aquaculture management. Full article

Pediatric food allergy is an increasing public health challenge associated with severe allergic reactions, psychosocial burden, and healthcare inequalities. This study aimed to characterise molecular sensitisation patterns among Bulgarian children with suspected food allergy using component-resolved diagnostics and to evaluate family quality of life in a healthcare setting without access to epinephrine auto-injectors. A total of 1163 pediatric patients underwent molecular allergy testing using the ALEX² multiplex platform, while 90 caregivers completed structured quality-of-life questionnaires. A sensitisation threshold of >0.10 kUA/L was applied to maximise sensitivity for molecular profiling and co-sensitisation analyses. Tree nut allergens showed the highest sensitisation prevalence, predominantly involving Ana o 3, Pis v 1, Jug r 1, Cor a 9, and Cor a 14. Younger children showed a predominance of stable storage protein sensitisation, whereas older children more frequently demonstrated PR-10-associated cross-reactive profiles. Correlation analyses identified strong co-sensitisation clustering among phylogenetically related allergen families, particularly cashew-pistachio, walnut-hazelnut, mammalian milk, and fish allergens. Questionnaire responses revealed substantial psychosocial burden related to fear of anaphylaxis, chronic hypervigilance, restricted daily activities, and inadequate emergency preparedness. These findings highlight the importance of molecular risk stratification and underscore major unmet needs in pediatric food allergy management in Bulgaria. Full article

The growing demand for sustainable materials has renewed interest in replacing conventional petroleum-based wood adhesives with natural, environmentally friendly alternatives. This study evaluated the bonding performance of a conventional polyvinyl acetate (PVAc) adhesive and three natural adhesives—bone glue, fish glue and casein—for bonding European beech (Fagus sylvatica L.) wood of Greek origin. Bond quality was assessed according to ISO 6238:2018 by measuring shear strength and wood failure under ambient laboratory conditions (23 ± 2 °C) and after exposure to 50 °C for 15 days, simulating elevated temperatures that may occur in indoor environments. PVAc exhibited the most consistent bonding performance, whereas casein achieved shear strength comparable to that of PVAc, demonstrating its potential as a sustainable alternative for interior wood bonding. In contrast, bone glue and fish glue exhibited lower shear strength, greater variability in bond performance, and practical limitations associated with their shorter working and setting times. The percentage of wood failure generally followed the same trend as shear strength, confirming the relationship between bond quality and adhesive performance. Moderate thermal exposure did not significantly affect shear strength but resulted in lower wood failure percentages for the natural adhesives, whereas PVAc maintained, and slightly improved, its bond strength after thermal exposure. These findings demonstrate the promising performance of casein as a natural wood adhesive while highlighting the influence of moderate thermal exposure on the durability of natural adhesive systems intended for indoor applications. Full article

The largemouth bass (Micropterus salmoides) is persistently threatened by Micropterus salmoides rhabdovirus (MSRV) and largemouth bass ranavirus (LMBV), highlighting the need for combined immunization strategies. Here, a bivalent DNA vaccine pEGFP-G-MCP was constructed by concatenating the highly immunogenic fragments of MSRV glycoprotein (MSRV-G) and LMBV main capsid protein (LMBV-MCP) using a flexible linker peptide, and its immunogenicity and protective effect were systematically evaluated. Fish were immunized by intramuscular injection of 200 ng of plasmid on day 1, followed by a booster immunization on day 8. Blood and tissues were collected at 10, 20, and 30 d post-last immunization. The results showed that pEGFP-G-MCP immunization induced G- and MCP-specific antibodies and upregulated the expression of immunity-related genes. The bivalent vaccine achieved a relative percent survival (RPS) of 93.3% against MSRV and 90.0% against LMBV, which were higher than those of the monovalent vaccine groups. Additionally, the bivalent vaccine reduced viral mRNA and alleviated pathological damage in MSRV- or LMBV-infected fish. These results indicate that pEGFP-G-MCP confers immune protection against MSRV and LMBV, providing a foundation for combined prevention and control of MSRV and LMBV. Full article