RESUMO
Sturgeon, with 4 times higher lipid content than silver carp (ubiquitously applied for surimi production in China), affects surimi gelling properties. However, how the flesh lipids affect gelling properties remains unclear. This study investigated how flesh lipids impact surimi gelling properties and elucidated the interaction mechanism between lipids and proteins. Results revealed yellow meat contains 7 times higher lipids than white meat. Stronger ionic protein-protein interactions were replaced by weaker hydrophobic forces and hydrogen bonds in protein-lipid interaction. Protein-lipid interaction zones encapsulated lipid particles, changing protein structure from α-helix to ß-sheet structure thereby gel structure becomes flexible and disordered, significantly diminishing surimi gel strength. Docking analysis validated fatty acid mainly binding at Ala577, Ile461, Arg231, Phe165, His665, and His663 of myosin. This study first reported the weakened surimi gelling properties from the perspective of free fatty acids and myosin interactions, offering a theoretical basis for sturgeon surimi production.
Assuntos
Proteínas de Peixes , Peixes , Géis , Lipídeos , Animais , Géis/química , Lipídeos/química , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Produtos Pesqueiros/análise , Interações Hidrofóbicas e Hidrofílicas , Ligação de Hidrogênio , Miosinas/química , Miosinas/metabolismo , Simulação de Acoplamento Molecular , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Carpas/metabolismo , Ligação ProteicaRESUMO
The Atlantic salmon is an extremely popular fish for its nutritional value and unique taste among several fish species. Researchers are focusing on the utilization of Atlantic salmon waste for generating protein hydrolysates rich in peptides and amino acids and investigating their health benefits. Several technological approaches, including enzymatic, chemical, and the recently developed subcritical water hydrolysis, are currently used for the production of Atlantic salmon waste protein hydrolysates. Hydrolyzing various wastes, e.g., heads, bones, skin, viscera, and trimmings, possessing antioxidant, blood pressure regulatory, antidiabetic, and anti-inflammatory properties, resulting in applications in human foods and nutraceuticals, animal farming, pharmaceuticals, cell culture, and cosmetics industries. Furthermore, future applications, constraints several challenges associated with industrial hydrolysate production, including sensory, safety, and economic constraints, which could be overcome by suggested techno processing measures. Further studies are recommended for developing large-scale, commercially viable production methods, focusing on eradicating sensory constraints and facilitating large-scale application.
Assuntos
Proteínas de Peixes , Hidrolisados de Proteína , Salmo salar , Animais , Salmo salar/metabolismo , Hidrolisados de Proteína/química , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Humanos , Hidrólise , Resíduos/análiseRESUMO
BACKGROUND: Thermal stress is a major environmental factor affecting fish development and survival. Common carp (Cyprinus carpio) are susceptible to heat stress in their embryonic and larval phases, but the thermal stress response of alternative splicing during common carp embryogenesis remains poorly understood. RESULTS: Using RNA-seq data from eight developmental stages and four temperatures, we constructed a comprehensive profile of alternative splicing (AS) during the embryogenesis of common carp, and found that AS genes and events are widely distributed among all stages. A total of 5,835 developmental stage-specific AS (SAS) genes, 21,368 temperature-specific differentially expressed genes (TDEGs), and 2,652 temperature-specific differentially AS (TDAS) genes were identified. Hub TDAS genes in each developmental stage, such as taf2, hnrnpa1, and drg2, were identified through protein-protein interaction (PPI) network analysis. The early developmental stages may be more sensitive to temperature, with thermal stress leading to a massive increase in the number of expressed transcripts, TDEGs, and TDAS genes in the morula stage, followed by the gastrula stage. GO and KEGG analyses showed that from the morula stage to the neurula stage, TDAS genes were more involved in intracellular transport, protein modification, and localization processes, while from the optic vesicle stage to one day post-hatching, they participated more in biosynthetic processes. Further subgenomic analysis revealed that the number of AS genes and events in subgenome B was generally higher than that in subgenome A, and the homologous AS genes were significantly enriched in basic life activity pathways, such as mTOR signaling pathway, p53 signaling pathway, and MAPK signaling pathway. Additionally, lncRNAs can play a regulatory role in the response to thermal stress by targeting AS genes such as lmnl3, affecting biological processes such as apoptosis and axon guidance. CONCLUSIONS: In short, thermal stress can affect alternative splicing regulation during common carp embryogenesis at multiple levels. Our work complemented some gaps in the study of alternative splicing at both levels of embryogenesis and thermal stress in C. carpio and contributed to the comprehension of environmental adaptation formation in polyploid fishes during embryogenesis.
Assuntos
Processamento Alternativo , Carpas , Desenvolvimento Embrionário , Resposta ao Choque Térmico , Animais , Carpas/genética , Carpas/embriologia , Carpas/metabolismo , Desenvolvimento Embrionário/genética , Resposta ao Choque Térmico/genética , Regulação da Expressão Gênica no Desenvolvimento , Perfilação da Expressão Gênica , Mapas de Interação de Proteínas , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismoRESUMO
BACKGROUND: Temperature is a crucial environmental determinant for the vitality and development of teleost fish, yet the underlying mechanisms by which they sense temperature fluctuations remain largely unexplored. Transient receptor potential (TRP) proteins, renowned for their involvement in temperature sensing, have not been characterized in teleost fish, especially regarding their temperature-sensing capabilities. RESULTS: In this study, a genome-wide analysis was conducted, identifying a total of 28 TRP genes in the mandarin fish Siniperca chuatsi. These genes were categorized into the families of TRPA, TRPC, TRPP, TRPM, TRPML, and TRPV. Despite notable variations in conserved motifs across different subfamilies, TRP family members shared common structural features, including ankyrin repeats and the TRP domain. Tissue expression analysis showed that each of these TRP genes exhibited a unique expression pattern. Furthermore, examination of the tissue expression patterns of ten selected TRP genes following exposure to both high and low temperature stress indicated the expression of TRP genes were responsive to temperatures changes. Moreover, the expression profiles of TRP genes in response to mandarin fish virus infections showed significant upregulation for most genes after Siniperca chuatsi rhabdovirus, mandarin fish iridovirus and infectious spleen and kidney necrosis virus infection. CONCLUSIONS: This study characterized the TRP family genes in mandarin fish genome-wide, and explored their expression patterns in response to temperature stress and virus infections. Our work will enhance the overall understanding of fish TRP channels and their possible functions.
Assuntos
Perciformes , Filogenia , Canais de Potencial de Receptor Transitório , Animais , Canais de Potencial de Receptor Transitório/genética , Canais de Potencial de Receptor Transitório/metabolismo , Perciformes/genética , Perciformes/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Família Multigênica , Genoma , Temperatura , Infecções por Vírus de DNA/genética , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/genética , Doenças dos Peixes/virologia , Regulação da Expressão Gênica , IridoviridaeRESUMO
Fatty acid-binding protein 1 (FABP1) plays an important role in regulating fatty acid metabolism in liver, which is a potential therapeutic target for diseases such as non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are not well defined. Using complementary experimental models, we discovered FABP1 induction in hepatocytes as a primary mediator of lipogenesis when exposed to fatty acids, especially saturated fatty acids (SFAs). In the feeding trial, palm oil led to excess lipid accumulation in the liver of large yellow croaker (Larimichthys crocea), accompanied by significant induction of FABP1. In cultured cells, palmitic acid (PA), a kind of SFA, triggered the fabp1 expression and increased triglyceride (TG) contents. Knockdown of FABP1 dampened PA-induced TG accumulation through mitigated lipogenesis. The overexpression of FABP1 showed the opposite result. Furthermore, the inactivation of FABP1 led to induction in insulin-induced gene 1 (INSIG1) expression, which attenuated the processing of sterol regulatory element-binding protein 1 (SREBP1) by down-regulating the nuclear-localized SREBP1. These results revealed a previously unrecognized function of FABP1 in response to PA, providing additional evidence for targeting FABP1 in the treatment of NAFLD caused by SFA.
Assuntos
Proteínas de Ligação a Ácido Graxo , Hepatócitos , Lipogênese , Perciformes , Proteína de Ligação a Elemento Regulador de Esterol 1 , Animais , Hepatócitos/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Perciformes/metabolismo , Perciformes/genética , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Triglicerídeos/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Ácido Palmítico/farmacologia , Células CultivadasRESUMO
Chemokines are cytokines that mediate leukocyte traffic between the lymphoid organs, the bloodstream, and the site of tissue damage, which is essential for an efficient immune response. In particular, the gamma interferon (IFN- γ) inducible chemokines CXCL9, CXCL10, and CXCL11, and their receptor CXCR3, are involved in T cell and macrophage recruitment to the site of infection. The nature and function of these chemokines and their receptor are well-known in mammals, but further research is needed to achieve a similar level of understanding in fish immunity. Thus, in this study, we seek to identify the genes encoding the components of the Atlantic salmon (Salmo salar) CXCL9, CXCL10, CXCL11/CXCR3 axis (CXCL9-11/CXCR3), predict the protein structure from the amino acid sequence, and explore the regulation of gene expression as well as the response of these chemokines and their receptor to viral infections. The cxcl9, cxcl10, cxcl11, and cxcr3 gene sequences were retrieved from the databases, and the phylogenetic analysis was conducted to determine the evolutionary relationships. The study revealed an interesting pattern of clustering and conservation among fish and mammalian species. The salmon chemokine sequences clustered with orthologs from other fish species, while the mammalian sequences formed separate clades. This indicates a divergent evolution of chemokines between mammals and fish, possibly due to different evolutionary pressures. While the structural analysis of the chemokines and the CXCR3 receptor showed the conservation of critical motifs and domains, suggesting preserved functions and stability throughout evolution. Regarding the regulation of gene expression, some components of the CXCL9-11/CXCR3 axis are induced by recombinant gamma interferon (rIFN-γ) and by Infectious pancreatic necrosis virus (IPNV) infection in Atlantic salmon cells. Further studies are needed to explore the role of Atlantic salmon CXCL9-11 chemokines in regulating immune cell migration and endothelial activation, as seen in mammals. To the best of our knowledge, there have been no functional studies of chemokines to understand these effects in Atlantic salmon.
Assuntos
Quimiocina CXCL9 , Filogenia , Receptores CXCR3 , Salmo salar , Animais , Salmo salar/imunologia , Salmo salar/genética , Receptores CXCR3/genética , Receptores CXCR3/metabolismo , Quimiocina CXCL9/genética , Quimiocina CXCL9/metabolismo , Quimiocina CXCL9/imunologia , Regulação da Expressão Gênica , Quimiocina CXCL11/genética , Quimiocina CXCL11/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Proteínas de Peixes/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Vírus da Necrose Pancreática Infecciosa/imunologiaRESUMO
Protein glutaminases (PG; EC = 3.5.1.44) are enzymes known for enhancing protein functionality. In this study, we cloned and expressed the gene chryb3 encoding protein glutaminase PG3, exhibiting 39.4 U/mg specific activity. Mature-PG3 featured a substrate channel surrounded by aromatic and hydrophobic amino acids at positions 38-45 and 78-84, with Val81 playing a pivotal role in substrate affinity. The dynamic opening and closing motions between Gly65, Thr66, and Cys164 at the catalytic cleft greatly influence substrate binding and product release. Redesigning catalytic pocket and cocatalytic region produced combinatorial mutant MT6 showing a 2.69-fold increase in specific activity and a 2.99-fold increase at t65 °C1/2. Furthermore, MT6 boosted fish myofibrillar protein (MP) solubility without NaCl. Key residues such as Thr3, Asn54, Val81, Tyr82, Asn107, and Ser108 were vital for PG3-myosin interaction, particularly Asn54 and Asn107. This study sheds light on the catalytic mechanism of PG3 and guided its rational engineering and utilization in low-salt fish MP product production.
Assuntos
Proteínas de Peixes , Glutaminase , Miofibrilas , Engenharia de Proteínas , Glutaminase/metabolismo , Glutaminase/genética , Glutaminase/química , Animais , Proteínas de Peixes/genética , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Miofibrilas/química , Miofibrilas/metabolismo , Miofibrilas/genética , Proteínas Musculares/genética , Proteínas Musculares/química , Proteínas Musculares/metabolismo , CinéticaRESUMO
Metabotropic glutamate receptor 4 (mGluR4) is widely regarded as an umami receptor activated by L-glutamate to exert essential functions. Numerous studies have shown that umami receptors participate in food intake regulation. However, little is known about mGluR4's role in mediating food ingestion and its possible molecular mechanism. Mandarin fish, a typical carnivorous fish, is sensitive to umami substances and is a promising vertebrate model organism for studying the umami receptor. In this study, we identified the mGluR4 gene and conducted evolutionary analyses from diverse fish species with different feeding habits. mGluR4 of mandarin fish was cloned and functionally expressed to investigate the effects of L-glutamate on mGluR4. We further explored whether the signal pathway mGluR4-Ca2+-ERK1/2 participates in the process in mandarin fish brain cells. The results suggest that L-glutamate could regulate Neuropeptide Y (Npy) via the mGluR4-Ca2+-ERK1/2 signaling pathway in mandarin fish. Our findings unveil the role of mGluR4 in feeding decisions and its possible molecular mechanisms in carnivorous fishes.
Assuntos
Proteínas de Peixes , Ácido Glutâmico , Sistema de Sinalização das MAP Quinases , Neuropeptídeo Y , Receptores de Glutamato Metabotrópico , Animais , Sequência de Aminoácidos , Cálcio/metabolismo , Proteínas de Peixes/metabolismo , Proteínas de Peixes/genética , Peixes/metabolismo , Peixes/genética , Ácido Glutâmico/metabolismo , Neuropeptídeo Y/metabolismo , Neuropeptídeo Y/genética , Perciformes/metabolismo , Perciformes/genética , Filogenia , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/genéticaRESUMO
The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life's evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5'ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5'ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5'ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.
Before the immune system can eliminate a bacterium, virus or other type of pathogen, it needs to be able to recognize these foreign elements. To achieve this, cells in the immune system have proteins called pattern recognition receptors (PRRs) which can identify distinct molecular features of certain pathogens. One specific group of PRRs is a family of retinoic acid-induced RIG-I-like receptors (RLRs), which help immune cells detect different types of viruses. Members of this family recognize distinct motifs on the genetic material of viruses known as RNA. For instance, RIG-I recognizes a marker known as 5'ppp on the end of single-stranded RNA molecules, whereas MDA5 recognizes long strands of double-stranded RNA. Many vertebrates including various mammals, birds, and fish lost the RIG-I receptor over the course of evolution. However, Geng et al. predicted that some animals lacking the RIG-I receptor may still be able to activate an immune response against viruses that contain the 5'ppp-RNA motif. To investigate this possibility, Geng et al. studied chickens and miiuy croakers (a type of ray-finned fish) which no longer have a RIG-I receptor. They found that both animals can still sense and eliminate two 5'ppp-RNA viruses called VSV and SCRV. Further experiments revealed that these two viruses are detected by a modified MDA5 receptor that had evolved to bind to 5'-ppp and activate the antiviral response. Viruses are also continuously evolving new ways to escape the immune system. This led Geng et al. to investigate whether SCRV, which causes serious harm to marine fish, has evolved a way to evade the MDA5 protection mechanism. Using miiuy croakers as a model, they found that SCRV causes the transcripts that produce the MDA5 protein to contain more molecules of m6a. This molecular tag degrades the transcript, leading to lower levels of MDA5, reducing the antiviral response against SCRV. The findings of Geng et al. offer valuable perspectives on how the immune system adapts over the course of evolution, and highlight the diversity of antiviral responses in vertebrates. Chickens and miiuy croakers are commonly farmed animals, and further work investigating how viruses invade these species could prevent illnesses from spreading and having a negative impact on the economy.
Assuntos
Proteína DEAD-box 58 , Helicase IFIH1 Induzida por Interferon , Animais , Helicase IFIH1 Induzida por Interferon/metabolismo , Helicase IFIH1 Induzida por Interferon/genética , Proteína DEAD-box 58/metabolismo , Proteína DEAD-box 58/genética , Peixes/virologia , Peixes/genética , Peixes/imunologia , Vírus de RNA/genética , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Evolução MolecularRESUMO
This study aimed to investigate the effect of oxidation on fish gelatin and its emulsifying properties. Fish gelatin was oxidized with varying concentrations of H2O2 (0-30 mM). Increased concentrations of the oxidant led to a decrease in amino acids in the gelatin, including glycine, lysine, and arginine. Additionally, the relative content of ordered secondary structure and triple helix fractions decreased. Zeta potential decreased, while particle size, surface hydrophobicity, and water contact angle increased. Regarding emulsifying behavior, oxidation promoted the adsorption of gelatin to the oil-water interface and reduced interfacial tension. With increased degrees of oxidation, the zeta potential and size of the emulsion droplets decreased. The oxidized gelatin exhibited better emulsifying activity but worse emulsifying stability. Based on these results, a mechanism for how oxidation affects the emulsifying properties of gelatin was proposed: the increase in gelatin's hydrophobicity and the decrease in triple helix structure induced by oxidation reduced the interfacial tension at the oil-water interface. This promoted protein adsorption at the oil-water interface, allowing the formation of smaller oil droplets and enhancing gelatin's emulsifying activity. However, the decrease in electrostatic repulsion between emulsion droplets and the decrease in solution viscosity increased the flocculation and aggregation of oil droplets, ultimately weakening the emulsifying stability of gelatin.
Assuntos
Emulsões , Proteínas de Peixes , Gelatina , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Gelatina/química , Emulsões/química , Animais , Proteínas de Peixes/química , Tamanho da Partícula , Peróxido de Hidrogênio/química , Viscosidade , Aminoácidos/química , Tensão Superficial , Emulsificantes/química , Peixes , Adsorção , Estrutura Secundária de ProteínaRESUMO
Fish sex is largely influenced by steroid hormones, especially sex hormones. Here, we established a steroid hormone-free genetic model by mutation of cyp11a1 in Nile tilapia, which was confirmed by EIA assay. Gonadal phenotype and transcriptome analyses showed that the XX mutants displayed sex reversal from female to male but with defective spermatogenesis. Despite the sex reversal, the aromatase encoding gene cyp19a1a was continuously expressed in the gonads of the XX mutants, which might be caused by androgen deficiency. Whole-mount fluorescence in situ hybridization and transcriptome analysis showed that the gonads of the XX mutants firstly developed towards ovary but shifted to testis between 10 to 15 days after hatching. Detailed expression analysis of key sex differentiation pathway genes foxl3 and dmrt1 combined with apoptosis analysis revealed transdifferentiation of germ cells from female to male during sex reversal. Rescue experiments showed that both P5 and E2 treatment rescued the sex reversal of cyp11a1 mutant XX fish. Overall, our results revealed a transient ovary-like stage and transdifferentiation of germ cells from female to male in the early gonads of the steroid hormone-deprived cyp11a1 mutant XX fish.
Assuntos
Mutação , Ovário , Diferenciação Sexual , Animais , Feminino , Ovário/metabolismo , Masculino , Diferenciação Sexual/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Ciclídeos/genética , Ciclídeos/metabolismo , Transtornos do Desenvolvimento Sexual/genética , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Tilápia/genética , Tilápia/metabolismo , Processos de Determinação Sexual/genéticaRESUMO
Fish are exposed to increased water temperatures and aquatic pollutants, including endocrine-disrupting compounds (EDCs). Although each stressor can disturb fish liver metabolism independently, combined effects may exist. To unveil the molecular mechanisms behind the effects of EDCs and temperature, fish liver cell lines are potential models needing better characterisation. Accordingly, we exposed the rainbow trout RTL-W1 cells (72 h), at 18 °C and 21 °C, to ethynylestradiol (EE2), levonorgestrel (LNG), and a mixture of both hormones (MIX) at 10 µM. The gene expression of a selection of targets related to detoxification (CYP1A, CYP3A27, GST, UGT, CAT, and MRP2), estrogen exposure (ERα, VtgA), lipid metabolism (FAS, FABP1, FATP1), and temperature stress (HSP70b) was analysed by RT-qPCR. GST expression was higher after LNG exposure at 21 °C than at 18 °C. LNG further enhanced the expression of CAT, while both LNG and MIX increased the expressions of CYP3A27 and MRP2. In contrast, FAS expression only increased in MIX, compared to the control. ERα, VtgA, UGT, CYP1A, HSP70b, FABP1, and FATP1 expressions were not influenced by the temperature or the tested EDCs. The RTL-W1 model was unresponsive to EE2 alone, sensitive to LNG (in detoxification pathway genes), and mainly insensitive to the temperature range but had the potential to unveil specific interactions.
Assuntos
Etinilestradiol , Levanogestrel , Oncorhynchus mykiss , Animais , Etinilestradiol/toxicidade , Levanogestrel/farmacologia , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/metabolismo , Estrogênios/metabolismo , Linhagem Celular , Disruptores Endócrinos/toxicidade , Inativação Metabólica/genética , Regulação para Cima/efeitos dos fármacos , Progestinas/farmacologia , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Poluentes Químicos da Água/toxicidade , Temperatura , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genéticaRESUMO
The smoltification of farmed Atlantic salmon is commonly associated with mild immunosuppression. However, B cells may deviate from this trend, showing increased proliferation and migration during this period. This study assessed the effects of smoltification and adaptation to seawater in a controlled experiment. Analyses were conducted on the head kidney, spleen, gill, and both visceral and subcutaneous fat (VAT, SAT) across four time points: parr, early and complete smoltification, and twelve weeks post-seawater transfer. Gene expression analysis was performed to track the distribution and developmental changes in their B cells. Expression profiles of three types of immunoglobulins (ig), including membrane-bound and secreted forms of igm, as well as B cell-specific markers pax1 and cd79, showed strong correlations and contrasted with profiles of other immune cell markers. The highest levels of expression were observed in the lymphatic tissue, followed by the VAT. Enhanced expression in the gill and adipose tissues of smolts suggested an increase in B cell populations. Parallel sequencing of the variable region of the IgM heavy chain was used to track B cell traffic, assessed by the co-occurrence of the most abundant sequences (clonotypes) across different tissues. Smoltification markedly enhanced traffic between all tissues, which returned to initial levels after twelve weeks in the sea. The preferred migration between the head kidney, spleen, and VAT supports the role of abdominal fat as a reservoir of lymphocytes. These findings are discussed in the context of recent studies that suggested the functional significance of B cell traffic in Atlantic salmon. Specifically, the migration of B cells expressing secreted immunoglobulins to virus-infected hearts has been identified as a key factor in the disease recovery and survival of fish challenged with salmon alphavirus (SAV); this process is accelerated by vaccination. Additionally, the study of melanized foci in the skeletal muscles revealed an association between antigen-dependent differentiation and the migration of B cells, indicating a transfer from local to systemic immune responses. Updating the antibody repertoire in the lymphatic and peripheral tissues of smolts may assist in their adaptation to the marine environment and in encountering new pathogens. Emerging evidence highlights B cell migration as an important and previously unrecognized immune mechanism in salmonids.
Assuntos
Linfócitos B , Salmo salar , Animais , Salmo salar/genética , Salmo salar/imunologia , Salmo salar/crescimento & desenvolvimento , Linfócitos B/imunologia , Linfócitos B/metabolismo , Água do Mar , Baço/imunologia , Baço/metabolismo , Baço/citologia , Brânquias/metabolismo , Brânquias/citologia , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Imunoglobulina M/genéticaRESUMO
Background: Toll-like receptor (TLR), as an important pattern recognition receptor, is a bridge between non-specific immunity and specific immunity, and plays a vital role in the disease resistance of aquatic animals. However, the function of TLR in Pelodiscus sinensis is still unclear. Methods and Results: The sequence characteristics and homology of three TLRs (PsTLR2, PsTLR3 and PsTLR5) were determined in this investigation. Their annotation and orthologies were supported by phylogenetic analysis, functional domain prediction, and sequence similarity analysis. qPCR showed that the identified TLRs were expressed in all tissues, among the high expression of PsTLR5 in the brain and liver and the high expression of PsTLR2 and PsTLR3 in the liver. PsTLR2 mRNA expression increased 6.7-fold in the liver 12 h after Aeromonas hydrophila infection, while the mRNA expression of PsTLR3 was down-regulated by 0.29 times in liver and 0.31 times in spleen. The mRNA expression of PsTLR5 was significantly up-regulated in four immune tissues, and it was up-regulated by 122.8 times in the spleen after 72 h infection. Finally, the recombinant proteins of extracellular LRR domains of these three TLRs were obtained by prokaryotic expression technology, and the binding tests were performed to discover their ability of binding pathogenic microorganisms. Microbial binding test showed that rPsTLR2, rPsTLR3 and rPsTLR5 can combine A. hydrophila, Edwardsiella tarda, Vibrio parahaemolyticus, Staphylococcus aureus, Streptococcus agalactiae and Candida albicans, while rPsTLR3 can bind A. hydrophila, E. tarda, V. parahaemolyticus and C. albicans. Conclusions: Our findings suggested that TLRs may be crucial to turtles' innate immune response against microbes.
Assuntos
Aeromonas hydrophila , Infecções por Bactérias Gram-Negativas , Receptores Toll-Like , Animais , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/veterinária , Tartarugas/microbiologia , Tartarugas/genética , Tartarugas/imunologia , Filogenia , Imunidade Inata/genética , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Proteínas de Peixes/metabolismo , Doenças dos Peixes/microbiologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/genéticaRESUMO
17α-Methyltestosterone (MT) is a widely used androgen for all-male fish production in aquaculture. However, the molecular mechanism underlying MT-induced masculinization remains unclear. In this study, we aim to identify the key gene responsible for MT-induced masculinization using the Nile tilapia (Oreochromis niloticus) amhy, dmrt1, and gsdf mutants, which exhibit male-to-female sex reversal. Nile tilapia fry from these three mutant lines were treated with 50 µg/g MT from 5 to 30 days after hatching (dah). The results showed that amhy and gsdf mutants, but not dmrt1 mutants, were masculinized by the MT treatment. Gonadal transcriptome analysis revealed that genes involved in steroidogenesis and germ cell development in MT-treated dmrt1 mutants exhibited a similar expression pattern to that of the wild type (WT) XX. In addition, the dmrt1 mutants cannot be masculinized by co-treatment with MT and the aromatase inhibitor fadrozole. The MT treatment completely blocked early steroidogenic enzyme (Star2, Cyp17a2, and Cyp19a1a) expression independent of amhy, gsdf, and dmrt1. A luciferase analysis showed that MT directly suppressed basal and Sf-1-activated cyp19a1a promoter activity through ara and arb in cultured HEK293 cells. Furthermore, MT treatment inhibited germ cell proliferation in amhy and gsdf mutants but not in dmrt1 mutants. Consistently, dmrt1 expression was induced in MT-treated WT XX, -amhy, and -gsdf mutants. Taken together, these results suggest that dmrt1 is indispensable for MT-induced masculinization in Nile tilapia and that MT functions by inhibiting early steroid synthesis and activating dmrt1 to promote testis development.
Assuntos
Androgênios , Ciclídeos , Metiltestosterona , Fatores de Transcrição , Animais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Masculino , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Androgênios/metabolismo , Androgênios/farmacologia , Metiltestosterona/farmacologia , Feminino , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Diferenciação Sexual/genética , Mutação , Humanos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacosRESUMO
The marine environment is an excellent source for many physiologically active compounds due to its extensive biodiversity. Among these, fish proteins stand out for their unique qualities, making them valuable in a variety of applications due to their diverse compositional and functional properties. Utilizing fish and fish coproducts for the production of protein hydrolysates and bioactive peptides not only enhances their economic value but also reduces their potential environmental harm, if left unutilized. Fish protein hydrolysates (FPHs), known for their excellent nutritional value, favorable amino acid profiles, and beneficial biological activities, have generated significant interest for their potential health benefits. These hydrolysates contain bioactive peptides which are peptide sequences known for their beneficial physiological effects. These biologically active peptides play a role in metabolic regulation/modulation and are increasingly seen as promising ingredients in functional foods, nutraceuticals and pharmaceuticals, with potential to improve human health and prevent disease. This review aims to summarize the current in vitro, cell model (in situ) and in vivo research on the antioxidant, glycaemic management and muscle health enhancement properties of FPHs and their peptides.
Assuntos
Antioxidantes , Proteínas de Peixes , Peixes , Proteínas Musculares , Peptídeos , Hidrolisados de Proteína , Hidrolisados de Proteína/química , Animais , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Antioxidantes/química , Antioxidantes/farmacologia , Humanos , Peptídeos/química , Peptídeos/farmacologia , Proteínas Musculares/química , Proteínas Musculares/metabolismo , Glucose/metabolismo , Glucose/químicaRESUMO
ß-Enolase is a cross-allergen commonly found in fungi, plants, and aquatic products. Although studies on the allergenicity of fish enolase have been reported in recent years, they are still limited to a few species of marine fish. Therefore, the detection of freshwater fish in the food industry requires more studies of the molecular characterization as well as the allergenicity of enolase. In this study, the nucleotide sequence of ß-enolase from grass carp was obtained by molecular cloning technology. Structural domain analysis showed that it contained the characteristic structural domains of the enolase superfamily, and homology analysis indicated that enolases are highly conserved evolutionarily. Recombinant ß-enolase was obtained by prokaryotic expression, and its allergenicity was assessed by ß-enolase-sensitized mice, which confirmed the ability of ß-enolase to trigger an allergic response and cause a rise in Th1 and Th2 immune responses in mice. These results suggest that ß-enolase could be used as a characterizing substance for the detection of fish allergens in the food industry as well as the preparation of drugs for allergy-related studies.
Assuntos
Alérgenos , Carpas , Clonagem Molecular , Proteínas de Peixes , Fosfopiruvato Hidratase , Animais , Carpas/imunologia , Carpas/genética , Fosfopiruvato Hidratase/imunologia , Fosfopiruvato Hidratase/genética , Fosfopiruvato Hidratase/química , Alérgenos/imunologia , Alérgenos/genética , Alérgenos/química , Camundongos , Proteínas de Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/química , Camundongos Endogâmicos BALB C , Feminino , Sequência de Aminoácidos , Expressão Gênica , Humanos , Hipersensibilidade Alimentar/imunologia , Alinhamento de SequênciaRESUMO
The original UT-1 transporter gene was initially identified in the spiny dogfish (Squalus acanthias), but localization of the UT-1 protein was not determined. Subsequent UT-1 expression was shown to localize to the collecting tubule (CT) of the shark nephron in other shark species, with expression in a closely related chimaera species also located additionally at a lower level in the intermediate-I segment (IS-I) of the nephron. In spiny dogfish, two UT-1 splice variants are known (UT-1 long and short), and there was also a second UT-1 gene described (here termed Brain UT). In this study, a second splice variant of the second Brain UT gene was discovered. Expression profiles (mRNA) of UT-1 long and short and Brain UT were determined in a number of spiny dogfish tissues. Quantitative PCR in kidney samples showed that the level of the short variant of UT-1 was around 100 times higher than the long variant, which was itself expressed around 10 times higher than Brain UT cDNA/mRNA (in kidney). For the long variant, there was a significantly higher level of mRNA abundance in fish acclimatized to 75% seawater. Ultimately, three UT-1 antibodies were made that could bind to both the UT-1 short and long variant proteins. The first two of these showed bands of appropriate sizes on Western blots of around 52.5 and 46 kDa. The second antibody had some additional lower molecular weight bands. The third antibody was mainly bound to the 46 kDa band with faint 52.5 kDa staining. Both the 52.5 and 46 kDa bands were absent when the antibodies were pre-blocked with the peptide antigens used to make them. Across the three antibodies, there were many similarities in localization but differences in subcellular localization. Predominantly, antibody staining was greatest in the intermediate segment 1 (IS-I) and proximal (PIb) segments of the first sinus zone loop of the nephron, with reasonably strong expression also found at the start and middle of the late distal tubule (LDT; second sinus zone loop). While some expression in the collecting tubule (CT) could not be ruled out, the level of staining seemed to be low or non-existent in convoluted bundle zone nephron segments such as the CT. Hence, this suggests that spiny dogfish have a fundamentally different mode of urea absorption in comparison to that found in other shark species, potentially focused more on the nephron sinus zone loops than the CT.
Assuntos
Proteínas de Membrana Transportadoras , Squalus acanthias , Animais , Squalus acanthias/metabolismo , Squalus acanthias/genética , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/genética , Tubarões/metabolismo , Tubarões/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Transportadores de Ureia , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Sequência de Aminoácidos , Encéfalo/metabolismoRESUMO
Background/Objectives: Stearoyl-coenzyme A desaturase 1 (SCD1) plays a crucial role in fatty acid metabolism. However, its roles in the feeding habit transformation of mandarin fish (Siniperca chuatsi) remain largely unknown. Methods: Juvenile mandarin fish (10.37 ± 0.54)g were trained to feed on an artificial diet and then divided into artificial diet feeders and nonfeeders according to their feed preference. Afterwards, the scd1 gene of mandarin fish (Sc-scd1) was identified and characterized, and its transcription difference was determined between S. chuatsi fed live artificial diets and those fed prey fish. Results: Our results show that Sc-scd1 coding sequence is 1002 bp long, encoding 333 amino acids. The assumed Sc-SCD1 protein lacks a signal peptide, and it contains 1 N-linked glycosylation site, 24 phosphorylation sites, 4 transmembrane structures, and 3 conserved histidine elements. We found that Sc-SCD1 exhibits a high similarity with its counterparts in other fish by multiple alignments and phylogenetic analysis. The expression level of Sc-scd1 was detected with different expression levels in all tested tissues between male and female individuals fed either live prey fish or artificial diets. Conclusions: In particular, the Sc-scd1 expression level was the highest in the liver of both male and female mandarin fish fed artificial diets, indicating that scd1 genes may be associated with feed adaption of mandarin fish. Taken together, our findings offer novel perspectives on the potential roles of scd1 in specific domestication, and they provide valuable genetic information on feeding habits for the domestication of mandarin fish.
Assuntos
Clonagem Molecular , Proteínas de Peixes , Estearoil-CoA Dessaturase , Animais , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Feminino , Masculino , Dieta/veterinária , Ração Animal , Filogenia , Perciformes/genética , Perciformes/metabolismo , Comportamento AlimentarRESUMO
Nanog is a crucial regulatory factor in maintaining the self-renewal and pluripotency of embryonic stem cells. It is involved in various biological processes, such as early embryonic development, cell reprogramming, cell cycle regulation, the proliferation and migration of primordial germ cells. While research on this gene has primarily focused on mammals, there has been a growing interest in studying nanog in fish. However, there is a notable lack of comprehensive reviews regarding this gene in fish, which is essential for guiding future research. This review aims to provide a thorough summary of the gene's structure, expression patterns, functions and regulatory mechanisms in fish. The findings suggest that nanog probably has both conserved and divergent functions in regulating cell pluripotency, early embryonic development, and germ cell development in teleosts compared to other species, including mammals. These insights lay the foundation for future research and applications of the nanog gene, providing a new perspective for understanding the evolution and conserved charactristics of teleost nanog.