RESUMO
The efficacy of phoxim in treating bacterial sepsis in silver carp is significant, yet its underlying mechanism remains elusive. This study aimed to establish a model of Aeromonas veronii infection in silver carp and subsequently treat the infected fish with 10 µg/L phoxim. Kidney and intestine samples from silver carp were collected for transcriptome analysis and assessment of intestinal microbial composition, with the aim of elucidating the mechanism underlying the efficacy of phoxim in treating bacterial sepsis in silver carp. The results of transcriptome and intestinal microbial composition analysis of silver carp kidney indicated that A. veronii infection could up-regulate the expression of il1ß, il6, nos2, ctsl, casp3 et al., which means, signifying that the kidney of silver carp would undergo inflammation, induce apoptosis, and alter the composition of intestinal microorganisms. Phoxim immersion might enhance the energy metabolism of silver carp and change its intestinal microbial composition, potentially elevating the antibacterial infection resistance of silver carp. These findings may contribute to an understanding of how phoxim can effectively treat bacterial sepsis in silver carp.
Assuntos
Carpas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Compostos Organotiofosforados , Animais , Carpas/imunologia , Doenças dos Peixes/imunologia , Compostos Organotiofosforados/farmacologia , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Aeromonas veronii/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
As a major component of the extracellular matrix, collagen has been used as a biomaterial for many purposes including tissue engineering. Commercial collagen derived from mammals is associated with a risk of prion diseases and religious restrictions, while fish-derived collagen can avoid such issues. In addition, fish-derived collagen is widely available and low-cost; however, it often suffers from poor thermal stability, which limits its biomedical application. In this study, collagen with a high thermal stability was successfully extracted from the swim bladder of silver carp (Hypophthalmichthys molitrix) (SCC). The results demonstrated that it was a type I collagen with high purity and well-preserved triple-helix structure. Amino acid composition assay showed that the amounts of threonine, methionine, isoleucine and phenylalanine in the collagen of swim bladder of silver carp were higher than those of bovine pericardium. After adding salt solution, swim-bladder-derived collagen could form fine and dense collagen fibers. In particular, SCC exhibited a higher thermal denaturation temperature (40.08 °C) compared with collagens from the swim bladder of grass carp (Ctenopharyngodon idellus) (GCC, 34.40 °C), bovine pericardium (BPC, 34.47 °C) and mouse tail (MTC, 37.11 °C). Furthermore, SCC also showed DPPH radical scavenging ability and reducing power. These results indicate that SCC presents a promising alternative source of mammalian collagen for pharmaceutical and biomedical applications.
Assuntos
Carpas , Colágeno Tipo I , Animais , Bovinos , Camundongos , Colágeno Tipo I/química , Bexiga Urinária/metabolismo , Colágeno/química , Sacos Aéreos/química , Mamíferos/metabolismoRESUMO
Fishes are an important component of human nutrition, mainly acting as source of essential fatty acids in the prevention of cardiovascular disorders. The increase in their consumption has led to a growth of fishes waste; therefore, the disposal and recycling of waste has become a key issue to address, in accordance with circular economy principles. The Moroccan Hypophthalmichthys molitrix and Cyprinus carpio fishes, living in freshwater and marine environments, were collected at mature and immature stages. The fatty acid (FA) profiles of liver and ovary tissues were investigated by GC-MS and compared with edible fillet tissues. The gonadosomatic index, the hypocholesterolemic/hypercholesterolemic ratio, and the atherogenicity and thrombogenicity indexes were measured. Polyunsaturated fatty acids were found to be abundant in the mature ovary and fillet of both species, with a polyunsaturated fatty acids/saturated fatty acids ratio ranging from 0.40 to 1.06 and a monounsaturated fatty acids/polyunsaturated fatty acids ratio between 0.64 and 1.84. Saturated fatty acids were found to be highly abundant in the liver and gonads of both species (range 30-54%), as well as monounsaturated fatty acids (range 35-58%). The results suggested that the exploitation of fish wastes, such as the liver and ovary, may represent a sustainable strategy for the achievement of high value-added molecules with nutraceutical potential.
Assuntos
Carpas , Ácidos Graxos , Humanos , Animais , Feminino , Peixes , Ácidos Graxos Insaturados , Gônadas , Fígado , Ácidos Graxos MonoinsaturadosRESUMO
Three mitochondrial DNA sequences (COI, ATP 8&6, and D-loop) were employed to assess the genetic diversity of four populations of silver carp from three main drainages in China, including the Yangtze River, the Amur River, and the Pearl River. As a result, 98 haplotypes were identified in combined sequences of COI, ATP8&6, and D-loop. A total of 196 variable sites and 116 parsimony-informative sites were observed. AMOVA based on assembled sequences indicated that 12.12% of the variation was among populations, while 87.88% of the variation was within populations. Additionally, the phylogenetic relationships of populations were depicted in a phylogenetic tree based on assembled sequences. Mismatch distribution analysis and the negative significant Fu's Fs values supported population expansion in all populations. Despite the high level of genetic diversity, the establishment of a state-level original breeding farm in the Amur River basin and the Pearl River basin may be an effective conservation strategy for the protection of local unique haplotypes.
Assuntos
Carpas , Animais , Carpas/genética , Filogenia , Variação Genética , Mitocôndrias/genética , DNA Mitocondrial/genética , Haplótipos , ChinaRESUMO
Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP), widely applied as flame retardant into a variety of products, can be physically leached out to the aquatic environment. Measurable values of TDCIPP have been found in the environment and within biota. Many toxicological assessments have shown that TDCIPP could cause developmental toxicity and oxidative stress in fish. In this study, we focused on the effects of TDCIPP on the growth and oxidative stress of an important commercial fish species in China, silver carp (Hypophthalmichthys molitrix). Fish larvae was exposed to environmentally relevant concentrations (0.05, 0.5, 5 and 50 µg/L) of TDCIPP for 7, 14 and 28 days. Simultaneously, the transcription levels of genes associated with the growth hormone/insulin-like growth factor (GH/IGF) axis and the antioxidative enzymes were examined. The body length and body mass of silver carp larvae decreased significantly only under exposure to 5 and 50 µg/L of TDCIPP at 14 days compared with the control group, while differences on those paraments were observed at 0.05, 0.5, 5 and 50 µg/L when larvae were exposed for 28 days. The observation evidenced the time- and dose- dependent growth inhibitions caused by TDCIPP on silver carp larvae. Exposure to TDCIPP also decreased the contents of GH and IGF1 in fish attended by significant down-regulation of gh and igf1. Moreover, TDCIPP up-regulated the expression of cat, sod1 and gstt followed by an increase of the activities of catalase (CAT) and superoxide dismutase (SOD) and the levels of malondialdehyde (MDA) and glutathione (GSH), but the activities of glutathione peroxidase (GPX) were decreased. These results suggested that growth inhibition and oxidative stress co-occurred in silver carp larvae after exposure to environmentally relevant concentrations of TDCIPP accompanied by the abnormal expression of genes which associated with the GH/IGF axis and antioxidative enzymes.
Assuntos
Carpas , Poluentes Químicos da Água , Animais , Carpas/genética , Carpas/metabolismo , Larva , Compostos Organofosforados/toxicidade , Estresse Oxidativo , Fosfatos/metabolismo , Poluentes Químicos da Água/metabolismo , Peixe-Zebra/metabolismoRESUMO
Hypophthalmichthys molitrix (silver carp) is phytoplanktivorous and is an economically and ecologically important fish species. As a well-known invasive species, a number of factors associated with the ecological adaptations of this species are largely unknown. Here, we present a chromosomal-level assembly of the species based on the PacBio Sequel II platform and Hi-C scaffolding technology. Based on the high-quality genome sequences and previous genome sequencing projects, a number of genes that were probably subject to positive selection reside in the genome of H. molitrix, and the last common ancestors of H. molitrix and H. nobilis were identified. Some of these genes may partially explain the mechanisms of H. molitrix for surviving damage due to toxic algae. Demographic history estimation suggests that the effective population size (EPS) of the species may have constantly increased along with the uplift of the Qinghai-Tibet Plateau, started to decline when quaternary glaciation started, and further declined during the Younger Dryas Period. Moreover, the introgression from H. nobilis to H. molitrix in North America was corroborated based on the whole-genome sequencing data, and the proportion of introgressed regions was estimated to be approximately 5.8%. Based on the high-quality assembly, the possible mechanisms by which H. molitrix adapts to its endemic and invaded locations were profiled.
Assuntos
Carpas , Cipriniformes , Animais , Mapeamento Cromossômico , Cromossomos/genética , Cipriniformes/genética , GenomaRESUMO
Effect of dietary with 100, 200, and 300 mg kg-1 glycyrrhizic acid (GA) on growth enhancer, blood physiology, digestive-antioxidant enzyme ability, innate-adaptive defense, and inflammatory cytokines induction was studied in silver carp, Hypophthalmichthys molitrix against vibriosis caused by Vibrio alginolyticus. Significant weight gain (WG), specific growth rate (SGR), and 100% survival rate (SR) was attained non-infected health (NiH) fish fed in control or all GA diets on 30, 45, and 60 days. Both NiH and V. alginolyticus challenged (VaC) fish treated with 200 mg GA diet significantly (P < 0.05) exhibited an enhancement in leucocytes value on 30, 45, and 60 days. Albumin (AB) or total proteins (TP) levels were significantly (P < 0.05) better in both groups fed 200 GA on 45 and 60 days. Malondialdehyde (MDA) and superoxide dismutase (SOD) activities were also substantial (P < 0.05) in both groups fed 200 mg GA on days 30, 45, and 60; whereas glutathione peroxidase (GPx) and catalase (CAT) activities were significantly (P < 0.05) better in both groups received 200 mg GA on days 45 and 60. Phagocytic (PC) and lysozyme (Lyz) activities significantly enhanced in both groups fed 200 or 300 mg GA on 45 and 60 days. Respiratory burst (RB), reactive oxygen species (ROS) and immunoglobulin (Ig) production significantly (P < 0.05) increased in both groups administered 200 or 300 mg GA. Growth hormone (GH) mRNA was up regulated in 200 mg GA trial on 45 days and in 200 or 300 mg GA treatments on 60 days. The IL-8 cytokine mRNA expression was up-regulated in both groups 200 and 300 mg GA on days 45 and 60, whereas TNF-α mRNA expression was increased in 200 mg GA. In addition, IL-10 cytokine mRNA expression was up regulated in 200 mg GA on 45 days whereas it was increased in both 200 mg and 300 mg GA trial on 60 days. The present study revealed that feeding fish 200 mg GA per kg diet demonstrated a better growth, digestive-antioxidant activity, innate-adaptive defense, and inflammatory cytokines induction than lower or higher dosage of GA in H. molitrix against V. alginolyticus.
Assuntos
Carpas , Doenças dos Peixes , Vibrioses , Ração Animal/análise , Animais , Antioxidantes , Citocinas/genética , Dieta/veterinária , Suplementos Nutricionais/análise , Ácido Glicirrízico , Imunidade Inata , RNA MensageiroRESUMO
Retinol-binding protein 4 (RBP4) is known as a highly conserved adipokine for immune activation. Aeromonas hydrophila (A. hydrophila) is the most common zoonotic pathogen in aquaculture, which causes serious economic losses to aquaculture, especially to bighead carp (Hypophthalmichthys nobilis, H. nobilis) and silver carp (Hypophthalmichthys molitrix, H. molitrix). Recent studies along with our previous findings have shown that synthetic oligodeoxynucleotides containing CpG motifs (CpG ODN) can play a good role in aquatic animals against infection. In order to clarify the relationship between CpG ODN and RBP4 under A. hydrophila infection, firstly, full-length RBP4 cDNAs from H. nobilis and H. molitrix were cloned. And characteristics of RBP4, including sequence and structure, tissue distribution and genetic evolution were analyzed. In addition, mRNA expression levels of RBP4, cytokine, toll-like receptors (TLRs), morbidity and survival rates of H. nobilis and H. molitrix were observed post CpG ODN immunization or following challenge. The results indicated that hn/hm_RBP4 (RBP4 genes obtained from H. nobilis and H. molitrix) had the highest homology with Megalobrama amblycephala. Distribution data showed that the expression level of hn_RBP4 mRNA was higher than that of hm_RBP4. After CpG ODN immunization followed by A.hydrophila challenge, significantly higher survival was observed in both carps, together with up-regulated RBP4 expression. Meanwhile, hn/hm_IL-1ß level was relatively flat (and decreased), hn/hm_IFN-γ, hn/hm_TLR4 and hn/hm_TLR9 levels increased significantly, but hn/hm_STRA6 showed no significant change, compared with control. Moreover, CpG ODN immunization could induce stronger immune protective responses (higher IFN-γ/gentle IL-1ß level and lower morbidity/higher survival rate) against A. hydrophila in H. nobilis, along with higher RBP4 level, when compared with that in H. molitrix. These results demonstrated that RBP4 was well involved in the immune protection of CpG ODN. Based on the results, we speculated that in the case of A. hydrophila infection, TLR9 signaling pathway was activated by CpG ODN. Subsequently, CpG ODN up-regulated RBP4, and RBP4 activated TLR4 signaling pathway. Then TLR4 and TLR9 synergistically improved the anti-infection responses. Our findings have good significance for improving resistance to pathogen infection in freshwater fish.
Assuntos
Carpas/genética , Carpas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Imunização/veterinária , Oligodesoxirribonucleotídeos/administração & dosagem , Proteínas Celulares de Ligação ao Retinol/genética , Aeromonas hydrophila/patogenicidade , Animais , Carpas/imunologia , DNA Complementar , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Oligodesoxirribonucleotídeos/imunologia , Proteínas Celulares de Ligação ao Retinol/química , Proteínas Celulares de Ligação ao Retinol/imunologia , Regulação para CimaRESUMO
The growth of cyanobacteria (blue-green algae) is a typical phenomenon in water bodies worldwide. The use of silver carp (Hypophthalmichthys molitrix) to reduce excessive phytoplankton development is controversial. In the case of cyanobacteria, many of which are toxic, understanding their possible digestion mechanism by fish is particularly desirable. A unique methodical approach, which consists of applying intestinal contents or extracts to a cyanobacteria culture, was used. Unicellular cyanobacteria (Cyanothece) were incubated in vitro with bile, contents of different parts of the intestinal tract, and cytosolic and microsomal extracts of the intestinal tissue of silver carp. The abundance of cyanobacteria decreased in all treatments containing either exclusively bile or its combination with intestinal contents. This research provides the first evidence of non-mechanical digestion of cyanobacteria by silver carp. Cyanobacteria incubated with intestinal contents or extracts reached mostly higher abundances than those incubated with the nutrient medium. The existence of non-mechanical digestion mediated via intestinal contents and extracts or its compensation connected with organic substance uptake is discussed.
Assuntos
Carpas/microbiologia , Cianobactérias , AnimaisRESUMO
Myxobolus gutturocola n. sp. was isolated from the throat of silver carp, Hypophthalmichthys molitrix, in Chongqing, China. Myxospore valves are unsymmetrical and smooth. Mature spores are ellipsoidal in frontal view, measuring 12.5 ± 0.2 µm (n = 25) in length, 8.4 ± 0.2 µm (n = 25) in width and 7.1 ± 0.2 µm (n = 25) in thickness. Each spore has two pyriform and unequal sizes polar capsules, the large one with 5.7 ± 0.2 µm in length × 3.6 ± 0.2 µm in width and the small one with 4.6 ± 0.2 µm in length × 2.6 ± 0.1 µm in width. Polar filaments are coiled seven or eight turns in the large polar capsule and four or five turns in the small polar capsule. The coils are arranged almost perpendicularly to the longitudinal axis of the polar capsule. Morphological analysis revealed that M. gutturocola n. sp. is distinct from related species of Myxobolus Bütschli, 1882. Molecular analysis has demonstrated that its SSU rDNA sequences do not match with any available sequences in GenBank. Phylogenetic analysis of the SSU rDNA sequences indicated this species clustered in a clade composed exclusively of parasites infecting the fishes of the Leucisini lineage and most closely related to Myxobolus pavlovskii isolated from the gill filaments of silver carp in Hungary.
Assuntos
Carpas/parasitologia , Doenças dos Peixes/parasitologia , Myxobolus/classificação , Doenças Parasitárias em Animais/parasitologia , Animais , China , DNA Ribossômico/química , DNA Ribossômico/genética , Myxobolus/anatomia & histologia , Myxobolus/genética , Faringe/parasitologia , FilogeniaRESUMO
Invasive silver carp are thriving within eutrophic environments in the United States, in part because of their highly efficient filter-feeding mechanism. Silver carp utilize modified gill rakers to capture a specific range of food; however, their greatly modified filtering morphology allows them to feed on phytoplankton and zooplankton ranging in size from 4 to 85â µm. The filtering apparatus of silver carp comprises rigid filtering plates where the outer anatomy of these plates is characterized by long parallel channels that change in orientation along the length of the plate. Here, we investigate the underlying morphology and concomitant hydrodynamics that support the filtration mechanisms of silver and bighead carp. Bighead carp are also invasive filter feeders, but their filtering apparatus is morphologically distinct from that of silver carp. Using 3D particle image velocimetry, we determined how particles and fluid interact with the surface of the gill rakers/plates. Filtering plates in silver carp induce strong directed vortical flow, whereas the filtering apparatus of bighead carp resulted in a type of haphazard cross-flow filtration. The organized vortical flow established by silver carp likely increased the number of interactions that the particle-filled water had with the filtering membrane. This strong vortical organization is maintained only at 0.75â bodyâ lengths s-1, and vortical flow is poorly developed and maintained at slower and faster speeds. Moreover, we found that absolute vorticity magnitude in silver carp is an order of magnitude greater than in bighead carp.
Assuntos
Carpas/anatomia & histologia , Carpas/fisiologia , Comportamento Alimentar , Hidrodinâmica , Animais , Modelos Biológicos , Boca/diagnóstico por imagem , Reologia , Movimentos da Água , Microtomografia por Raio-X/veterináriaRESUMO
Effects of cadmium (Cd) exposure on metal accumulation and energy metabolism of silver carp (Hypophthalmichthys molitrix) were studied during 14 days. The results showed that Cd accumulated in tissues of silver carp significantly with time and Cd concentration, as the order: liver > kidney > gill > muscle. The levels of muscle glycogen, triglyceride, and plasma triglyceride decreased significantly (p < 0.05). The levels of muscle protein, plasma glucose and lactate significantly increased during the first 8 days, and then all significantly decreased (p < 0.05). No significant alternations were observed in muscle cortisol, ATP and plasma protein (p > 0.05). The results indicate that the tissues' Cd concentrations and energy metabolism were altered by the presence of waterborne Cd, and silver carp mobilizes the muscle energy stores to cope with the increased energy demands for detoxication and repair mechanism induced by the exposure to waterborne Cd.
Assuntos
Cádmio/toxicidade , Carpas/fisiologia , Metabolismo Energético/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cádmio/metabolismo , Brânquias/metabolismo , Fígado/metabolismo , Músculos/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
The current study focuses on the detection and characterization of potentially pathogenic Aeromonas sobria from fish silver carp (Hypophthalmichthys molitrix). Assessment of clinical, microbiological, pathological and biochemical characteristics of A. sobria were taken into account in order to understand the epidemiology, frequency and occurrence of this infection. Clinically the infected fish (H. molitrix) was observed for various types of symptoms. A total of 33 colonies of A. sobria strain were isolated from 20 cultured H. molitrix, collected from controlled fish pond. Microscopic examination revealed that the strains were rod-shaped, Gram negative bacteria. The revealed percent probability identification of A. sobria from the biochemical characterization in VITEK system was 93% with gram negative (GN) card. The histopathology of Gills caused by this bacterium, A. sobria indicate haemorrhagic gill epithelia and epithelial hyperplasia. Lamelar epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium and hypertrophic epitheliocystis infected cells on gills of H. molitrix were observed during the present study.
Assuntos
Aeromonas/isolamento & purificação , Carpas/microbiologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Aeromonas/classificação , Aeromonas/genética , Aeromonas/patogenicidade , Animais , Infecções por Bactérias Gram-Negativas/microbiologia , VirulênciaRESUMO
Effects of acute exposure to sublethal waterborne cadmium (Cd) on energy homeostasis in filter-feeding fishes have rarely been studied. The response patterns of energy substances were investigated in juvenile silver carp (Hypophthalmichthys molitrix) exposed to sublethal waterborne Cd for 96 h. The results showed the 96hLC50 of Cd on juvenile silver carp was 1.723 mg/L. Sublethal acute exposure of Cd significantly affected the energy homeostasis of juvenile silver carp, including increase in plasma glucose and lactate, and decrease in plasma triglyceride, muscle glycogen and triglyceride and liver glycogen. The results indicated that glycogen and triglyceride prior to protein were mobilized to meet the increased demands for detoxication and repair mechanism to sublethal waterborne Cd exposure, and glycogen level depleted faster and restored slower in the liver than in the white muscle in juvenile silver carp.
Assuntos
Cádmio/toxicidade , Carpas/metabolismo , Fígado/metabolismo , Músculos/metabolismo , Animais , HomeostaseRESUMO
Bone morphogenetic protein 6 (BMP-6) is a constituent of the TGF-ß superfamily, known for its ability to stimulate bone and cartilage formation. The investigation of bmp6's involvement in the formation of intermuscular bones in fish has garnered significant attention in recent years. The rib cage is an important skeletal structure that plays a protective function for internal organs in fish. However, there has been limited research conducted on the effects of the bmp6 gene on rib development. Silver carp is one of four major fish in China, favoured for its affordability and tender muscle. Nevertheless, the presence of numerous intermuscular bones in silver carp significantly hinders the advancement of its palatability and suitability for processing. This study showcases the effective utilisation of CRISPR/Cas9 technology for the purpose of disrupting the bmp6 gene in silver carp, leading to the creation of chimeras in the P0 generation, marking the first instance of such an achievement. The chimeras exhibited complete viability, normal appearance, and partial intermuscular bones loss, with approximately 30% of them displaying rib bifurcation or bending. Subsequently, a transcriptome analysis on ribs of P0 chimeras and wild-type silver carp was conducted, leading to the identification of 934 genes exhibiting differential expression, of which 483 were found to be up-regulated and 451 were found to be down-regulated. The results of the KEGG analysis revealed that the "NF-kappa B signalling pathway", "Hippo signalling pathway", "osteoclast differentiation", and "haematopoietic cell lineage" exhibited enrichment and displayed a significant correlation with bone development. The up-regulated genes such as tnfα, fos, and ctgf in pathways may facilitate the proliferation and differentiation of osteoclasts, whereas the down-regulation of genes such as tgfb2 and tgfbr1 in pathways may hinder the formation and specialisation of osteoblasts, ultimately resulting in rib abnormalities. This study presents novel findings on the impact of bmp6 gene deletion on the rib development of silver carp, while simultaneously investigating the previously unexplored molecular mechanisms underlying rib defects in fish.
RESUMO
Plastic products and nutrients are widely used in aquaculture facilities, resulting in copresence of nanoplastics (NPs) released from plastics and microcystins (MCs) from toxic cyanobacteria. The potential effects of NPs-MCs coexposure on aquatic products require investigation. This study investigated the toxic effects of polystyrene (PS) NPs and MC-LR on the gut-liver axis of silver carp Hypophthalmichthys molitrix, a representative commercial fish, and explored the effects of the coexposure on intestinal microorganism structure and liver metabolic function using traditional toxicology and multi-omics association analysis. The results showed that the PS-NPs and MC-LR coexposure significantly shortened villi length, and the higher the concentration of PS-NPs, the more obvious the villi shortening. The coexposure of high concentrations of PS-NPs and MC-LR increased the hepatocyte space in fish, and caused obvious loss of gill filaments. The diversity and richness of the fish gut microbes significantly increased after the PS-NPs exposure, and this trend was amplified in the copresence of MC-LR. In the coexposure, MC-LR contributed more to the alteration of fish liver metabolism, which affected the enrichment pathway in glycerophospholipid metabolism and folic acid biosynthesis, and there was a correlation between the differential glycerophospholipid metabolites and affected bacteria. These results suggested that the toxic mechanism of PS-NPs and MC-LR coexposure may be pathological changes of the liver, gut, and gill tissues, intestinal microbiota disturbance, and glycerophospholipid metabolism imbalance. The findings not only improve the understanding of environmental risks of NPs combined with other pollutants, but also provide potential microbiota and glycerophospholipid biomarkers in silver carp.
Assuntos
Carpas , Cianobactérias , Toxinas Marinhas , Animais , Carpas/metabolismo , Microcistinas/análise , Microplásticos/metabolismo , Fígado/química , Cianobactérias/metabolismo , Glicerofosfolipídeos/metabolismo , Glicerofosfolipídeos/farmacologiaRESUMO
Multicopied mitogenome are prone to mutation during replication often resulting in heteroplasmy. The derived variants in a cell, organ, or an individual animal constitute a mitogene pool. The individual mitogene pool is initiated by a small fraction of the egg mitogene pool. However, the characteristics and relationship between them has not yet been investigated. This study quantitatively analyzed the heteroplasmy landscape, genetic loads, and selection strength of the mitogene pool of egg and hatchling in the silver carp (Hypophthalmichthys molitrix) using high-throughput resequencing. The results showed heteroplasmic sites distribute across the whole mitogenome in both eggs and hatchlings. The dominant substitution was Transversion in eggs and Transition in hatching accounting for 95.23%±2.07% and 85.38%±6.94% of total HP sites, respectively. The total genetic loads were 0.293±0.044 in eggs and 0.228±0.022 in hatchlings (P=0.048). The dN/dS ratio was 58.03±38.98 for eggs and 9.44±3.93 for hatchlings (P=0.037). These results suggest that the mitogenomes were under strong positive selection in eggs with tolerance to variants with deleterious effects, while the selection was positive but much weaker in hatchlings showing marked quality control. Based on these findings, we proposed a trans-generation dynamics model to explain differential development mode of the two mitogene pool between oocyte maturation and ontogenesis of offspring. This study sheds light on significance of mitogene pool for persistence of populations and subsequent integration in ecological studies and conservation practices.
Assuntos
Carpas , Genoma Mitocondrial , Animais , Carpas/genética , Heteroplasmia , Seleção Genética , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
This study investigated non-thermal pretreatment (cold plasma, CP) on the flavor (taste and odor) profiles of dried fish products. CP treatment of 5 min contributed to accumulation of umami nucleotides adenosine 5'-monophosphate (AMP) from 30.96 to 40.82 µg/g and inosine 5'-monophosphate (IMP) from 2009.29 to 2132.23 µg/g, and significant reduction of bitter hypoxanthine ribonucleoside (HxR) and hypoxanthine (Hx), respectively (P < 0.05) in the dried fish products. A noticeable enhancement in sweet glycine (from 429.41 to 490.03 mg/100 g) and umami glutamic acid (from 55.68 to 67.76 mg/100 g) accompanied with the CP treatment (P < 0.05) based on taste activity value (TAV > 1). And the characteristic odor volatiles (nonanal, hexanal and 1-octen-3-ol) were strengthened 2.13-, 2.16- and 2.17- folds, respectively (P < 0.05). The results of equivalent umami concentration and Gibbs free energy calculation, combining with the correlation analysis, indicate that nucleotides and free amino acids synergically enhanced the taste improvement of dried fish products. Moderate lipids oxidation favored the formation of characteristic volatiles. The CP pretreatment offered new strategies for enhancing flavor of dried fish products.
Assuntos
Carpas , Produtos Pesqueiros , Aromatizantes , Odorantes , Paladar , Animais , Odorantes/análise , Produtos Pesqueiros/análise , Carpas/metabolismo , Aromatizantes/química , Gases em Plasma/química , Humanos , Compostos Orgânicos Voláteis/química , Conservação de Alimentos/métodosRESUMO
Silver carp (Hypophthalmichthys molitrix) is a potential source for making surimi products. However, it has the disadvantages of bony structures, high level of cathepsines and muddy off-odor which is mainly caused by geosmin (GEO) and 2-methylisoborneol (MIB). These disadvantages make the conventional water washing process of surimi inefficient (low protein recovery rate, and high residual muddy off-odor). Thus, the effect of the pH-shifting process (acid-isolating process and alkali-isolating process) on the cathepsins activity, GEO content, MIB content, and gelling properties of the isolated proteins (IPs) was investigated, comparing it with surimi obtained through the conventional cold water washing process (WM). The alkali-isolating process greatly boosted the protein recovery rate from 28.8% to 40.9% (p < 0.05). In addition, it removed 84% GEO and 90% MIB. The acid-isolating process removed about 77% GEO and 83% MIB. The acid-isolated protein (AC) displayed the lowest elastic modulus (G'), the highest TCA-peptide content (90.89 ± 4.65 mg/g) and the highest cathepsin L activity (65.43 ± 4.91 U/g). The AC modori (60 °C for 30 min) gel also demonstrated the lowest breaking force (226.2 ± 19.5 g) and breaking deformation (8.3 ± 0.4 mm), indicating that proteolysis caused by the cathepsin deteriorated the gel quality of AC. The setting (40 °C for 30 min) considerably increased the breaking force (386.4 ± 15.7 g) and breaking deformation (11.6 ± 0.2 mm) of the gel made from the alkali-isolated protein (AK) (p < 0.05). In AC and AK gel, a clearly visible cross-linking protein band with a molecular weight greater than MHC was seen, demonstrating the presence of endogenous trans-glutaminase (TGase) activity, that improved the gel quality of AK. In conclusion, the alkali-isolating process was an effective alternative method for making water-washed surimi from silver carp.
RESUMO
Problems with silver carp protein (SCP) include a strong fishy odor, low gel strength of SCP surimi, and susceptibility to gel degradation. The objective of this study was to improve the gel quality of SCP. The effects of the addition of native soy protein isolate (SPI) and SPI subjected to papain-restricted hydrolysis on the gel characteristics and structural features of SCP were studied. The ß-sheet structures in SPI increased after papain treatment. SPI treated with papain was crosslinked with SCP using glutamine transaminase (TG) to form a composite gel. Compared with the control, the addition of modified SPI increased the hardness, springiness, chewiness, cohesiveness, and water-holding capacity (WHC) of the protein gel (p < 0.05). In particular, the effects were most significant when the degree of SPI hydrolysis (DH) was 0.5% (i.e., gel sample M-2). The molecular force results demonstrated that hydrogen bonding, disulfide bonding, and hydrophobic association are important molecular forces in gel formation. The addition of the modified SPI increases the number of hydrogen bonds and the disulfide bonds. Scanning electron microscopy (SEM) analysis showed that the papain modifications allowed the formation of a composite gel with a complex, continuous, and uniform gel structure. However, the control of the DH is important as additional enzymatic hydrolysis of SPI decreased TG crosslinking. Overall, modified SPI has the potential to improve SCP gel texture and WHC.