Carp Muscle Research Articles

The mechanism of improving the flavor quality of bighead carp (Aristichthys nobilis) by the short-term micro-flowing water treatment

The short-term micro-flowing water treatment (STMF) has been proven to improve the taste quality of bighead carp. However, few studies have focused on its impact on the aroma quality of bighead carp muscle and the underlying mechanism. This study investigated the effect of STMF on the aroma quality of bighead carp muscle using UPLC–MS/MS-based metabolomics and gas chromatography–mass spectrometry (SAFE–GC–MS) combined with semi-quantitative methods. A total of 56 volatile compounds were found in the bighead carp muscle by SAFE–GC–MS. During the STMF, the contents of hexanal and (E,E)-2,4-heptadienal decreased significantly, which decreased by 24.09 % and 20.80 % after 6 days of the STMF, respectively. However, the contents of (E)-2-octenal and (E)-2-nonenal showed a trend of rising first and then falling, with maximum values at the 6th day of the STMF. The Pearson’s correlation coefficient showed a good correlation between some sensory attributes and aroma compounds. The fatty acid, amino acid, and glutathione metabolism of bighead carp muscle were significantly changed after 2 days of the STMF, with the contents of carnitine and acylcarnitine increased and then the contents of glutamic acid and glutamine increased. The improvement of flavor quality could be related to metabolism of carnitine, glutamic acid, glutamine, and glutathione. This study may help to understand the mechanism of STMF in enhancing the aroma quality of aquatic products.

P22-04 Health risk assessment of toxic metals (Cd, Hg, Pb) in common carp muscle tissue

P22-04 Health risk assessment of toxic metals (Cd, Hg, Pb) in common carp muscle tissue

From texture to structure: The key role of caspase-3 on grass carp myofibrillar protein during postmortem storage

The integrity of myofibrillar proteins during the initial post-mortem storage phase critically determines the shelf-life of fish, profoundly affecting consumer acceptance and market value. This research investigates the degradation of grass carp muscle texture and structure triggered by caspase-3-induced apoptosis, a key factor influencing early storage quality deterioration. By inhibiting endogenous caspase-3, the study tracks changes in apoptosis levels, muscle texture, microstructural integrity, protein organizational structure, and amino acid profiles. Apoptosis was found to peak between 48 and 72h post-mortem, during which caspase-3 activity led to significant muscle softening. This softening is attributed to disruptions in crucial structural components such as the Z-line and M-line, culminating in extensive degradation of myofibrillar proteins. Furthermore, protein structure modeling demonstrated that caspase-3 cleavage at ASP187 critically destabilizes the α-helix structure, underlining the enzyme's pivotal role in the early post-mortem softening of fish muscle. These insights provide a foundational understanding of the biochemical processes that underpin early quality loss in stored fish, offering potential targets for interventions aimed at enhancing fish storage outcomes and extending shelf life in the aquaculture industry.

Dynamic changes in postmortem quality of grass carp (Ctenopharyngodon idella) muscle: From the perspectives of muscle degradation and flavor evolution

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A new insight on alleviating the inhibitory effect of aflatoxin B1 on muscle development in grass carp (Ctenopharyngodon idella): the effect of 4-methylesculetin in vivo and in vitro

Aflatoxin B1 (AFB1), an important fungal toxin, exists mainly in plant feed ingredients and animals consuming feed contaminated with AFB1 will have reduced growth and impaired health condition mainly due to oxidative stress and reduced immunity. Our previous study found that AFB1 caused oxidative damage and inhibited muscle development of zebrafish. 4-methylesculetin (4-ME), a coumarin derivative, is now used in biochemistry and medicine widely because of its antioxidant function. Whether 4-ME could alleviate the inhibition of muscle development in grass carp induced by AFB1 has not been reported. In this experiment, 720 healthy grass carp (11.40 ± 0.01 g) were randomly divided into 4 groups with 3 replicates of 60 fish each, including control group, AFB1 group (60 μg/kg diet AFB1), 4-ME group (10 mg/kg diet 4-ME), and AFB1+4-ME group (60 μg/kg diet AFB1 + 10 mg/kg 4-ME diet), for a 60 d growth experiment. In vitro, we also set up 4 treatment groups in grass carp primary myoblast, including control group, AFB1 group (15 μmol/L AFB1), 4-ME group (0.5 μmol/L 4-ME) and AFB1+4-ME group (15 μmol/L AFB1+0.5 μmol/L 4-ME). The results showed that dietary AFB1 decreased growth performance of grass carp, damaged the ultrastructure and induced oxidative damage in grass carp muscle, and significantly decreased the mRNA and protein expression levels of myogenin (MyoG), myogenic differentiation (MyoD), myosin heavy chain (MYHC), as well as the protein expression levels of laminin β1, fibronectin and collagen Ⅰ (P < 0.05), significantly activated the protein expression levels of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and phosphorylate-38mitogen-activated protein kinase (p38 MAPK) both in grass carp muscle and grass carp primary myoblast (P < 0.05). Supplementation of AFB1 with 4-ME significantly improved the growth performance inhibition and alleviated the muscle fiber development inhibition and extracellular matrix (ECM) degradation in grass carp induced by AFB1. The present results revealed that supplementation of AFB1 contaminated feed with 4-ME reduced the inhibition of growth and muscle development by alleviating AFB1-induced ECM degradation in grass carp, which might be related to the p38 MAPK/uPA/MMP/ECM pathway. The results implied that 4-ME could be used as a valuable mycotoxin scavenger in animal feed.

Microfluidic Chip Coupled with MALDI-TOF MS for Multitarget Detection of Allergens in Crucian Carp (Carassius auratus).

The goal of the present study was to establish a rapid, simple method for simultaneous allergy testing of sera from multiple fish-allergic patients. Sera from fish-allergic patients were pooled and used for capturing allergens in fish muscle of crucian carp (Carassius auratus), which was studied as a fish model. Sarcoplasmic proteins of crucian carp (Carassius auratus) were extracted for the analysis of allergens. Anti-human IgE antibody-functionalized magnetic beads were utilized to collect IgE antibodies from human pooled sera. The isolation of allergenic proteins was immunomagnetically performed in microfluidic channels, and the elution of the captured allergenic proteins was done with 5% (v/v) acetic acid aqueous solution. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and peptide mass fingerprinting were used for the analysis of tryptic digests of eluted proteins. Ten potential allergenic proteins were identified from crucian carp (Carassius auratus). The present protocol provides a rapid, efficient, and simple method for simultaneous detection of multiple allergens, based on multitargeted antibodies from pooled sera of allergic patients. The constructed multiple antibody-modified MBs can be applied for the deallergenicity of food matrices. The efficiency of allergen detection can be greatly improved, with promising application in allergen discovery and filtration for other muscle-based foods.

ROS-Induced Autophagy of Skeletal Muscle Confers Resistance of Rice Flower Carp (Cyprinus carpio) to Short-Term Fasting.

Starvation is one of the main stresses for fish due to food shortage, the evasion of predators, and intraspecific competition. This research evaluated the impact of brief fasting periods on reactive oxygen species (ROS) levels, antioxidant response, mRNA expression of antioxidants, autophagy-related signaling genes, and autophagosome development in the muscle tissue of rice flower carp. Following a three-day fasting period, the levels of ROS and MDA rose. Additionally, after 3 d of fasting, there was a notable upregulation of NRF2 and significant increases in the levels of GSH and the activities of enzymes such as SOD, CAT, GST, GR, and GPX, while the expression of the autophagy marker gene LC3B did not change (p < 0.05). After 7 d of fasting, the content of the ROS, the activity of SOD and GR, and the GSH content reached the maximum (p < 0.05). Concurrently, there was a significant rise in the quantity of autophagosomes. An RT-qPCR analysis revealed that seven d of starvation significantly elevated the mRNA expression of genes associated with the initiation and expansion of autophagosome membranes, vesicle recycling, and cargo recruitment, including ULK1, BECLIN1, LC3B, ATG3, ATG4B, ATG4C, ATG5, ATG9, and P62. After feeding resumed for 3 d, the mRNA level of BECLIN1, ATG3, ATG4B, ATG4C, ATG5, LC3B, and P62 still remained at a high level. The LC3II protein reached its highest level. All autophagy-related gene expression decreased in the 7-day resumed feeding group. Our data implied that short-term fasting can cause oxidative stress and disrupt the antioxidant system first and then induce autophagy in the muscles of rice flower carp. These findings shed light on how fasting affects muscle homeostasis in fish. ROS-induced autophagy of the skeletal muscle may confer the resistance of rice flower carp to short-term fasting.

Genome-wide association analysis identifies genetic variants associated with muscle fatty acids and amino acids in grass carp (Ctenopharyngodon idella)

The composition and content of fatty acids (FAs) and amino acids (AAs) are important nutritional and sensory traits in aquaculture fish. To meet increasing demand while retaining quality, genetic selection in breeding programs is urgently needed to improve these traits. In this study, we performed the genome-wide association study (GWAS) to identify genetic variants and candidate genes potentially linked to FA and AA compositions in grass carp muscle. We focused on key dietary components, including unsaturated FAs and essential AAs. Through profiling of total FA and AA contents, we identified strong positive correlations among the compositions of most FAs and AAs. From our GWAS panel, 4,913,199 high-quality single nucleotide polymorphisms (SNPs) were identified across the genome, of which 32 SNPs linked to 18 candidate genes were significantly associated with FA levels, and 202 SNPs linked to 115 candidate genes associated with AA contents. In addition, we categorized our sequencing population by region and detected allele frequencies of SNPs across four geographic locations. Notably, four FA-associated SNPs and 28 AA-associated SNPs exhibited geographic specificity. These results offered valuable insights into the complex genetic basis of FA and AA metabolism and deposition. Furthermore, this work provides potential genetic markers for selective breeding aimed at enhancing flesh quality in the economically important fish species, grass carp.

Microelements, Fatty Acid Profile, and Selected Biomarkers in Grass Carp (Ctenopharyngodon idella) Muscle Tissue: Seasonal Variations and Health Risk Assessment

AbstractThe study assesses associations between microelement levels, fatty acid composition, and oxidative stress markers in grass carp muscle in the summer and autumn seasons. Additionally, various factors were considered, including the estimated daily intake (EDI), target hazard quotient (THQ), total THQ (TTHQ), and metal pollution index (MPI), to evaluate potential health risks for consumers. The microelements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, Se, Sr, and Zn) were determined using inductively coupled plasma optical emission spectrometry (ICP-OES), and total mercury was determined using cold-vapor atomic absorption spectroscopy (CV-AAS). Fatty acid profiling was realized using gas chromatography (GC) detection with a flame ionization detector (FID). The overall tendency of microelement levels was as follows: Fe &gt; Zn &gt; Al &gt; Sr &gt; Ba &gt; Ni &gt; Se &gt; Cr&gt; Cu &gt; Mn &gt; Pb &gt; As &gt; Li &gt; Hg; &lt;LOQ (below limit of quantification): Cd, and Co. The correlation analysis between concentrations of trace elements (Al, Ba, Cr, Cu, Mn, Li, Sr, Zn, and Hg) and the fatty acids (C16:0, C16:1, C18:1n9c, C18:2n6c, C20:4n6c, EPA, and DHA), as well as between Al, Ba, Fe, or Hg and oxidative stress markers (superoxide dismutase—SOD, glutathione peroxidase—GPx, or total antioxidant status—TAS), revealed statistically significant interactions in different seasons. THQ values were lower than 1; TTHQ values ranged from 0.27 to 0.76. The main toxic elements forming TTHQ were Hg and Ni (49%). The calculated health risk assessment indices indicate a low concentration of observed elements and low risks associated with the consumption of grass carp muscle from the tested location, although concentrations and THQ of mercury and nickel may be of slight concern.

Identification of hub genes in meat quality of grass carp (Ctenopharyngodon idellus) fed with faba bean by muscle tissue transcriptomic analysis

Crisp grass carp is a type of grass carp (Ctenopharyngodon idella) that has been fed faba beans. Flesh quality and expression of muscle quality-related genes in muscle of grass carp were evaluated. Compared with ordinary grass carp, 1901 differentially expressed genes (DEGs) were up-regulated and 1628 DEGs were down-regulated in crisp grass carp. The GO analysis results showed that the DEGs were enriched in ribosomes and proteins. Kyoto Encyclopaedia of genes and genomes (KEGG) pathway analysis results showed that amino acid metabolism was closely related to meat quality. COX3, ACADS, ACAT1, ECHS1, EHHADH, HADHAA, HADH, HMGCL, MCCC1 and MCCC2 were the top 10 hub genes most closely associated with other nodes and showed a strong positive correlation. Hardness was positively correlated with the COX3, ECHS1, ACADS, ACAT1, HADHA, HADH, HMGCL and MCCC1. These results have been demonstrated to play important roles in clarifying the molecular mechanism of muscle firmness increase in crisp grass carp.

Aflatoxin B1 decreased flesh flavor and inhibited muscle development in grass carp (Ctenopharyngodon idella)

In nature, aflatoxins, especially aflatoxin B1 (AFB1), are the common mycotoxins, which cause serious health problems for humans and animals. This paper aimed to study the effects of AFB1 on flesh flavor and muscle development of grass carp (Ctenopharyngodon idella) and its mechanism. There were 1440 individual fish in total, with 6 treatments and each treatment replicated 3 times. The 6 treatments were fed a control diet with different doses of AFB1 (0.04, 29.48, 58.66, 85.94, 110.43 and 146.92 μg/kg diet) for 60 d. AFB1 increased myofiber diameter, as well as decreased myofiber density of grass carp muscle (P < 0.05). The contents of free amino acid decreased gradually (P < 0.05) as dietary AFB1 increased in the muscle of grass carp. The levels of reactive oxygen species, malonaldehyde and protein carbonyl (PC) were increased (P < 0.05) with the dietary AFB1 increased. The levels of antioxidant enzyme (glutathione peroxidase, glutathione, glutathione reductase, total antioxidant capacity, anti-superoxide anion, and anti-hydroxyl radical) were decreased (P < 0.05) with the dietary AFB1 increased. In addition, dietary AFB1 decreased the content of collagen, and downregulated the mRNA and protein levels of transforming growth factor-β (TGF-β)/Smads signaling pathway in grass carp muscle (P < 0.05). The mRNA and protein levels of myogenic regulatory factors were downregulated in grass carp muscle (P < 0.05). Furthermore, the activities of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) were increased (P < 0.05), and the protein levels of phosphorylate-38 mitogen-activated protein kinase (p-p38MAPK), phosphorylate-c-Jun N-terminal kinase, urokinase-type plasminogen activator (uPA), MMP-2 and MMP-9 were upregulated (P < 0.05), but collagen Ⅰ, laminin β1 and fibronectin were downregulated (P < 0.05) with the dietary AFB1 increased in the muscle of grass carp. Based on the results of this study, we can draw the following conclusion: dietary AFB1 might damage flesh flavor and inhibit the muscle development through MAPK/uPA/MMP/extracellular matrix (ECM) signaling pathway in grass carp. Moreover, the recommended safe limit of AFB1 in feed is no more than 26.77 μg/kg diet according to the PC levels in grass carp muscle.

(−)-Epigallocatechin-3-O-gallate or (−)-epicatechin enhances lipid catabolism and antioxidant defense in common carp (Cyprinus carpio L.) fed a high-fat diet: Mechanistic insights from the AMPK/Sirt1/PGC-1α signaling pathway

Long-term high-fat diets (HF) lead to lipid accumulation and an oxidative stress response, which deteriorates the chemical and physical characteristics of fish muscle. Green tea extracts, such as (−)-epigallocatechin-3-O-gallate (EGCG) and (−)-epicatechin (EC), have been found to regulate antioxidant ability and lipid metabolism. However, the effects of EGCG and EC on alleviating oxidative stress and lipid metabolism disorders caused by HF are unclear. Furthermore, the underlying mechanisms remain unknown. In this study, a total of 360 carp (average weight: 9.75 ± 0.09 g) were provided with four experimental diets: a control diet (CN, 6.15% dietary lipids), a high-fat diet (HF, 14.05% dietary lipids), HF supplemented with EGCG (HF + EGCG, 14.05% dietary lipids +50 mg/kg EGCG), and a HF diet supplemented with EC (HF + EC, 14.05% dietary lipids +1000 mg/kg EC) for a duration of 84 days. The results indicated that EGCG or EC ameliorated the negative effects of the HF diet on muscle tissue. Apart from muscle physical characteristics, EGCG decreased yellowness (b*), redness (a*), and dripping loss (P < 0.05). Apart from muscle nutritional composition and antioxidant status, EC mitigated the reduction in protein levels in the muscle induced by the HF diet. Similarly, EGCG and EC mitigated the excessive accumulation of lipids and reactive oxygen species (ROS) in the muscle induced by the HF diet (P < 0.05). Further study showed that EGCG or EC facilitated the phosphorylation of AMP-activated protein kinase (AMPK) and increased silent information regulator 1 (Sirt1) and PPARγ coactivator-1 alpha (PGC-1α) expression in muscle. Taken together, the results of this study revealed that EGCG or EC enhance lipid metabolism and antioxidant capacity in the muscle of common carp (Cyprinus carpio L.) via the AMPK/Sirt1/PGC-1α pathway.

GCN2-eIF2α signaling pathway negatively regulates the growth of triploid crucian carp

GCN2-eIF2α signaling pathway plays crucial roles in cell growth,development, and protein synthesis. However, in polyploid fish, the function of this pathway is rarely understood. In this study, genes associated with the GCN2-eIF2α pathway (pkr, pek, gcn2, eif2α) are founded lower expression levels in the triploid crucian carp (3nCC) muscle compared to that of the red crucian carp (RCC). In muscle effect stage embryos of the 3nCC, the mRNA levels of this pathway genes are generally lower than those of RCC, excluding hri and fgf21. Inhibiting gcn2 in 3nCC embryos downregulates downstream gene expression (eif2α, atf4, fgf21), accelerating embryonic development. In contrast, overexpressing of eif2α can alter the expression levels of downstream genes (atf4 and fgf21), and decelerates the embryonic development. These results demonstrate the GCN2-eIF2α pathway's regulatory impact on 3nCC growth, advancing understanding of fish rapid growth genetics and offering useful molecular markers for breeding of excellent strains.

Seasonal variation in the concentration of potentially toxic elements in fish from El Tunal river, Durango, Mexico: Possible implications for human health

Environmental pollution is a major problem worldwide. One of the major health issues is the consumption of potentially toxic elements through fish intake, particularly in urban areas. Therefore, it is necessary to assess the human health risks of fish consumers. This study aims to determine concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn in the liver and muscle of freshwater carp (Cyprinus carpio) caught in El Tunal River, Durango, Mexico. Carps were collected in dry (n = 7) and rainy (n = 10) seasons. The highest concentrations of all elements were found in the liver, where As and Zn (4.83 and 6.51 µg/g w/w, respectively) were predominant. Meanwhile, As, Cr, and Zn (1.00, 1.12, and 1.09 µg/g w/w, respectively) were predominant in muscle. The concentrations of As, Cd, Cr, Pb, and Zn had significant differences between seasons (p &lt; 0.05), showing that during the rainy season the concentration of elements in the river, and hence in fish tissues, was reduced. Elements in edible tissue were below the levels allowed in Mexico and by international agencies. The mean and total target hazard quotients were below 1, indicating a minor risk to human health. Based on this study, fish consumption does not represent a risk to human health; however, it is necessary to continue monitoring pollutants since their accumulation can increase over time.

New sight in arginine-improved flesh quality: Role of MRFs, cyclins, and WNT signaling in grass carp (Ctenopharyngodon idellus)

In this study, we investigated the functional roles and mechanisms of arginine in improving the muscle quality of sub-adult grass carp. We divided 450 healthy fish (661.60 ± 1.00 g) into six groups and fed them separate diets with increasing levels of arginine (3.51, 7.01, 10.51, 14.01, 17.51, and 21.01 g/kg) for 63 days. The results showed that optimal dietary arginine levels promoted grass carp growth and improved muscle lipid content, shear force (hardness), pH, hydrolyzed amino acid contents, and the chemical score of essential amino acids (protein quality). Suitable dietary arginine levels also decreased the proportion of hypertrophic fibers and increased the proportion of hyperplastic fibers. Furthermore, appropriate arginine supplementation increased the expression levels of MyoD, MyoG, Myf5, MRF4, MyHC, cyclin D1, cyclin B, cyclin E, WNT1, WNT3a, and β-catenin and decreased the expression levels of MSTN and GSK3β. In conclusion, appropriate arginine levels in the diet (10.51–14.01 g/kg) may promote the growth and muscle quality of grass carp while increasing the proportion of hyperplasia fibers and decreasing the proportion of hypertrophic fibers probably by regulating the WNT/β-catenin pathway to increase the expression levels of MRFs and cyclins. This study offers novel insights into the regulatory role of arginine in muscle fiber growth, which can facilitate the improvement of grass carp muscle quality.

The influence of ultrafine zinc particles and phytobiotic supplement based on essential oils on the growth and elemental composition of carp muscle tissue

The influence of ultrafine zinc particles and phytobiotic supplement based on essential oils on the growth and elemental composition of carp muscle tissue

Eicosapentaenoic acid (EPA) improves grass carp (Ctenopharyngodon idellus) muscle development and nutritive value by activating the mTOR signaling pathway.

Skeletal muscle is the mainly edible part of fish. Eicosapentaenoic acid (EPA) is a crucial nutrient for fish. This study investigated the effect of EPA on the muscle development of grass carp along with the potential molecular mechanisms in vivo and in vitro. Muscle cells treated with 50 μM EPA in vitro showed the elevated proliferation, and the expression of mammalian target of rapamycin (mTOR) signaling pathway-related genes was upregulated (P < 0.05). In vivo experiments, 270 grass carp (27.92 g) were fed with one of the three experimental diets for 56 days: control diet (CN), 0.3% EPA-supplement diet (EPA), and the diet supplemented with 0.3% EPA and 30 mg/kg rapamycin (EPA + Rap). Fish weight gain rate (WGR) was improved in EPA group (P < 0.05). There was no difference in the viscerosomatic index (VSI) and body height (BH) among all groups (P > 0.05), whereas the carcass ratio (CR) and body length in the EPA group were obviously higher than those of other groups (P < 0.05), indicating that the increase of WGR was due to muscle growth. In addition, both muscle fiber density and muscle crude protein also increased in EPA group (P < 0.05). The principal component analysis showed that total weight of muscle amino acid in EPA group ranked first. Dietary EPA also increased protein levels of the total mTOR, S6k1, Myhc, Myog, and Myod in muscle (P < 0.05). In conclusion, EPA promoted the muscle development and nutritive value via activating the mTOR signaling pathway.

Polyethylene microplastics induced inflammation via the miR-21/IRAK4/NF-κB axis resulting to endoplasmic reticulum stress and apoptosis in muscle of carp

As a widespread environmental pollutant, microplastics pose a great threat to the tissues and organs of aquatic animals. The carp's muscles are necessary for movement and survival. However, the mechanism of injury of polyethylene microplastics (PE-MPs) to carp muscle remains unclear. Therefore, in this study, PE-MPs with the diameter of 8 μm and the concentration of 1000 ng/L were used to feed carp for 21 days, and polyethylene microplastic treatment groups was established. The results showed that PE-MPs could cause structural abnormalities and disarrangement of muscle fibers, and aggravate oxidative stress in muscles. Exposure to PE-MPs reduced microRNA (miR-21) in muscle tissue, negatively regulated Interleukin-1 Receptor Associated Kinase 4 (IRAK4), activated Nuclear Factor Kappa-B (NF-κB) pathway, induced inflammation, and led to endoplasmic reticulum stress and apoptosis. The present study provides different targets for the prevention of muscle injury induced by polyethylene microplastics.

Postmortem Muscle Proteome Characteristics of Silver Carp (Hypophthalmichthys molitrix): Insights from Full-Length Transcriptome and Deep 4D Label-Free Proteomic.

The coverage of the protein database directly determines the results of shotgun proteomics. In this study, PacBio single-molecule real-time sequencing technology was performed on postmortem silver carp muscle transcripts. A total of 42.43 Gb clean data, 35,834 nonredundant transcripts, and 15,413 unigenes were obtained. In total, 99.32% of the unigenes were successfully annotated and assigned specific functions. PacBio long-read isoform sequencing (Iso-Seq) analysis can provide more accurate protein information with a higher proportion of complete coding sequences and longer lengths. Subsequently, 2671 proteins were identified in deep 4D proteomics informed by a full-length transcriptomics technique, which has been shown to improve the identification of low-abundance muscle proteins and potential protein isoforms. The feature of the sarcomeric protein profile and information on more than 30 major proteins in the white dorsal muscle of silver carp were reported here for the first time. Overall, this study provides valuable transcriptome data resources and the comprehensive muscle protein information detected to date for further study into the processing characteristic of early postmortem fish muscle, as well as a spectral library for data-independent acquisition and data processing. This batch of muscle-specific dependent acquisition data is available via PRIDE with identifier PXD043702.

Health Risks Associated with the Concentration of Heavy Metals in Sediment, Water, and Carp Reared in Treated Wastewater from a Slaughterhouse

The use of purified slaughterhouse wastewater in carp ponds, and the use of wastewater from the pond for the irrigation of agricultural fields, was the basis for the construction of an integrated system of agricultural production as a sustainable solution for the food and fish production industries. The negative side of such integrated production systems is the concern related to the safety of fish meat produced in such a system. The aim of this research was to determine the concentration of heavy metals and metalloids in the wastewater from the slaughterhouse, in the pond water and sediment, in the carp tissue and in the water leaving the pond, and to evaluate the effectiveness of the integrated system and the safety of the produced fish. Sampling was carried out in spring and autumn. The mean concentrations in all water samples (µg/L) were: As (12–125), Cd (0.12–4.2), Hg (1.14–14.21), Pb (&lt;0.1–17.2), Cu (&lt;0.1–44.6), Fe (17.02–425.2) and Zn (2.91–186.2), with the highest numbers in the wastewater, where it was above the prescribed limit values for the wastewater discharged from the slaughterhouses into natural recipients in both samplings. The efficiency of the wastewater treatment plant for heavy metals and metalloids was very high, in the range of 87% to 98%. The water from the pond corresponded to class 3 in terms of the concentration of heavy metals and metalloids both in spring and autumn, and can be used freely for breeding cyprinid fish species. The water from the irrigation canal corresponded to class 2/3 and can be used for irrigation. The mean concentrations of heavy metals and metalloids in the sediments (mg/kg) were: As (3.00–4.88), Cd (0.16–0.96), Hg (0.21–1.47), Pb (0.77–2.29), Cu (49.60–60.90), Fe (3.94–5.32) and Zn (92.8–115.20). The content of heavy metals in different organs of carp differed significantly depending on the season. The trend of heavy metal accumulation in common carp muscles in spring was: Zn &gt; Fe &gt; Cu &gt; Pb &gt; Hg &gt; Cd &gt; As, and in autumn: Zn &gt; Fe &gt; Cu &gt; Pb &gt; As &gt; Cd &gt; Hg. Metal concentrations in the examined fish samples were far below the WHO guidelines. It can be concluded that carp produced in a pond supplied with purified wastewater from the slaughterhouse industry, in terms of the concentration of residues of the tested heavy metals and metalloids, is safe for human consumption.