Search Results (562)

Broodstock nutrition is a key determinant of reproductive output in marine fishes because lipids support yolk formation, embryonic development, and early larval viability. However, the allocation of lipid classes between fertilized eggs and the egg envelope (chorion) remains poorly characterized for many tropical species. In this study, we performed a comparative lipidomic analysis of dechorionated fertilized egg contents and isolated chorion from three tropical marine fishes (Trachinotus ovatus, Platax teira, and Plectropomus leopardus) using UHPLC–Q Exactive Orbitrap MS/MS. Multivariate analyses revealed clear tissue- and species-specific lipid patterns. Dechorionated eggs were enriched in energy-storage lipids, dominated by triacylglycerols and essential polyunsaturated fatty acids, whereas chorion tissues contained higher levels of structural and signaling lipids, including phosphatidylinositols and sphingolipids. Each species exhibited a distinct lipid signature, with T. ovatus characterized by higher secosteroids and free fatty acids, P. teira by glycerophosphoethanolamines and phosphoinositols, and P. leopardus by abundant triradylglycerols. Pathway enrichment highlighted glycerophospholipid metabolism and sphingolipid signaling as prominent processes during early development. These findings clarify lipid partitioning between dechorionated fertilized egg contents and the chorion and provide a biochemical rationale for optimizing species-specific broodstock diets to enhance egg quality in tropical marine aquaculture. Full article

The accumulation of heavy metals in fish tissues is widely recognized as an indicator of aquatic environmental pollution, and the analysis of their content provides a basis for assessing ecological risk and the safety of aquatic food. The European eel (Anguilla anguilla) is a species frequently used as a bioindicator in environmental studies due to its wide geographic distribution, long life cycle, and high capacity for bioaccumulation of heavy metals in various tissues. The aim of this study was to assess the variation in the accumulation of heavy metals, i.e., mercury (Hg), lead (Pb), arsenic (As), and cadmium (Cd), in the tissues (muscle, liver, gonads, and gills) of European eels caught in two locations in Polish inland waters. The obtained results showed significant differences both in the concentration levels of individual elements and in their co-occurrence in the examined tissues. The statistical methods used, including correlation analysis, heat maps, and principal component analysis (PCA), allowed for a comprehensive assessment of the relationships between metals and the identification of factors differentiating the studied populations. The obtained results clearly indicate that fish residing in similar environments for long periods exhibit significant differences in heavy metal content in various fish tissues. Fish obtained from environments with potentially higher levels of heavy metal inputs, such as the Oder River EMU compared with the Vistula River EMU, showed higher levels of heavy metal accumulation in tissues. This study also found that the concentration of heavy metals tested did not exceed the safe standards for human fish consumption. Full article

Background: Cancer-associated fibroblasts (CAFs) are key mediators of metastatic progression in non-small cell lung cancer (NSCLC). Fibroblast activation protein (FAP) serves as the hallmark of CAF activation. However, the upstream regulation of FAP remains elusive, limiting stroma-targeted therapy development. Methods: ⁶⁸Ga-FAP inhibitor (FAPI)-04 PET/CT imaging was performed on 61 NSCLC patients to evaluate the clinical significance of FAP. CAFs and normal fibroblasts (NFs) were isolated from patient tissues. Bioinformatic analysis and qRT-PCR were employed to screen and validate miRNAs. Functional assays (CCK-8, collagen contraction, wound healing, transwell co-culture) were utilized to investigate the role of miR-624-5p in regulating fibroblast activation and the effects on the metastatic potential of NSCLC cells. The targeting relationship between miR-624-5p and FAP was validated using FISH, dual-luciferase assay, and Western blotting. Results: ⁶⁸Ga-FAPI-04 uptake was higher in advanced NSCLC (p < 0.001) and correlated with tumor size, lymph node metastases, and distant metastases (p < 0.05). Isolated primary CAFs significantly enhanced the migration and invasion of A549 and PC9 cells compared to NFs (p < 0.001). We identified miR-624-5p as a significantly downregulated miRNA in CAFs (p < 0.001). Functionally, miR-624-5p overexpression inhibited CAF proliferation and collagen contraction (p < 0.01) and reduced the proliferation, migration, and invasion capabilities of A549 and PC9 cells (p < 0.001). Mechanistically, miR-624-5p bound to FAP mRNA and negatively regulated FAP expression (p < 0.001), thus suppressing CAF activation and tumor metastasis. Conclusions: Our findings establish miR-624-5p as a novel upstream regulator that suppresses FAP expression, consequently inhibiting CAF activation and its pro-metastatic function. Targeting the miR-624-5p/FAP axis represents a promising therapeutic strategy for NSCLC metastasis. Full article

This study aimed to investigate the response mechanisms of liver and gill tissues in mandarin fish (Siniperca chuatsi) at the histological, apoptotic, and gene expression levels during the weaning process from live prey to artificial feed. By analyzing fish samples at different domestication stages (D0, D7, D14), the results revealed that: (1) Histologically, the gill filaments exhibited shortening and thickening post-domestication, while the liver showed increased vacuolation; (2) apoptosis detection (TUNEL assay) and analysis of apoptosis-related gene (Bax/Bcl-2) expression indicated that the gill tissue experienced a significant increase in apoptosis at the mid-domestication stage (D7), which returned to baseline levels later (D14), whereas hepatic apoptosis showed no significant changes throughout the process; (3) transcriptome sequencing identified 3405 and 881 differentially expressed genes (DEGs) in the liver and gill tissues, respectively, and the significantly enriched pathways were steroid biosynthesis in the liver and alanine, aspartate, and glutamate metabolism in the gills. The apoptosis pathway was also significantly enriched in both tissues. GO analysis further indicated that the DEGs were primarily associated with metabolic processes, oxidative stress, and cell apoptosis. In conclusion, artificial feed domestication induces adaptive changes in the tissue structure and molecular profiles of the gill and liver in mandarin fish. The gill response to dietary transition is more rapid and characterized by a reversible apoptotic process, providing a theoretical foundation for understanding the stress mechanisms associated with domestication and promoting healthy aquaculture practices for this species. Full article

This study investigated the effects of chronic MC-LR exposure (0 μg/L [Control], 1 μg/L [M1], 3 μg/L [M3], 10 μg/L [M10], and 30 μg/L [M30]) on the muscle nutrient composition, meat quality, and muscle proteomic profile of Nile tilapia (Oreochromis niloticus). In the high-dose group (M30), MC-LR exposure compromised the muscle antioxidant status of Nile tilapia, resulting in reduced meat quality, as evidenced by decreased pH value and water-holding capacity, elevated lipid/protein oxidation, and altered texture parameters (shear force and fragmentation index). Proteomic analysis further revealed a downregulation of proteins associated with ribosomes, suggesting an impairment of muscle protein synthesis in the M30 group. Moreover, despite chronic exposure, only low levels of MC-LR accumulated in the muscle tissue, indicating a negligible health risk to consumers. Collectively, these findings offered valuable insights into the impact of environmental MC-LR contamination on fish muscle quality and nutritional value. Full article

Background: Ewing’s sarcoma (EwS) is a pediatric bone and soft tissue cancer driven by the oncogenic fusion protein EWS::FLI1. Currently, EwS lacks targeted therapies, necessitating the identification of novel regulatory mechanisms. While the role of microRNAs and long non-coding RNAs has been explored in EwS, the presence and functional significance of circular RNAs (circRNAs) in EwS is not reported. This is the first study to report the presence and role of oncogenic circRNA, circZNF609 in EwS tumor progression. Methods: Expression of circZNF609 was validated in 5 different EwS cell lines using qPCR. Cellular localization of circZNF609 was identified using circFISH. Functional assays for proliferation, migration and apoptosis were performed in wild type and circZNF609 knocked down (KD) cell lines to confirm its oncogenic role. The impact of circZNF609 on EWS::FLI1 protein levels was confirmed using western blots, immunofluorescence, and polysome fractionation. Mechanistic insights were gained utilizing bioinformatic, dual-luciferase reporter assays, rescue experiments, and microscopy to identify and validate the circRNA-miRNA-mRNA regulatory axis. Results: We report the first identification of circZNF609 in EwS, demonstrating that its expression is EWS::FLI1-dependent. Functional analysis reveals that circZNF609 promotes cell proliferation and metastasis while inhibiting apoptosis. Mechanistically, circZNF609 acts as a molecular sponge for miR-145-5p. By sequestering this miRNA, circZNF609 prevents the translational repression of EWS::FLI1, thereby sustaining oncogenic signaling. Conclusions: These findings identify circZNF609 as a novel post-transcriptional regulator of EWS::FLI1 and establish its critical role in EwS pathogenesis. Our results suggest that targeting the circZNF609/miR-145-5p/EWS::FLI1 axis may offer a promising therapeutic strategy for EwS. Full article

The greater amberjack (Seriola dumerili) is an economically important marine species that is prone to bacterial infections, resulting in high mortality rates and substantial economic losses. In this study, a virulent bacterial strain, Vh-2, was isolated from diseased greater amberjack and identified as Vibrio harveyi. Experimental infections caused high mortality and severe splenic damage characterized by tissue necrosis, abnormal pigment deposition, cellular disintegration, and extensive immune cell infiltration. A virulence gene analysis revealed that Vh-2 harbored multiple virulence-associated genes such as toxR, toxS, vhpA, vhpB, vhhA, vhhB, luxR, and pap6. Antibiotic susceptibility testing demonstrated ampicillin resistance but sensitivity to ceftriaxone, florfenicol, and meropenem. Transcriptomic profiling of infected spleens identified 396 differentially expressed genes (DEGs) compared to the control group, of which 293 were upregulated and 103 were downregulated. A functional enrichment analysis indicated that these genes were primarily involved in cell cycle regulation, DNA repair, metabolic processes, and immune-related pathways. These findings enhance our understanding of V. harveyi pathogenesis and immune responses of S. dumerili and provide new insights into the prevention and control of V. harveyi infections in marine fish. Full article

Amid the intensifying global mandate for sustainable aquafeed strategies, this study investigates the functional efficacy and biochemical implications of black soldier fly larvae oil (BLO), extracted via recently approved patent method depending on cold-aqueous process, as a substitute for conventional fish oil (FO) in zebrafish (Danio rerio) diets. The refined extraction technique, representing an advancement over traditional aqueous methodologies, was engineered to selectively preserve bioactive lipid fractions while minimizing environmental footprint and processing residues. Over a 28-day feeding period, adult zebrafish were allocated into triplicate groups and fed diets comprising 0%, 50%, and 100% substitution of FO with BLO and growth, lipid composition, and dietary fatty acid profiles of both diets and flesh were rigorously evaluated. Zebrafish fed the BLO₁₀₀ diet exhibited the most pronounced somatic growth (2.47 ± 0.01 g), significantly elevated specific growth rates (3.88 ± 0.82% day⁻¹), and the most efficient feed conversion, without compromising survival. Flesh lipid analysis revealed a substantial enrichment in saturated fatty acids—most notably lauric acid (C12:0)—corresponding to increasing dietary BLO levels. Although dietary EPA and DHA levels were reduced, DHA concentrations in fish tissues remained comparable to those of the control group, indicating a compensatory capacity mediated by endogenous elongation and desaturation pathways. These findings substantiate the dual potential of BLO as both a nutritionally viable lipid source and a vector for enhancing aquafeed sustainability. The cold-aqueous extraction method demonstrated here underscores a pivotal advancement in green lipid processing, aligning oil quality with ecological stewardship. This integrative approach not only reinforces BLO’s candidacy as a strategic fish oil substitute but also delineates a pathway toward scalable, species-adapted feed innovation. Future investigations should prioritize the modulation of fatty acid profiles through dietary and extraction optimization to fully realize the translational potential of insect-derived lipids in aquaculture. Full article

The Mediterranean Sea is recognized for its high biodiversity but is also a hotspot for pollution. In this study, fish samples of four native marine species were collected from wild catches to determine contaminants such as Anisakis parasites and heavy metals, including nickel, lead, copper, zinc, and chromium, within local marine fish species. The detection of Anisakis parasites was performed by a visual inspection and a digestion method. Metal analysis was carried out on skin, muscle, viscera, and bones of fish, using Microwave Plasma-Atomic Emission Spectroscopy. This study demonstrated that Boops boops was the least infested species by Anisakis parasite, while Scomber colias was the most infested, with Sardinella aurita and Trachurus trachurus showing a lower infestation rate. Pearson correlation statistics revealed that infestation correlated with fish size but not with maturity or sex. Principal component analysis (PCA) demonstrated that the carnivorous species were more prone to Anisakis infestation than the omnivorous species. The maximum levels of copper, nickel, chromium, lead, and zinc content in fish tissues were 13.2 ± 0.11, 19.5 ± 0.02, 19.9 ± 0.01, 28.8 ± 0.09, and 184.87 ± 0.63 µg/g, respectively. PCA revealed that heavy metal contamination does not discriminate between fish species and sex, as opposed to tissue type and location of catch. Some metals, such as zinc and lead, seem to accumulate more in muscle rather than the other tissues. These findings indicate that Anisakis infestation and heavy metal analysis should be monitored and extended beyond the current EU requirements. Full article

Over the past few decades, the population of cod in the Eastern Baltic has faced numerous challenges due to environmental changes, overfishing, and predation, as well as the effects of infection by third-stage larvae of the Anisakidae parasite in the liver. The aim of this study was to estimate the prevalence and infection level of Anisakidae nematodes in the Eastern Baltic cod stock over a five-year period and analyze the effect of infection on cod health condition. A total of 1946 samples of the Eastern Baltic cod (Gadus morhua) were collected and tested for the presence of Anisakidae nematode larvae. All nematodes found in livers were identified as Anisakidae with an overall prevalence of 30.9%, a mean infection density of 0.8 (median 0.4) nematodes per gram of liver tissue, and a range of 0.01–29.2 nematodes per gram. The prevalence of infection tended to increase with the age of the fish. In multivariate analysis, increasing infection intensity decreased the odds of cod having good Fulton’s and Clark’s condition scores and a hepatosomatic index (HSI) above the population average. While our study shows a clear Anisakidae effect on Fulton’s and Clark’s condition scores and the HSI, these indicators could also be influenced by other environmental, physiological, and pathological factors. Full article

This study examined the effects of dietary aniseed, thyme, and basil essential oils (EOs) on growth, health, and tissue integrity of common carp (Cyprinus carpio) reared in a recirculating aquaculture system (RAS). Juvenile carp (102 ± 2.8 g) were fed for 12 weeks four isonitrogenous diets: a control and three diets supplemented with 0.2% aniseed (V1), thyme (V2), or basil (V3) oils. Growth performance was not significantly affected (p > 0.05). Flesh biochemical composition improved, with higher protein in V1 (17.85 ± 0.22%) and lower fat in V3 (1.78 ± 0.21%) compared to the control. Hematological parameters and antioxidant enzymes (SOD, CAT, GPx) indicated enhanced immune and oxidative status, while MDA (malondialdehyde) levels decreased. SOD activity increased in treated groups, reaching 4.329 U mg⁻¹ protein in muscle and 4.908 U mg⁻¹ protein in liver in V2, compared to 2.775–3.677 U mg⁻¹ protein (muscle) and 3.508–4.349 U mg⁻¹ protein (liver) in controls. CAT activity was highest in the same group 57.045 U mg⁻¹ protein versus 31.403 U mg⁻¹ protein in controls. Microbiological assessment revealed reduced total aerobic bacteria and Enterobacteriaceae counts in EO-fed fish. Histological analysis showed healthier hepatic and intestinal structures, reduced vacuolation, intact epithelium, and abundant goblet cells in EO-treated groups. Full article

Volcanic eruptions can mobilize naturally occurring toxic elements such as arsenic into surrounding ecosystems, contaminating soil, water, and food webs. Despite increasing evidence of arsenic enrichment in volcanic regions, comprehensive exposure assessments that integrate dietary and drinking water pathways remain limited, particularly in post-eruption contexts where baseline data are scarce. Following the 2020 Taal Volcano eruption, this study conducted a probabilistic risk assessment to quantify aggregate exposure to inorganic arsenic (iAs) among residents of Batangas, Philippines. A Monte Carlo simulation framework (10,000 iterations) integrated post-eruption environmental data on total arsenic in soil, lake water, drinking water and clam tissues with modeled bioaccumulation and transfer factors for fish and major terrestrial crops. Two exposure scenarios, lower bound (50% iAs fraction) and upper bound (90% iAs fraction), were applied to capture uncertainty in arsenic speciation and bioavailability. Simulated iAs concentrations followed the order rice > corn > vegetables > root crops. Aggregate daily iAs doses averaged 3.0 ± 1.4 µg/kg bw/day (lower bound) and 4.0 ± 2.0 µg/kg bw/day (upper bound), with females showing slightly higher exposures and pregnant women exhibiting lower doses. Sensitivity analysis identified clam intake, rice intake, and iAs in rice, clams, and drinking water as dominant determinants of total exposure. All simulated individuals exceeded the U.S. EPA non-cancer reference dose (HQ > 1) and cancer risk benchmark (10⁻⁶–10⁻⁴), indicating substantial health concern. These findings highlight the urgent need for sustained environmental monitoring, arsenic speciation analyses, biomonitoring, and public health programs to guide evidence-based management in arsenic-affected volcanic regions. Full article

This study investigated the bioaccumulation of ciguatoxins (CTXs) in dusky grouper (Epinephelus marginatus) following dietary exposure to toxic fish flesh. Two feeding groups were established: group A (amberjack (Seriola spp.) and dusky grouper flesh) and group B (moray eel (Muraena spp. and Gymnothorax spp.) flesh). CTX-like toxicity was detected in muscle and liver of group A. Flesh toxicity progressively increased from the first sampling. In contrast, CTX activity was only detected in livers in group B. Liquid chromatography–mass spectrometry analysis revealed the presence of C-CTX1 in both groups, and the 17-OH-C-CTX1 analogue was exclusively observed in group A. Toxicity in the liver peaked at 10 weeks in experimental group A, but it showed a decline by the end of the experiment while increasing the storage of the toxin in muscle tissue. These findings demonstrate the differential bioaccumulation of CTXs in grouper flesh and liver, highlighting the potential role of the liver in metabolizing and/or detoxifying ciguatoxins. The efficacy of a combination of different techniques, including the cell-based assay (CBA) and liquid chromatography—low- and high-resolution mass spectrometry (LC-MS/MS and LC-HRMS), was demonstrated to confirm the presence of CTX analogues at very low levels. The results provide insights into CTX transfer and accumulation in marine food webs, underlining the need for further studies on toxin metabolism in predatory fish species. Full article

Nile tilapia (Oreochromis niloticus) is a globally important aquaculture species. However, intensive farming conditions increase the risk of bacterial diseases. Despite the fact that a considerable number of transcriptomic studies have examined host responses to single bacterial infections, comparative analyses conducted within a unified experimental framework remain scarce, limiting the understanding of pathogen-specific defence mechanisms. In this study, tilapia were experimentally infected with Streptococcus agalactiae, Escherichia coli, or Vibrio harveyi via thoracic injection. Head kidney tissues were collected at 48 h post-infection for RNA sequencing. The identification of differentially expressed genes (DEGs) was conducted utilising the edgeR, and the assessment of functional enrichment was facilitated through the implementation of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. A comparative analysis was conducted between the bacterial infection groups and the control group. The results of this analysis revealed the identification of 2930, 3328, and 4850 DEGs were identified in the S. agalactiae, E. coli, and V. harveyi infection groups, respectively. Integrated transcriptomic analysis, combining KEGG enrichment and expression profiling of key genes, revealed distinct response patterns across pathogens. The S. agalactiae infection predominantly activated innate immune signaling pathways, including Toll-like receptor, NOD-like receptor, cytokine–cytokine receptor interaction, and NF-κB pathways. In contrast, E. coli infection induced extensive metabolic reprogramming, notably in purine and pyrimidine metabolism, carbon metabolism, and amino acid biosynthesis. Meanwhile, an infection caused by V. harveyi resulted in mucosal and lysosomal defence responses, as evidenced by an increase in lysosome, phagosome, extracellular matrix–receptor interaction, and cell adhesion molecule pathways. Collectively, this study suggests that the head kidney of Nile tilapia employs pathogen-specific defence strategies rather than a uniform antibacterial response, providing one of the first transcriptomic comparisons of distinct bacterial infections in this species. These findings provide fundamental data and theoretical insights for elucidating immune mechanisms in teleost fish and for developing targeted prevention and control strategies in aquaculture. Full article

Transient receptor potential (TRP) channels play critical roles in animals in sensing diverse stimuli, especially environmental temperature. The teleost fish Nile tilapia (Oreochromis niloticus) cannot tolerate cold temperatures. In this study, we identified a total of 32 TRP genes in the tilapia genome. Based on analyses of gene structure and phylogenetic relationship, all tilapia TRP genes could be classified into six subfamilies, namely, TRPA, TRPC, TRPM, TRPV, TRPP, and TRPML. Comparative analysis showed that three TRP subfamilies—TRPC, TRPM, and TRPML—underwent an expansion in tilapia and other teleost fishes following three or four rounds of whole-genome duplication. In addition, expression profiling revealed that a large number of TRP genes were expressed in at least one tissue in adult tilapia. Notably, compared with normal growth temperature (28 °C), cold stress (10 °C) altered the expression of several TRPs in multiple tissues in adult tilapia, especially upregulating TRPC5 in the brain and TRPM7 in the gill. Collectively, these findings provide new insight into the phylogeny of TRP genes in animals and lay the foundation for further investigation into the roles of TRP channels in cold sensitivity in tilapia. Full article