Eriocheir Sinensis Research Articles

Exposure to copper and copper-based nanoparticles induces hepatopancreatic mitochondrial dysfunction by triggering mtROS mediated apoptosis and mitophagy in Eriocheir sinensis.

Copper (Cu) is an important metal pollutant commonly found in aquatic environment owing to its inherent bioaccumulation and biomagnification potentials and long-term persistence in environmental compartments. The application of novel fabricated copper nanoparticles (Cu-NPs) has led to cytotoxicity in aquatic animals. However, the differences in underlying toxicity mechanisms between Cu-NPs and waterborne Cu (such as CuSO4) remain unelucidated. Herein, the mechanisms underlying the CuSO4/Cu-NPs-mediated perturbation of the hepatopancreatic mitochondrial function at different concentrations were investigated and compared. After exposing Eriocheir sinensis to 0 (control), 5, 50, and 500 μg/L CuSO4 and 10 μg/L Cu-NPs for 21 days, hepatopancreases were retrieved. The results revealed that Cu-NPs or CuSO4 (50 and 500 μg/L) induced ultrastructural damage following a time-dose effect, as indicated by swelling and degeneration of the lumen of hepatic tubules. Excess CuSO4 or Cu-NPs exposure decreased the antioxidative capacity and led to the over-accumulation of mitochondrial ROS. Moreover, the mitochondrial membrane potential (ΔΨm) was reduced and apoptosis induced. Additionally, both CuSO4 and Cu-NPs increased the numbers of mitophagosomes and the mRNA and protein levels of LC3B, and triggered mitophagy through PRKN-independent pathway; however, mostly the BNIP3L/Beclin1 pathway was involved in excess CuSO4-induced mitophagy. Altogether, this study provides a basis for exploring Cu-mediated potential mitochondrial autophagy activation mechanisms and their effects on environmental toxicity.

Nanopore-Based Sequencing of the Full-Length Transcriptome of Male and Female Cleavage-Stage Embryos of the Chinese Mitten Crab (Eriocheir sinensis)

The cleavage stage plays a crucial role in embryo development, characterized by a swift surge in cell proliferation alongside the accurate genetic material transmission to offspring. To delve into the characteristics of sex development during the cleavage stage of embryos, we generated the full-length transcriptome of Eriocheir sinensis male and female cleavage-stage embryos using Oxford Nanopore Technologies (ONT). Notably, this investigation represents the first sequencing effort distinguishing between genders in E. sinensis embryos. In the transcriptome structure analysis, male and female cleavage-stage embryos, while not clustered, exhibited a comparable frequency of alternative splicing (AS) occurrences. We also successfully identified 2875 transcription factors (TFs). The quantitative analysis showed the top 150 genes, in which the highly expressed genes in male embryos predominantly related to protein synthesis and metabolism. Further investigation unveiled 500 differentially expressed genes (DEGs), of which 7 male-biased ribosomal protein genes (RPGs) were particularly noteworthy and further confirmed. These analyses suggest that there may be a more active protein synthesis process in male E. sinensis cleavage-stage embryos. Furthermore, among the 2875 identified TFs, we predicted that 18 TFs could regulate the differentially expressed RPGs, with most TFs belonging to the zf-C2H2 and Homeobox families, which are crucial for embryonic development. During the cleavage stage of E. sinensis, the differential RPGs between genders were intricately linked to energy metabolism. We proposed that these RPGs exert regulatory effects on gene expression in E. sinensis, thereby regulating the difference of development between male and females. Our research sheds light on the developmental mechanisms of E. sinensis during the embryo stage and establishes a groundwork for a deeper understanding of sex development in E. sinensis. The results also provide comprehensive full-length transcriptome data for future gene expression and genetic studies in E. sinensis.

Development of Microsatellite Markers from Transcriptome of Eriocheir sinensis and Their Application in Multiplex PCR Panels

Background: The development of genetic markers is crucial for aquaculture and population genetics. Polyallelic microsatellite markers are widely used for breeding and family management of Eriocheir sinensis (E. sinensis), contributing to the sustainable development of the industry. Methods: Through transcriptome analysis, 100 highly polymorphic SSR markers were identified and developed. From these, four multiplex PCR panels, each containing 16 markers, were constructed and applied to parentage assignment in six E. sinensis families. Results: The number of alleles (Na) ranged from 7 to 21, the observed heterozygosity (Ho) varied from 0.356 to 0.951, and the expected heterozygosity (He) varied from 0.656 to 0.909. The polymorphism information content (PIC) ranged from 0.633 to 0.900. The CERVUS analysis showed that using only the two most informative multiplex PCR panels, assignment success rates exceeded 90.34%, with 100% accuracy in assigning offspring to parents when three or four panels were used. Conclusions: This method significantly enhances the efficiency of microsatellite marker analysis, which provides a convenient and cost-effective method for breeding programs and family management of E. sinensis.

Dietary yeast culture can protect against chronic heat stress by improving the survival, antioxidant capacity, immune response, and gut health of juvenile Chinese mitten crab (Eriocheir sinensis)

Dietary yeast culture can protect against chronic heat stress by improving the survival, antioxidant capacity, immune response, and gut health of juvenile Chinese mitten crab (Eriocheir sinensis)

Analysis of molecular advantages in offspring of large-sized Chinese mitten crabs based on reproductive lineage

Analysis of molecular advantages in offspring of large-sized Chinese mitten crabs based on reproductive lineage

Key non-volatile taste components and characteristics in abdominal muscle of Eriocheir sinensis under various thermal processing methods

This study identified the key non-volatile taste components and characteristics in the abdominal muscle (AM) of Eriocheir sinensis under various thermal processing methods: boiling at rising temperature (BO-R), boiling at constant temperature (BO-C), steaming with water vapor (ST) and salt-baked (BK). The results showed that arginine (Arg), alanine (Ala), glycine (Gly), glutamate (Glu), 5’-AMP, histidine (His), lysine (Lys), proline (Pro), K+, PO43−, betaine, succinic acid, and lactic acid were the key taste contributors, exhibiting taste activity values (TAV) higher than 1.0. Compared to BO groups, ST and BK group showed higher expression in SFAAs. BK exhibited the highest Arg, 5’-AMP contents, EUC (4.49 g MSG/100 g), and reduced BFAAs. The cluster and correlation analysis demonstrated that Arg, Ala, and His were identified as the primary differential components under various thermal degradation. These findings could deepen the understanding of taste for subsequent studies.

CBS/CSE mediated H2S production induced AMPs expression through Toll pathway in crabs with black gill syndrome

The occurrence of black gill syndrome (BGS) is a serious threat to the healthy culture of Eriocheir sinensis. Studying the innate immune ability of E. sinensis with BGS can help develop new strategies for disease prevention and treatment. Antimicrobial peptides (AMPs) have crucial roles in crustacean humoral immunity. In this study, we found that the expression levels of two antilipopolysaccharide factor (EsALF7 and EsALF-L), one Toll receptor 3 (EsToll3), and one Pelle kinase (EsPelle) were upregulated in E. sinensis with BGS. Moreover, ALFs expressions in E. sinensis with BGS were positively regulated by EsToll3 and EsPelle. The content of hydrogen sulfide (H2S) in the gills of E. sinensis with BGS was increased. Further studies showed that the expressions of cystathionine β-synthase (EsCBS) and cystathionine γ-lyase (EsCSE) in the gills of E. sinensis with BGS were upregulated, which positively regulate the production of H2S. Whether there was a correlation between the upregulation of ALFs expression and changes in H2S content? Further studies showed that 1) the expressions of EsToll3, EsPelle, EsALF7, and EsALF-L in the gills of E. sinensis were upregulated under H2S exposure and 2) the knockdown of EsCBS and EsCSE in E. sinensis reduced the transcriptions of EsToll3, EsPelle, EsALF7, and EsALF-L. To sum up, these findings suggest that upregulation of H2S content induced by CBS/CSE promotes the expression of ALFs through the Toll pathway in E. sinensis suffering from BGS.

Comparative study on growth performance and nutritional quality of Eriocheir sinensis between Liaohe River strain and Yangtze River strain under rice field culture environment

This study investigated the similarities and differences in catch rates, growth performance, proximate composition, amino acid content, and fatty acid profiles between the Yangtze River crab and the Liaohe River crab in rice aquaculture systems in northern China. A three-month culture experiment was conducted for the Yangtze River crab and the Liaohe River crab in a rice located at longitude 124.82° and latitude 43.50°. The results revealed that Liaohe River crab had higher catch rate and faster growth rates than Yangtze River crab, and the female crab had earlier ovaries. The edible tissues of Liaohe River crabs contain higher crude protein and fat contents, featuring a more reasonable amino acid composition and structure. Meanwhile, the gonads of male and female Yangtze River crabs had higher PUFA content. In conclusion, under the conditions of this experiment, the Liaohe River crab demonstrated a significant growth advantage.

Notch signaling regulates limb regeneration through Hes1 and HeyL in the Chinese mitten crab

Tissue regeneration is an efficient strategy developed by animals to compensate for damaged tissues, involving various types of progenitor cells. Deciphering the signal network that modulates the activity of these progenitors during regeneration is crucial for understanding the differences in regenerative capacities across species. In this study, we evaluated the expression profile and phenotypic function of Notch signaling during limb regeneration in arthropod Chinese mitten crabs. The expression of key components of the Notch signaling pathway was upregulated at 7-day post-autotomy (7 DPA), and declined later at 18-day post-autotomy (18 DPA). To assess the role of Notch, we injected dsRNA targeting the Notch gene into the automized area and evaluated the regeneration efficiency. Our results indicated that blocking Notch signaling led to regenerative defects, manifested by delays in the wound closure and blastema emergence processes. Furthermore, the expression of Notch target genes, Hes1 and HeyL, was significantly reduced following Notch knockdown by dsRNA. Knockdown of Hes1 specifically impaired the proliferation and expression of neural progenitor cell markers, without affecting myogenic cells. In contrast, blockage of HeyL inhibited the proliferation and expression of markers in both activated neurogenic and myogenic progenitor cells, while up-regulating markers of quiescent neural progenitor cells. These findings suggest that Notch signaling plays an important role in limb regeneration of E. sinensis by activating downstream effectors Hes1 and HeyL, regulating neurogenesis and myogenesis through distinct mechanisms.

Integration of metabolomics and transcriptomics reveals the toxicological mechanism of deltamethrin exposure in Chinese mitten crab Eriocheir sinensis

This study investigated the toxicological mechanism of deltamethrin on Chinese mitten crab Eriocheir sinensis juveniles in fresh water. We first conducted an acute toxicity test, followed by laboratory methods to detect changes in immune-related indices in terms of antioxidant enzyme markers, lipid metabolism-related genes, and autophagy-related and apoptosis genes. The acute toxicity (96-h LC50) of deltamethrin to E. sinensis was 7.195 μg/L. After 48 h of exposure, serum showed elevated immune-related indices (P < 0.05) for alkaline phosphatase (AKP), acid phosphatase (ACP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), complement components C3 and C4, and the key pro-inflammatory cytokines interleukin-6, interleukin-1β, and tumor necrosis factor alpha (TNF-α). In hepatopancreas at 48 h, indicators related to the antioxidant system, namely superoxide dismutase (SOD) and glutathione (GSH), were significantly elevated, whereas nitric oxide and total antioxidant capacity (T-AOC) were decreased (P < 0.05). In contrast, lipid metabolism indices for triglyceride (TG), total cholesterol (TC), and malondialdehyde (MDA) were increased (P < 0.05). Transcriptomics and metabolomics revealed that exposure to deltamethrin disrupted the lipid metabolic process in the hepatopancreas mainly by altering fatty acid synthesis, amino acid metabolism, immune signaling, and autophagy activation, while the exposure increased the content of phospholipids and cholesterol but decreased the levels of amino acids and palmitoleic acid. Quantitative genetics revealed significantly aberrantly expressed (P < 0.05) lipid metabolism-related genes, including acc1, fasn, scd1, and pnpla2, all key genes involved in lipid accumulation. Deltamethrin exposure also significantly altered (P < 0.05) gene expression levels for Toll-like receptor (tlr), myeloid differentiation factor 88 (myd88), crustin1, anti-lipopolysaccharide factor isoform 3 (alf3), tumor necrosis factor alpha (tnf-α), and NF-κB transcription factor relish. Furthermore, deltamethrin activated the toll-like receptor/major myeloid differentiation response gene 88/nuclear factor kappa-light-chain-enhancer of activated B cells (TLR/MyD88/NF-kB) signaling pathway, which activates a nonspecific immune response in E. sinensis. Additionally, carnitine palmitoyltransferase 1 A (cpt1a), cytochrome c (cyt-c), adenosine 5′-monophosphate (amp)-activated protein kinase (ampk), the autophagosomal protein microtubule-associated protein 1 light chain 3c (lc3c), and the autophagy-related proteins beclin1, atg5, atg12 were significantly induced (P < 0.05) in the adenosine monophosphate-activated protein kinase/rapamycin (AMPK/mTOR) signaling pathway. These changes resulted in excess free radicals, causing oxidative stress in the mitochondrial membrane, promoting mitochondrial autophagy. The results confirm that deltamethrin exposure can induce hepatopancreatic injury by promoting mitochondrial autophagy, activating an immune response, and inhibiting lipid metabolism. Overall, this study provides multi-level information to reveal the toxic effects of deltamethrin on E. sinensis.

Deciphering the impact of MreB on the morphology and pathogenicity of the aquatic pathogen Spiroplasma eriocheiris

BackgroundSpiroplasma eriocheiris has been proved to be a pathogen causing tremor disease of Eriocheir sinensis, it is also infectious to other aquatic crustaceans, resulting in a serious threat on the sustainable development of the aquaculture industry. S. eriocheiris is a helical-shaped microbe without a cell wall, and its motility is related to the cytoskeleton protein MreB which belongs to the actin superfamily and has five MreB homologs.ResultsIn this study, we purified MreB3, MreB4 and MreB5, and successfully prepared monoclonal antibodies. After S. eriocheiris treated with actin stabilizator Phalloidin and inhibitors A22, we found that Phalloidin and A22 affect the S. eriocheiris morphology by altering MreB expression. We confirmed that the ability of S. eriocheiris to invade E. sinensis was increased after treatment with Phalloidin, including that the morphology of E. sinensis blood lymphocytes was deteriorated, blood lymphocytes viability was decreased, peroxidase activity and cell necrosis were increased. On the contrary, the pathogenicity of S. eriocheiris decreased after treatment with A22.ConclusionsOur findings suggest that the MreB protein in S. eriocheiris plays a crucial role in its morphology and pathogenicity, providing new insights into potential strategies for the prevention and control of S. eriocheiris infections.

Health risks and sources of PCDD/Fs and PCBs residue in cultured crabs

The Chinese mitten crab (Eriocheir sinensis) holds significant importance as a popular aquaculture food source; however, there are concerns about its potential contamination with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) from both food and aquatic environment. To assess the associated health risks and identify potential sources of contamination in crabs, a comprehensive investigation was conducted, including a total of 70 samples from the crab food web. The results demonstrated that crabs predominantly exhibited elevated concentrations of PCBs and dl-PCBs, with mean concentrations of 12 207 ± 11 962 pg g-1 and 554 ± 203 pg g-1, respectively, while PCDD/Fs concentrations were comparatively lower at 20 ± 17 pg g-1. The accumulation of PCBs in crabs significantly surpassed that of PCDD/Fs. The material balance of PCDD/Fs and PCBs in the crab food web was estimated, indicating that sediments and feeds likely constitute the two primary sources of PCDD/Fs and PCBs in crabs. The monthly intake of PCDD/Fs and PCBs through crab consumption accounted for 30% of the dietary intake, which was well below the provisional tolerable monthly intake (PTMI) limit. The weekly intake of PCDD/Fs and PCBs for adults consuming one crab (100 g) does not pose health risks and the recommended weekly intake of white crabmeat and brown crabmeat is 443 g and 21 g, respectively.

Breaking it down: leaf litter processing by invasive Chinese mitten crabs and associated effects on water quality in laboratory conditions

Breaking it down: leaf litter processing by invasive Chinese mitten crabs and associated effects on water quality in laboratory conditions

External nutrients fattening promotes hepatopancreases development, metabolism, nutrient deposition and flavor yield during the maturation stage in female Chinese mitten crab (Eriocheir sinensis)

The nutritive value and maturity status of hepatopancreases dominates the quality of Chinese mitten crab, Eriocheir sinensis. However, the underlying function and regulatory mechanism, as well as the external nutrient factors on the development of hepatopancreases in different growth stages of E. sinensis remains unclear. In this study, we first revealed the function of hepatopancreases feeding with iced trash fish (ITF) during the whole culture period; and further investigated the underlying mechanism on nutrient deposition and flavor yield feeding with formulated feed (FEED) in replacement of ITF in female E. sinensis. From the results, growth performance and metabolism indicate E. sinensis was robustly developed, and ITF promotes growth and hepatopancreases development during the maturation period. Meanwhile, activation of fatty acid and amino acid metabolism in hepatopancreases resulted in depletion of monounsaturated fatty acids (MUFAs) but promoted protein deposition during the maturation stage. Integrated analysis of transcriptome and metabolome reveal metabolism, biosynthesis, and flavor presentation were intensively active during maturation, evidenced by the expression of key genes of ALDH, TBXAs, HADHA, UPB1, CYP2, GST, and γ-GT-X1; as well as the key metabolites of GMP and IMP. Additionally, substitution of ITF with FEED further confirm full price artificial feed could meet the nutrient requirements during the maturation period, evidenced by the growth performance, fatty acid and amino acid derived nutrient and flavor yield in hepatopancreases. In conclusion, nutrient and flavor deposition was associated with the fast development of hepatopancreases, and fatten with full price compound feed contributes to the nutrient requirement and flavor yield during the maturation stage.

Nanopolystyrene and phoxim pollution: A threat to hepatopancreas toxicity in Chinese mitten crab (Eriocheir sinensis)

Significant concerns have been raised by the widespread pollutants phoxim (PHO) and nanopolystyrene (NP) in the natural environment. This study evaluated the toxicity effects on the hepatopancreas of Eriocheir sinensis caused by NP and/or PHO at concentrations found in the environment. Subchronic exposure to NP and/or PHO triggered hepatopancreas histological damage within a 21-day exposure period. The NP, PHO, and co-exposure (NPO) groups exhibited fewer blister-like (B) cells, along with the appearance of vacuolation. Furthermore, these exposures induced impairment in the hepatic tubule mucus barrier and mechanical barrier, as evidenced by altered expression of oxidative stress-related genes, mucin-related genes, and TJ-related genes. Additionally, alterations in immunity-related genes and inflammatory cytokine genes expression were observed. The findings showed that hepatopancreas inflammation was caused by both individual and combined exposure to NP and PHO and that the inflammatory response was exacerbated by the co-exposure. The possible pathways of hepatopancreas toxicity were further investigated by transcriptomic analysis. Hepatopancreas inflammation was brought on by subchronic exposure to PHO and co-exposure; this inflammation was exacerbated by co-exposure and was backed by the activation of NF-κB signaling pathway via targeting-related genes. In summary, this research represents the initial documentation, to the best of our understanding of the detrimental effects of exposured to NP and/or PHO at levels found in the environment disrupt the hepatopancreas mucus and mechanical barrier in crustaceans, triggering inflammatory responses. These findings highlight the significance of NP and/or PHO pollution for hepatopancreas health.

Rapid Identification of the Geographical Origin of the Chinese Mitten Crab (Eriocheir sinensis) Using Near-Infrared Spectroscopy.

The Chinese mitten crab (Eriocheir sinensis) is highly valued by consumers for its delicious taste and high nutritional content, including proteins and trace elements, giving it significant economic value. However, variations in taste and nutritional value among crabs from different regions lead to considerable price differences, fueling the prevalence of counterfeit crabs in the market. Currently, there are no rapid detection methods to verify the origin of Chinese mitten crabs, making it crucial to develop fast and accurate detection techniques to protect consumer rights. This study focused on Chinese mitten crabs from different regions, specifically Hongze Lake, Tuo Lake, and Weishan Lake, by collecting near-infrared (NIR) diffuse reflectance spectral data from both the abdomen and carapace regions of the crabs. To eliminate noise from the spectral data, pretreatment was performed using Savitzky-Golay (SG) smoothing, Standard Normal Variate (SNV) transformation, and Multiplicative Scatter Correction (MSC). Key wavelengths reflecting the origin of Chinese mitten crabs were selected using Competitive Adaptive Reweighted Sampling (CARS), Bootstrap Soft Shrinkage (BOSS), and Uninformative Variable Elimination (UVE) algorithms. Finally, Support Vector Machine (SVM), Convolutional Neural Network (CNN), and Back Propagation Neural Network (BP) models were developed for rapid detection of crab origin. The results demonstrated that MSC provided the best preprocessing performance for NIR spectral data from both the abdomen and back of the crabs. For abdomen data, the SVM model developed using feature wavelengths selected by the CARS algorithm after MSC preprocessing achieved the highest accuracy (Acc) of 90.00%, with precision (P), recall (R), and F1-score for crabs from Weishan Lake at 89.29%, 86.21%, and 87.72%, respectively; for crabs from Tuo Lake at 86.96%, 95.24%, and 90.91%; and for crabs from Hongze Lake at 90.00%, 93.10%, and 91.53%. For carapace data, the SVM model based on wavelengths selected by the BOSS algorithm after MSC pretreatment achieved the best performance, with an Acc of 87.50%, and P, R, and F1 for crabs from Weishan Lake at 77.14%, 93.10%, and 84.38%; for Tuo Lake crabs at 100%, 90.47%, and 95.00%; and for Hongze Lake crabs at 92.31%, 80.00%, and 85.71%. In conclusion, NIR spectroscopy can effectively detect the origin of Chinese mitten crabs, providing technical support for developing rapid detection instruments and thereby safeguarding consumer rights.

Effects of microplastics separate exposure and co-exposure to 17β-estradiol on the productive performance of juvenile female Chinese mitten crab (Eriocheir sinensis)

Microplastics (MPs) and endocrine-disrupting chemicals are persistent and ubiquitous pollutants in aquatic environments. The coexistence of MPs and 17β-estradiol (E2) in aquaculture water is concerning, yet their combined impact on aquaculture products remains unclear. In this study, we investigated the individual and combined effects of MPs and E2 on juvenile female Chinese mitten crabs (Eriocheir sinensis). The results revealed that MPs and E2, alone and in combination, damage the histology and ultrastructure of the hepatopancreas, reduce lipid storage, and inhibit the expression of genes related to innate immunity, energy metabolism, and reproductive development in the hepatopancreas. These effects result in decreased innate immunity and impact growth and development. MPs and E2 also damage pereiopod muscles and ovarian tissues, impairing locomotor function and reproductive development. The coexposure group exhibited the combined damage effects of MPs and E2. Fluctuations in gene expression at different time points suggest that E. sinensis is self-regulated in response to external stimuli from MPs and E2. These findings emphasize the effects of MPs and E2, indicating that their coexistence in aquaculture environments threatens the productive performance of E. sinensis.

Comparison analysis of circulating hemocytes in decapod crustaceans

Hemocytes are the primary immune cells of crustaceans. Few comparison studies have been done among different crustaceans and some key parameters of circulating hemocytes have not been investigated. Here, we compared the circulating hemocytes in six decapod crustaceans, Cherax quadrinatus, Procambarus clarkii, Penaeus vannamei, Penaeus monodon, Eriocheir sinensis, and Scylla paramamosain. Although the hemocytes of different species vary in size, they share common morphological characteristics. Based on their morphological features, circulating hemocytes can be basically classified into granular cells (GCs), semi-granular cells (SGCs), and hyaline cells (HCs). In the six decapods analyzed in this study, the proportion of GCs varied from 10 % to 30 %. P. vannamei, P. monodon, and P. clarkii had fewer GCs in circulation than the other three species. Correspondingly, proliferation was detected only in a small portion of cells in P. vannamei, P. monodon, and P. clarkii under physical conditions. The hemocyte renewal rates for P. clarkii, E. sinensis, and C. quadrinatus were 6.1 %, 5.1 %, and 1.5 % per day, while no steady new hemocyte production was found in S. paramamosain within six days. These data give a general picture of the similarities and differences of circulating hemocytes in decapods and provide a base for an in-depth study of their immune system.

Stimulation of inactivated Metschnikowia bicuspidata promotes the growth, and immunity of Eriocheir sinensis larvae

The Chinese mitten crab (Eriocheir sinensis) is an economically essential crustacean specie in China. The outbreak of disease caused by Metschnikowia bicuspidata has resulted in high mortality and huge economic loss in the E. sinensis aquaculture industry. Immune priming can protect invertebrates against pathogens in the second exposure, which has been reported in adult E. sinensis and provides a novel approach for disease control. This study evaluated the effects of treatment with formalin-killed M. bicuspidata on the growth, development, and immunity of E. sinensis embryos and larvae. Stimulation of E. sinensis embryos with inactivated M. bicuspidata (Mb group) did not significantly affect the mass and size of embryos. While the carapace width, abdominal length, and tail length of larvae in the Mb group were significantly longer than those of control group in most stages. At 120 h and 144 h after embryo hatching, the metamorphosis rate of larvae in the Mb group was 24.59-fold (p < 0.05) and 16.07-fold (p < 0.001) higher than that in the control group. Moreover, after the larvae suffered alive M. bicuspidata challenge, the mortality in the Mb group significantly decreased (0.48-fold, p < 0.05) compared with that in the control group, and the mRNA expression levels of genes related to immunity (MAPK, Toll2, and STAT), growth (ATGL, Chi, Chymotrypsin, and mTOR), and development (Ubx) were significantly increased in the Mb group. These results suggested that stimulation of E. sinensis embryos with inactivated M. bicuspidata significantly promoted the growth and development of larvae and endowed them with stronger resistant capacity to M. bicuspidate. This finding may provide a novel and safe approach for preventing disease and improving larvae quality in E. sinensis aquaculture.

Water pollutant cadmium-induced intestinal inflammation in Eriocheir sinensis and potential therapeutic drugs

ObjectiveEriocheir sinensis is a significant crustacean in freshwater aquaculture. However, this industry is vulnerable to diseases, including intestinal inflammation. Cadmium (Cd) is a water pollutant that exacerbates intestinal inflammation in Eriocheir sinensis. This study aimed to investigate the mechanisms of Cd-induced intestinal inflammation in Eriocheir sinensis and to identify potential therapeutic agents. MethodsHistology, enzyme activity, and gene expression detection were combined to investigate the promoting effect of Cd on the exacerbation of intestinal inflammation in Eriocheir sinensis. Transcriptome sequencing was performed to analyze the critical signaling pathways regulating intestinal inflammation in Eriocheir sinensis. ResultsTranscriptome analysis confirmed that the Toll-like receptor pathway is critical in this process. TLR4-IN-C34, a specific inhibitor of TLR4, was identified as a potential treatment for intestinal inflammation. In vivo results demonstrated that TLR4-IN-C34 effectively reduced the severity of Cd-induced intestinal inflammation in Eriocheir sinensis. The tissue morphology of the intestine, gills, and hepatopancreas of Eriocheir sinensis improved, showing a significant decrease in inflammatory factors and apoptotic genes, along with enhanced antioxidant activity. ConclusionsIn conclusion, this study indicates that the water pollutant Cd exacerbates intestinal inflammation in Eriocheir sinensis, and TLR4-IN-C34 regulates the Toll-like receptor pathway in treating intestinal inflammation. This research provides valuable insights into the management of intestinal inflammation and the sustainable cultivation of Eriocheir sinensis.