Search Results (152)

Molecular chaperones, especially heat shock proteins (HSPs) have vital functions in cells’ responses to stress. Here, we cloned and sequenced the complete complementary DNA encoding HSP90 (MjHSP90) from the shrimp Marsupenaeus japonicus. The MjHSP90 cDNA comprised 3162 bp, including a 2172 bp coding region encoding a 724 amino acid-protein (predicted molecular mass = 83.12 kDa). Homology and phylogenetic analyses showed that MjHSP90 was highly conserved and most homologous to Litopenaeus vannamei HSP90. MjHSP90 is expressed in all tested tissues, with high expression in gill tissue and the hepatopancreas. Cold stress significantly upregulated MjHSP90 expression in the gill and hepatopancreas (p < 0.05). Following RNA interference knockdown of MjHSP90, the cold stress-related death rate of the shrimp increased significantly, accompanied by significantly upregulated expression of apoptosis-related genes Mjcaspase-3 and Mjbcl-2 (p < 0.05) and an increase in the number of apoptotic cells. The results indicated that MjHSP90 might play a pivotal role in the shrimp’s immune response to cold stress. Full article

Copper pyrithione (CuPT), an emerging biocide used in ship antifouling coatings, may accumulate in marine sediments and pose risks to non-target organisms. However, current research on CuPT toxicity remains limited. Litopenaeus vannamei, one of the world’s most important aquaculture shrimp species, relies heavily on its hepatopancreas for energy metabolism, detoxification, and immune responses. Due to their benthic habitat, these shrimps are highly vulnerable to contamination in sediment environments. This study investigated the toxicological response in the hepatopancreas of L. vannamei exposed to CuPT (128 μg/L) for 3 and 48 h. Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) fluorescence staining revealed increased apoptosis, deformation of hepatic tubule lumens, and the loss of stellate structures in the hepatopancreas after CuPT 48 h exposure. A large number of differentially expressed genes (DEGs) were identified by transcriptomics analysis at 3 and 48 h, respectively. Most of these DEGs were related to detoxification, glucose transport, and immunity. Metabolomic analysis identified numerous significantly different metabolites (SDMs) at both 3 and 48 h post-exposure, with most SDMs associated with energy metabolism, fatty acid metabolism, and related pathways. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of metabolomics and transcriptome revealed that both DEGs and SDMs were enriched in arachidonic acid metabolism, fatty acid biosynthesis, and glycolysis/gluconeogenesis pathways at 3 h, while at 48 h they were enriched in the starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, and galactose metabolism pathways. These results suggested that CuPT disrupts the energy and lipid homeostasis of L. vannamei. This disruption compelled L. vannamei to allocate additional energy toward sustaining basal physiological functions and consequently caused the accumulation of large amounts of reactive oxygen species (ROS) in the body, leading to apoptosis and subsequent tissue damage, and ultimately suppressed the immune system and impaired the health of L. vannamei. Our study elucidates the molecular mechanisms of CuPT-induced metabolic disruption and immunotoxicity in L. vannamei through integrated multi-omics analyses, providing new insights for ecological risk assessment of this emerging antifoulant. Full article

The Chinese mitten crab (Eriocheir sinensis) industry is currently facing the challenges of origin fraud, as well as a lack of precision and interpretability of existing traceability methods. Here, we propose a high-precision origin traceability method based on a combination of stable isotope analysis and interpretable machine learning. We sampled Chinese mitten crabs from six origins representing diverse aquatic environments and farming practices, and analyzed their δ¹³C, δ¹⁵N, δ²H, and δ¹⁸O stable isotope compositions in different sexes and tissues (hepatopancreas, muscle, and gonad). By comparing the classification performance of Random Forest, XGBoost, and Logistic Regression models, we found that the Random Forest model outperformed the others, achieving high accuracy (91.3%) in distinguishing samples from different origins. Interpretation of the optimal Random Forest model, using SHAP (SHapley Additive exPlanations) analysis, identified δ²H in male muscle, δ¹⁵N in female hepatopancreas, and δ¹³C in female hepatopancreas as the most influential features for discriminating geographic origin. This analysis highlighted the crucial role of environmental factors, such as water source, diet, and trophic level, in origin discrimination and demonstrated that isotopic characteristics of different tissues provide unique discriminatory information. This study offers a novel paradigm for stable isotope traceability based on explainable machine learning, significantly enhancing the identification capability and reliability of Chinese mitten crab origin traceability, and holds significant implications for food safety assurance. Full article

In a previous study, we found that mitochondrial DNA methylation occurred in the muscle tissue of Exopalaemon carinicauda under starvation stress. To explore whether this phenomenon also existed in other tissues, we used the bisulfite method (BSP) to detect the methylation of the mitochondrial genome in the intestinal tissues, hepatopancreas, gills, eye stalks, muscles, heart, and other tissues before and after starvation. In situ hybridization and qPCR techniques were used to analyze the expression of DNMT1 and DNMT3b involved in methylation regulation in different tissues. The results showed that the methylation rate was highest in intestinal tissue, followed by hepatopancreas, gills, heart, muscle, and eye stalk. Significantly different expression levels of DNMT1 and DNMT3b were found in the intestine and hepatopancreas with a higher expression pre-starvation and a lower expression post starvation. The expression levels of DNMT1 and DNMT3b in heart and muscle increased after starvation. The expression levels of DNMT1 and DNMT3b in the eye stalk were low and decreased significantly after starvation. The in situ hybridization of DNMT1 and DNMT3b further verified the results: the mRNA signal in intestinal and hepatopancreatic tissues of the starvation group was significantly weaker than that of the control group. No significant difference in mRNA signal intensity was found in the gill, muscle, and heart tissues of the starvation group compared with the control group. The mRNA signal in the eye stalk tissue of the starvation group was weaker than that of the control group. This study is the first to confirm different levels of mtDNA methylation in different tissues of E. carinicauda, which may be closely related to their biological functions. Full article

The cultured habitat of Eriocheir sinensis is a crucial factor influencing its nutritional quality. Therefore, it is essential to clarify the differences in the nutritional quality of Eriocheir sinensis reared in different habitats. This study investigated and compared the nutritional value of three edible parts (the hepatopancreas, gonads, and muscles) of female Eriocheir sinensis from three different habitats in the lower reach of the Yangtze River, with a special emphasis on lipid compounds. In addition to tissue indices, proximate composition, energy content, lipid classes, and fatty acid profile, eight lipid quality indices were proposed to evaluate the lipid nutritional quality. The results indicated that the Eriocheir sinensis from the three different habitats were all in good developmental condition. No significant differences were observed for the hepatopancreas index (HIS), gonadosomatic index (GSI), and total edible yield (TEY) among the three habitats, except for muscle index (MI), which was significantly higher in the L-crabs and E-crabs compared to the P-crabs. The highest protein content was found in the gonads, while the hepatopancreas had the highest crude lipid content. Regarding lipid classes, triglycerides dominated the hepatopancreas, and phospholipids were predominant in muscles, whereas phospholipids and triglycerides were predominant in approximately equal amounts in the gonads. Taking eight lipid quality indices into account together, the three major edible tissues of Eriocheir sinensis from the estuarine habitat had the highest nutritional value, followed by the hepatopancreas from the pond habitat. The current research will provide basic nutritional data for consumers to purchase Eriocheir sinensis and establish the theoretical groundwork for paving new paths for improving the nutritional quality combined with habitat conditions in future studies. Full article

Contaminants such as nano-polystyrenes (NPs) and heavy metal cocktail (HMC) have been found to disrupt physiological functions in aquatic organisms. Although HMC and NPs alone induce oxidative stress, their combined effects are not well understood. This study aimed to assess the combined effects of HMC and NPs on the freshwater shrimp (Macrobrachium rosenbergii). Shrimp were divided into seven groups, including the control group, and the experimental groups co-exposed to 0, 50, 100, 150, 200, and 250 µg/L NPs combined with 0.5 mg/L HMC. After 14 days, shrimp were sampled, and their hepatopancreas and muscle tissues were analyzed for oxidative biomarkers, biochemical parameters, and metabolic profiles. Moreover, the bioaccumulation rate of heavy metals was measured. Results showed that co-exposure to NPs and HMC increased superoxide dismutase, glutathione peroxidase, glutathione reductase activities, and malondialdehyde levels, while reducing glutathione and total antioxidant capacity. The integrated biomarker response indicated that co-exposure to HMC and NPs induces oxidative stress. A significant decrease was observed in aspartate aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase activities, glycogen, triglyceride, and total protein levels. However, lactate dehydrogenase activity was significantly increased. Co-exposure to HMC and NPs increased heavy metal bioaccumulation, induced oxidative stress, biochemical changes, and enhanced HMC toxicity in shrimp. Full article

Corazonin (Crz) is widely found in insects and crustaceans. In insects, Crz participates in the regulation of various physiological activities, including heartbeat, body color change, molting, and reproduction. However, the physiological effects of Crz in crustaceans remain largely unclear. In this study, the cDNAs encoding Crz and its putative receptor were isolated from the mud crab Scylla paramamosain. Tissue distribution analysis revealed that Sp-Crz was predominantly expressed in neural tissues, while its receptor (Sp-CrzR) was widely expressed in S. paramamosain, with a high expression level in the Y-organ. During ovarian development, Sp-Crz expression in the eyestalk ganglion was upregulated at the early and late vitellogenic stages, whereas its expression level in the cerebral ganglion displayed an initial downregulation at the early stage, followed by a remarkable upregulation at the late vitellogenic stage. The expression level of Sp-CrzR mRNA in the ovary increased significantly at the late vitellogenic stage. However, an opposite expression pattern was observed in the hepatopancreas and Y-organ. The immunohistochemistry result showed that Sp-Crz was distributed in the cells of the lamina ganglionaris, the medulla interna, and the X-organ of the eyestalk ganglion. It was revealed that the level of Sp-Vg in the hepatopancreas was not affected by the addition of Sp-Crz in vitro. However, the expression of Sp-VgR in ovarian explants was significantly induced by 6 h treatment with Sp-Crz at a concentration of 1 nM. In addition, the level of Sp-VgR in the ovary was significantly upregulated by 12 h injection of Sp-Crz. After long-term administration of Sp-Crz, the expression of Sp-VgR in the ovary, the E₂ content in hemolymph, the oocyte diameter, and the gonadosomatic index of S. paramamosain were significantly increased. In summary, these findings collectively indicate that the Sp-Crz signaling system participates in regulating the ovarian development of the mud crab. This study provides a new insight into the biological function of Crz during the ovarian development of the mud crab, which is of great significance for the sustainable development and utilization of mud crab resources. Full article

The progressive commercial deployment of multi-walled carbon nanotubes (MWCNTs) raises concerns about their terrestrial ecotoxicity. We exposed adult Cornu aspersum (150 snails; five replicates of three animals per time-point) to 50 mg L⁻¹ MWCNT-dosed Lactuca sativa for 30 days and quantified five mechanistic biomarkers alongside survival. Hemocyte spread-cell area increased by 48% (from 243 ± 22 µm² at day 0 to 360 ± 18 µm² at day 14, p < 0.001). Lysosomal membrane stability (neutral red retention) fell twofold within 72 h and to 10 min by day 30 (controls ≈ 60 min), indicating early, persistent destabilization. Micronucleus frequency rose above the ecogenotoxic threshold of 5‰ after 7 days, peaking at 8.3 ± 0.7‰ on day 14 (p < 0.01). Hepatopancreas metallothionein concentrations doubled by day 3 (2.1 ± 0.3 vs. 1.0 ± 0.2 µg g⁻¹ ww in controls) and remained >150% of control throughout exposure, consistent with metal impurity mobilization. Acetylcholinesterase activity in cephalic tissue declined by 50% after 7 days and by 73% after 30 days, revealing sustained neurotoxicity. Despite these pronounced sub-individual disturbances, cumulative mortality reached only 19% at day 30, suggesting substantial, but finite, physiological compensation. Collectively, the data demonstrate that a 50 mg L⁻¹ dietary load of MWCNTs elicits rapid cytotoxic, genotoxic, and neurotoxic responses in C. aspersum that precede overt lethality, underscoring the utility of this gastropod and the chosen biomarker suite for monitoring nanotube contamination in agro-ecosystems and food-grade snail farming. Full article

To investigate thermal tolerance, physiological responses, and molecular mechanisms of the narrow-clawed crayfish (Pontastacus leptodactylus) under acute thermal stress, the P. leptodactylus were acutely exposed to 4 different temperature groups—15 °C (control), 20 °C (T20), 25 °C (T25), and 30 °C (T30)—across 6 time points (3 h, 6 h, 12 h, 24 h, 48 h, and 72 h). Survival rates were recorded at each interval. Subsequent analyses comprised: (1) Hemolymph biochemical parameter determination; (2) hepatopancreatic antioxidant capacity assessment; (3) hepatopancreatic histopathology; and (4) comparative transcriptomics analysis of the hepatopancreas. The results showed that the survival rate in the T30 group significantly declined after 48 h of stress. The histological analysis of the hepatopancreas revealed tissue damage in both the T25 and T30 groups. The T25 group exhibited a notable increase in B-cell density and severe vacuolization, while the T30 group displayed disorganized hepatopancreatic cell arrangement, marked necrosis, and structural phenotypes in hepatopancreatic tubules, including lumen expansion and the loss of the star-shaped lumen structure. Biochemical analyses indicated pronounced declines in energy metabolism markers under elevated temperatures. Furthermore, the T30 group exhibited elevated levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT), alongside diminished total antioxidant capacity (T-AOC). Similarly, the T25 group displayed increased MDA and CAT levels but decreased T-AOC. Comparative transcriptomic analysis demonstrated that differentially expressed genes (DEGs) in the control vs. T25 group were predominantly enriched in metabolic pathways, whereas DEGs identified in control vs. T30 and T25 vs. T30 comparisons showed significant enrichment in energy metabolism and apoptotic processes. Based on these findings, we concluded that acute thermal stress induces mortality in P. leptodactylus through hepatopancreatic structural damage, energy metabolism dysregulation, and excessive ROS accumulation. Notably, P. leptodactylus should be excluded from aquaculture environments exceeding 25 °C. These results enhance understanding of the adaptive mechanisms of P. leptodactylus under acute thermal stress and provide actionable insights to advance its industrial cultivation. Full article

In this study, we identified two β-hexosaminidase A isoforms (Mn-HexA1 and Mn-HexA2) in Macrobrachium nipponense through bioinformatics analysis and characterized their phylogenetic relationships. The open reading frames of Mn-HexA1 and Mn-HexA2 were 1641 bp (encoding 546 amino acids) and 1473 bp (encoding 490 amino acids), respectively. Both isoforms exhibited high conservation, sharing five identical functional domains, with 58.43% amino acid sequence similarity. Quantitative PCR analysis revealed that Mn-HexA1 expression was significantly higher than Mn-HexA2 across all developmental stages and tissues. During embryonic development, Mn-HexA1 showed elevated expression at the ZS, L15, and PL10, while Mn-HexA2 was upregulated only at L15 and PL10. In the breeding season and non-breeding season, Mn-HexA1 and Mn-HexA2 were predominantly expressed in the hepatopancreas at levels significantly higher than in other tissues. Moreover, their expression in most tissues was higher during the breeding season than in the non-breeding season. RNA interference experiments revealed that knockdown of both Mn-HexA isoforms significantly accelerated ovarian development in M. nipponense, with the Mn-HexA1-silenced group exhibiting faster progression than the Mn-HexA2-silenced group. These results demonstrate that Mn-HexA genes function as negative regulators of ovarian maturation, with Mn-HexA1 exerting a stronger inhibitory effect than Mn-HexA2. Full article

Penaeus vannamei hemocyanin (PvHMC) exhibits multifunctional roles in immunity, often mediated by various post-translational modifications. While linear ubiquitination catalyzed by LUBAC in mammals regulates immune signaling, its role in crustacean immunity remains unclear. Here, we investigated the regulatory mechanism of PvHMC linear ubiquitination mediated by an E3 ligase PvLUBEL (a HOIP homolog), with emphasis on its role in shrimp immunity defending against diverse pathogens. We detected linear ubiquitination of PvHMC in multiple tissues, including hemocytes and the hepatopancreas. During Vibrio parahaemolyticus infection, the expression of PvLUBEL and the level of PvHMC linear ubiquitination were suppressed, whereas infection by white spot syndrome virus (WSSV) led to their upregulation. Structural analyses revealed that PvLUBEL, which shares a conserved RING-IBR-RING (RBR) domain with mammalian HOIP, serves as the catalytic subunit. Notably, inhibition of PvLUBEL via HOIPIN-1 (a covalent inhibitor) or RNA interference (RNAi) significantly reduced PvHMC linear ubiquitination, thereby increasing pathogen proliferation and decreasing host survival. These findings unveil a novel post-translational regulatory mechanism in which PvLUBEL-mediated linear ubiquitination of PvHMC underpins the shrimp immune response against aquaculture pathogens. Full article

The pigmentation and coloration of P. vannamei are primarily determined by the type and concentration of dietary carotenoids, with carotenoid-rich macroalgae serving as effective dietary supplements to enhance pigment accumulation and improve commercial quality. Five experimental diets were formulated with 3% brown algae (Saccharina japonica, SJ group; Sargassum fusiforme, SF group), red algae (Neoporphyra haitanensis, NH group), or 0.1% purified carotenoids (zeaxanthin, ZT group; fucoxanthin, FX group). The results showed that both macroalgae and carotenoid supplementation significantly enhanced weight gain rate (WGR) and specific growth rate (SGR) compared to the control group, with the zeaxanthin and fucoxanthin groups exhibiting the greatest improvements (1.6-fold and 1.3-fold, respectively). The N. haitanensis-supplemented diet, which had the highest carotenoid content, resulted in the most pronounced carotenoid accumulation (2.58-fold increase). Carotenoids were mainly deposited in the exoskeleton, followed by the hepatopancreas, with minimal accumulation in muscle tissue. α-Carotene and β-carotene contributed most to exoskeleton deposition, while lutein and zeaxanthin had weaker effects, and fucoxanthin showed no significant influence. Tissue-specific distribution patterns were observed: α-carotene and β-carotene were localized in the exoskeleton; fucoxanthin and zeaxanthin were found only in the exoskeleton and hepatopancreas, and astaxanthin was present in all three tissues. Furthermore, astaxanthin diesters (C20:5 and C22:6) were primarily detected in the exoskeleton and hepatopancreas, while monoesters (C16:0 and C18:0) were specific to muscle. These findings suggest that targeted supplementation of algal-derived carotenoids can enhance both growth and pigmentation in P. vannamei, providing a theoretical basis for the development of functional feeds to improve shrimp commercial quality. Full article

The hepatopancreas of Procambarus clarkii plays a crucial role in metabolism and immune response, encompassing vital physiological functions. In our study, we established a hepatopancreatic injury model using thioacetamide (TAA) and evaluated the therapeutic potential of a commercial astaxanthin-based product (AST-product) on hepatopancreatic health. The experimental framework included a control group (Con), an injury model group (M), and a treatment group (T), enabling a comprehensive analysis of the effects of treatments on hepatopancreatic biochemical markers, tissue architecture, gene expression, and metabolic pathways. The biochemical results indicated significant oxidative damage and fibrosis in the M group post-TAA treatment, evidenced by increased malondialdehyde (MDA) levels, decreased superoxide dismutase (SOD) activity, and the disruption of tubular structures. Conversely, treatment with the AST-product significantly reduced MDA levels and ameliorated oxidative stress. Histological evaluations using hematoxylin and eosin (HE) and Sirius Red staining confirmed that the AST-product preserved tubular integrity and inhibited fibrosis progression. Metabolomic profiling revealed that the AST-product modulated key metabolic pathways, including arginine and proline metabolism, porphyrin metabolism, and nucleotide metabolism, which are critical for maintaining energy supply and antioxidative capabilities. This modulation mitigated the TAA-induced oxidative damage. Moreover, qPCR analysis demonstrated that the AST-product downregulated the pro-apoptotic gene CASP2, upregulated the energy metabolism-related gene NDUFA7, and enhanced the expression of the immune-related gene lysozyme, thereby boosting pathogen resistance. These findings elucidate the robust protective effects of the AST-product on hepatopancreatic health in P. clarkii, highlighting its potential to reduce oxidative stress, inhibit fibrosis, and enhance immune responses. This study provides a novel strategy for improving P. clarkii health in aquaculture and contributes valuable insights into hepatopancreatic protection and disease prevention in shrimp farming. Full article

Nanoplastics (NPs) pose a significant environmental threat due to their small sizes, widespread distribution, and bioavailability, enabling interactions with marine organisms from pelagic to benthic species. In this study, the effects of 10 days of exposure to waterborne poly(methyl)methacrylate (PMMA) NPs were evaluated in the crab Carcinus maenas by assessing behavioral and biochemical endpoints (in gills, hepatopancreas, muscle, and hemolymph). Behavioral assessments using an open field test revealed that exposure to PMMA NPs resulted in an increase in distance walked (from 73.662 ± 17.137 cm in control to 248.560 ± 25.462 cm in the highest PMMA NPs concentration) and in random movement patterns. Muscle acetylcholinesterase (AChE) activity decreased from 10.83 ± 0.73 to 6.75 ± 0.45 nmol/min/mg of protein with PMMA NPs concentration increase, which, combined with behavioral responses, suggests neurological incapacities. In the gills and hepatopancreas, defense and detoxification mechanisms were activated, with a significant increase in superoxide dismutase (SOD) activity (at 20 µg/L in gills and 80 µg/L in hepatopancreas) and glutathione S-transferases (GSTs) activity (all PMMA NPs concentrations in gills and 20 and 320 µg/L in hepatopancreas). Despite these activations, oxidative damage was observed, with a significant increase in protein carbonylation (PC) levels (20, 80, and 320 µg/L in gills and 5, 20, and 80 µg/L in hepatopancreas) and lipid peroxidation (LPO) (80 and 320 µg/L in gills and 80 µg/L in hepatopancreas). Effects on hemolymph followed a pattern similar to those reported for gills and hepatopancreas. An increase in SOD hemolymph activity was observed in organisms exposed to 5 and 80 µg/L, and GSTs activity increased in crabs exposed to 80 µg/L. Oxidative damage in hemolymph was only detected through LPO at 5 and 320 µg/L. Overall, this study showed that PMMA NPs induce biochemical alterations and damage in different tissues of C. maenas and affect its behavior with potential impacts at a population level. Full article

Salinity is a key environmental factor influencing the survival of aquatic organisms, and transcriptional plasticity is a crucial emergency response to environmental changes. However, most transcriptomic studies on salinity responses have not explored the expression patterns and regulatory mechanisms across different tissues. The Suminoe oyster (Crassostrea ariakensis), a sessile estuarine species that inhabits fluctuating salinity environments, provides an excellent model for studying the molecular basis of salinity response divergence. All eight tissues responded to acute salinity stresses and exhibited distinct tissue-specific expression patterns in both mRNA and long non-coding RNA (lncRNA) profiles across three salinity conditions. The hepatopancreas and striated muscle were identified as tissues specifically sensitive to hyper- and hypo-saline stress, respectively, based on the number, expression pattern, and plasticity of differentially expressed genes (DEGs). We established lncRNA-mRNA regulatory relationships that environmentally responsive lncRNAs enhanced DEGs’ expression and underpinning tissue-specific responses. Under moderate stress, the hepatopancreas and striated muscle initiated positive responses related to water transport and shell closure, respectively. Under severe stress, the hepatopancreas activated cellular resistance pathways, while the striated muscle experienced significant cell death. Our findings provide insights into lncRNA-mediated, tissue-specific environmental responses and lay the foundation for further research into the adaptive evolution of tissue-specific regulation. Full article