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As most teleosts are unable to synthesize vitamin C, supplemental diets containing vitamin C diets play a crucial role in fish health. The aim of this study was to investigate the effect of dietary vitamin C on the intestinal enzyme activity and intestinal microbiota of silver pomfre (Pampus argenteus). Four experimental diets were supplemented with basic diets containing 300 mg of vitamin C/kg (group tjl3), 600 mg of vitamin C/kg (group tjl6), and 1200 mg of vitamin C/kg (group tjl12), as well as vitamin C-free supplemental basic diet (group tjl0), respectively. The four diets were fed to juvenile P. argenteus (average initial weight: 4.68 ± 0.93 g) for 6 weeks. The results showed that the activity of SOD (superoxide dismutase) and CAT (catalase) increased significantly while that of MDA (malondialdehyde) decreased significantly in group tjl3 compared to vitamin group tjl0. At the genus level, groups tjl0, tjl6, and tjl12 contained the same dominant microbial community, Stenotrophomonas, Photobacterium, and Vibrio, whereas group tjl3 was dominated by Stenotrophomonas, Delftia, and Bacteroides. Among the fish fed with a basic diet containing 300 mg of vitamin C/kg, the intestines exhibited a notable abundance of probiotic bacteria, including lactic acid bacteria (Lactobacillus) and Bacillus. The abundance of Aeromonas in groups tjl3 and tjl6 was lower than that of the vitamin C-free supplemental basic diet group, whereas Aeromonas was not detected in group tjl12. In addition, a causative agent of the disease outbreak in cultured P. argenteus, Photobacterium damselae subsp. Damselae (PDD) was the dominant microbiota community in groups tjl0, tjl6 and tjl12, whereas the abundance of PDD in group tjl3 was the lowest among the diets. Taken together, the diets supplied with vitamin C could influence the composition microbial community of P. argenteus. The low level of vitamin C (300 mg of vitamin C/kg per basic diet) supplementation could not only improve the antioxidant capacity but also resist the invasion of pathogenic bacteria.
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Antioxidantes , Ácido Ascórbico , Suplementos Dietéticos , Microbioma Gastrointestinal , Animales , Ácido Ascórbico/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Antioxidantes/farmacología , Antioxidantes/metabolismo , Perciformes/microbiología , Alimentación Animal/análisis , Superóxido Dismutasa/metabolismo , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Dieta/veterinaria , Catalasa/metabolismoRESUMEN
The complement system is pivotal in innate immune defense, with Complement 1qb (C1qb) playing a key role in recognizing immune complexes and initiating the classical pathway. In this research, we cloned the full-length cDNA of silver pomfret (Pampus argenteus) c1qb and demonstrated its role in mediating defense responses against Nocardia seriolae (N. seriolae) infection, which notably causes significant economic losses in the aquaculture industry. Our investigation revealed that N. seriolae infection led to tissue damage in fish bodies, as observed in tissue sections. Subsequent analysis of differential genes (DEGs) in the transcriptome highlighted genes linked to apoptosis and inflammation. Through experiments involving overexpression and interference of c1qb in vitro, we confirmed that c1qb could suppress N. seriolae-induced apoptosis and inflammation. Moreover, overexpression of c1qb hindered N. seriolae invasion, and the purified and replicated C1qb protein displayed antimicrobial properties. Additionally, our study unveiled that overexpression of c1qb might stimulate the expression of membrane attack complexes (MAC), potentially enhancing opsonization and antibacterial effects. In conclusion, our findings offer valuable insights into the immune antibacterial mechanisms of c1qb and contribute to the development of strategies for controlling N. seriolae.
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Apoptosis , Complemento C1q , Complejo de Ataque a Membrana del Sistema Complemento , Inflamación , Nocardia , Complemento C1q/metabolismo , Complemento C1q/genética , Apoptosis/genética , Animales , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Inflamación/genética , Inflamación/metabolismo , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/microbiología , Nocardiosis/inmunología , Nocardiosis/microbiología , Nocardiosis/metabolismo , Nocardiosis/genéticaRESUMEN
Members of the Signal Transducer and Activator of Transcription (STAT) family function pivotally as transcriptional activators integral to the modulation of inflammatory responses. The aquaculture of silver pomfret is frequently compromised by the imposition of exogenous stressors, which include thermal fluctuations, notably low-temperatures, diminished oxygen levels, and the onslaught of bacterial pathogens. Notwithstanding the critical impact of these stressors, the scientific literature presents a notable gap in our understanding of the STAT pathway's role in the silver pomfret's adaptive response mechanisms. To address this lacuna, we identified stat genes in the silver pomfret-denominated as Pastat1, Pastat2, Pastat3, Pastat4, and Pastat5-through a thorough and systematic bioinformatics analysis. Further scrutiny of the gene configurations and constituent motifs has elucidated that STAT proteins possess analogous structural frameworks and exhibit significant evolutionary preservation. Subsequently, the expression patterns of five stat genes were verified by RT-qPCR in twelve different tissues and four growth periods in healthy fish, showing that the expression of Pastat genes was temporally and spatially specific, with most of the stat genes expressed at higher levels in the spleen, following muscle, gill, and liver. Transcriptomic analysis of exposure to exogenous stressors, specifically formaldehyde and low-temperature conditions, elucidated that Pastat1 and Pastat2 genes exhibited a heightened sensitivity to these environmental challenges. RT-qPCR assays demonstrated a marked alteration in the expression profiles of jak1 and Pastat gene suites in PaS upon prolonged bacterial infection subsequent to these exogenous insults. Moreover, the gene expression of the downstream effectors involved in innate immunity and apoptosis displayed marked deviations. This study additionally elucidated the Pastat gene family's role in modulating the innate immune response and apoptotic regulation within the silver pomfret during exogenous stressors and subsequent pathogenic incursions.
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Enfermedades de los Peces , Proteínas de Peces , Inmunidad Innata , Perciformes , Factores de Transcripción STAT , Estrés Fisiológico , Animales , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Proteínas de Peces/química , Enfermedades de los Peces/inmunología , Perciformes/inmunología , Perciformes/genética , Inmunidad Innata/genética , Factores de Transcripción STAT/genética , Factores de Transcripción STAT/metabolismo , Regulación de la Expresión Génica/inmunología , Regulación de la Expresión Génica/efectos de los fármacos , Perfilación de la Expresión Génica/veterinaria , Filogenia , Alineación de Secuencia/veterinaria , Vibriosis/inmunología , Vibriosis/veterinaria , Secuencia de AminoácidosRESUMEN
Pampus is a widespread species of fish in the western Pacific and Indian Oceans that has significant commercial worth. Its evolutionary history and phylogenetics are still poorly understood, and details on its intraspecific taxonomy are debatable, despite some morphological and molecular research. Here, we analyzed this species using skeletal structure data as well as nuclear (S7 gene) and mitochondrial genetic information (COI, D-loop and mitogenomes). We found that the genetic distance between P. argenteus and P. echinogaster was much smaller than that between other Pampus species, and both maximum likelihood and Bayesian phylogenetic trees yielded almost identical tree topologies. An additional and adjacent M repeat was found in the downstream region of the IQM gene cluster of P. argenteus and P. echinogaster, and the trnL2 gene of P. minor was translocated. The genus Pampus experienced early rapid radiation during the Palaeocene with major lineages diversifying within a relatively narrow timescale. Additionally, three different methods were conducted to distinguish the genus Pampus species, proving that P. argenteus and P. echinogaster are the same species, and P. liuorum is speculated to be a valid species. Overall, our study provides new insights not only into the evolutionary history of Pampus but its intraspecific taxonomy as well.
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As indicator organisms for water pollution detection, Pseudogasteromyzon species play a vital role in aquatic environment monitoring. We have successfully sequenced the mitogenomes of P. fasciatus jiulongjiangensis and P. myersi and downloaded the mitogenomes of nine other Pseudogastromyzon fish on GenBank to conduct a detailed comparative analysis of their phylogenetic relationships and evolutionary history. The findings revealed a conservation in both gene composition and gene order. Except for the trnS1 gene lacking dihydrouracil arms, the other 21 tRNAs showed the typical clover-leaf secondary structure. According to the ΔRSCU method, we identified the seven most abundant optimal codons: CUA, GUA, CCA, CAA, GAA, AGC, and GGC. The construction of maximum parsimony, maximum likelihood, and Bayes trees yielded congruent topologies, and the 11 Pseudogastromyzon species were clustered into two major clusters. Among them, one of which was composed of P. fangi, P. changtingensis changtingensis, and P. changtingensis tungpeiensis, while the remaining eight species formed another cluster, further subdivided into five smaller clusters. Distinct clusters formed between P. fasciatus jiulongjiangensis and P. meihuashanensis, P. cheni and P. peristictus, and P. laticeps and P. lianjiangensis, and the remaining two species were clustered separately, thereby enhancing our understanding of them. Furthermore, our analysis results of divergence times revealed that these 11 Pseudogasteromyzon species underwent rapid differentiation in the Pleistocene epochs. Overall, our study sheds light on the phylogenetic relationship and evolutionary history of Pseudogasteromyzon species, providing a necessary knowledge foundation for further understanding the intricacies of an ecosystem health assessment.
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In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development.
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Perciformes , Receptores de Estrógenos , Animales , Masculino , Femenino , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Aromatasa/metabolismo , Semen/metabolismo , Ovario/metabolismo , Estrógenos/metabolismo , Peces/metabolismo , Perciformes/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismoRESUMEN
Compensatory growth (CG) in fish is heavily influenced by nutrient metabolism. However, there are limited studies examining how nutrient metabolism is regulated during this process. For silver pomfret, an important commercial marine fish, it's crucial to establish effective starvation and re-feeding strategies to ensure good water quality and fast growth. To identify the complete compensatory growth model of silver pomfret, we conducted an experiment with a control group (normal feeding) and three starvation/re-feeding groups. We observed that the recovery of weight and condition factor in the 14-day starvation and 14-day re-feeding groups was significantly faster than other groups, indicating full compensatory growth. Thus, we selected this group for the next experiment. We performed untargeted metabolomics and transcriptome analysis of muscle tissue on Day 14, 21 and 28 (CG process), and examined the key regulatory genes of nutrient metabolism on Day 0, 7, 14, 21 and 28 (starvation and re-feeding process). Our data revealed that during starvation, silver pomfret first utilized carbohydrates and short-chain lipids, followed by proteins and long-chain lipids. After re-feeding, lipids accumulated first, resulting in rapid growth, followed by the recovery of protein content in muscle. During starvation, the expression of anabolic-related genes such as TER and CALR decreased, and catabolic-related genes such as TSC2 and MLYCD increased, promoting the AMPK pathway. During re-feeding, anabolic-related gene expression increased without AMPK inhibition. Our findings provide insights into the energy utilization strategies of fish and molecular regulation during compensatory growth in fish.
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Proteínas Quinasas Activadas por AMP , Perfilación de la Expresión Génica , Animales , Músculos , LípidosRESUMEN
Toll-like receptors (TLRs) are vital pattern recognition receptors that play a critical role in the innate immune response against pathogenic attack. Among the bacteria commonly found in the culture process of silver pomfret, Photobacterium damselae subsp. Damselae (PDD, gram-negative) and Nocardia seriolae (NS, gram-positive), can cause large-scale mortality in this fish species. However, there is currently no research on the role of TLRs in mediating the immune response of silver pomfret to these two bacterial infections. Therefore, in this study, we identified nine PaTLRs family members, including several fish-specific TLRs (TLR14 and TLR21). Phylogenetic analysis revealed that these PaTLRs genes could be classified into five subfamilies, namely TLR1, TLR3, TLR5, TLR7, and TLR11, indicating their evolutionary conservation. To further explore the interactions of TLR genes with immune-related mediators, protein and protein interaction network (PPI) results were generated to explain the association of TLR genes with TNF receptor-associated factor 6 (TRAF6) and other relevant genes in the MyD88-dependent pathway and NF-κb signaling pathway. Subsequently, RT-qPCR was conducted to verify the expression patterns of the nine TLR genes in the gills, skin, kidney, liver, and spleen of healthy fish, with most of the TLRs showing high expression levels in the spleen. Following infection with PDD and NS, these PaTLRs exhibited different expression patterns in the spleen, with PaTLR2, PaTLR3, PaTLR5, PaTLR7, PaTLR9, and PaTLR14 being significantly up-regulated. Furthermore, when spleen cells were treated with bacterial compositions, the majority of PaTLRs expression was up-regulated in response to Lipopolysaccharide (LPS) and lipophosphorylcholic acid (LTA) treatment, except for PaTLR21. Finally, changes in the expression levels of TLR-interacting genes were also observed under the stimulation of bacteria and bacterial compositions. The results of this study provide a preliminary reference for further understanding the mechanism of the innate immune response of the TLR gene family in silver pomfret and offer theoretical support for addressing the disease problems encountered during large-scale fish breeding.
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Enfermedades de los Peces , Perciformes , Animales , Filogenia , Receptores Toll-Like , Photobacterium , Inmunidad Innata/genéticaRESUMEN
We cultured silver pomfret for 20 days, decreasing water temperature from 18 to 8 â, and sampled muscle every 5 days. Muscle fiber degeneration and apoptosis began to increase at 13 â detected by HE and TUNEL staining. Further analysis of transcriptome revealed that several apoptosis-related pathways were highly enriched by differentially expressed genes (DEGs). We analyzed 10 DEGs from these pathways by RT-qPCR during the temperature-decreasing process. JNK1, PIDD, CytC, Casp 3, and GADD45 were up-regulated after 15 and 20 days, while DUSP3, JNK2, and PARP genes were down-regulated after 15 and 20 days. DUSP5 was up-regulated from 10 to 20 days, and C-JUN was up-regulated after 20 days. We analyzed apoptosis in PaM cells under different temperatures (26 â, 23 â, 20 â, 17 â, and 14 â). The cell viability significantly declined from 14 to 20 â; the TUNEL and IHC results showed that the apoptosis signal increased with the temperature dropping, especially in 17 â and 14 â; DUSP5, JNK1, CytC, C-JUN, Casp 3, and GADD45 were up-regulated at 17 â and 14 â, and PIDD was up-regulated at 20 â, 17 â, and 14 â. DUSP3 was up-regulated at 20 â but down-regulated at 17 â and 14 â, and PARP was down-regulated at 17 â and 14 â. JNK2 was up-regulated at 20 â but down-regulated at 17 â and 14 â. Our results suggest that DUSP could help inhibit apoptosis in the initial stage of cold stress, but low temperature could down-regulate it and up-regulate JNK-C-JUN, inducing apoptosis in a later stage. These data provide a basis for the study of the response mechanism of fish to cold.
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Sistema de Señalización de MAP Quinasas , Proteína Quinasa 8 Activada por Mitógenos , Animales , Proteína Quinasa 8 Activada por Mitógenos/genética , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Proteína Quinasa 9 Activada por Mitógenos/genética , Proteína Quinasa 9 Activada por Mitógenos/metabolismo , Proteína Quinasa 9 Activada por Mitógenos/farmacología , Fosforilación , Respuesta al Choque por Frío , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , ApoptosisRESUMEN
Fish cell lines have become a useful tool to study in resource conservation, genetic breeding, diseases control, and environmental pollutants detection. The silver pomfret (Pampus argenteus) is a high-valued marine fish species in aquaculture, which is seriously threatened by various fish diseases. In this study, a new cell line derived from P. argenteus liver (PaL) was established and characterized. PaL cells mainly consisted of fibroblast-like morphology and multiplied well in Leibovitz's L-15 medium supplemented with 15% foetal bovine serum and 3 ng/mL basic fibroblast growth factor at 22°C. Amplification of the Cyt b gene confirmed that the origin of PaL cells as P. argenteus. Chromosome analysis revealed that PaL cells had a diploid Karyotyp. The PaL cells were efficiently transfected with pEGFP-N3 plasmids, indicating its potential application in foreign gene manipulation studies. The PaL cells were found to be susceptible to red sea bream iridovirus (RSIV) and the expression of immune-related gene (TLR5) and apoptosis-related genes (Bax, Cyt c3, CASP9) were upregulated. Furthermore, lipopolysaccharide and palmitic acid (PA) treatments decreased cell viability and up-regulated the expression of inflammation related genes (IL-8, IL-1ß). Meanwhile, PA incubation induced cell apoptosis by Bcl-2-regulated caspase activation. In conclusion, the newly established PaL cell line will be an appropriate in vitro tool for viral propagation and immune response.
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Enfermedades de los Peces , Perciformes , Animales , Peces , Perciformes/genética , Hígado , Línea CelularRESUMEN
Pampus argenteus is important for commercial fishery catch species and is an emerging target for aquaculture production. Notably, P. argenteus has a bizarre morphology and lacks pelvic fins. However, the reason for the lack of pelvic fins remains unclear, ultimately leading to frequent upside-down floating of P. argenteus during breeding and marked consumption of physical energy. Some lineages, including whales, fugu, snakes, and seahorse, independently lost the pelvic appendages over evolutionary time. Do different taxa employ the same molecular genetic pathways when they independently evolve similar developmental morphologies? Through analysis of the gene responsible for appendage localization, Hoxd9, it was discovered that the Hox domain was absent in the Hoxd9 gene of P. argenteus, and the Hoxd9b gene lacked the Hox9 activation region, a feature not observed in the Hoxd9 gene of other fish species. Interestingly, those distinctive characteristics are not observed in the Hoxd9 gene of other fish species. To determine the association between the Hoxd9 gene characteristics and the pelvic fin deletion in P. argenteus, the full-length cDNA of the Hoxd9a gene was cloned, and morphological observations of the species' juveniles were performed using stereomicroscopy and scanning electron microscopy. Thereafter, the tissue localization of Hoxd9a in the species was analyzed at the gene and protein levels. Based on the results, deletion of the Hoxd9a structural domain possibly leads to disruptions in the protein translation and the pelvic fin localization in P. argenteus during its early ontogenetic developmental stage, resulting in the absence of pelvic fins.
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Perciformes , Smegmamorpha , Animales , Genes Homeobox , Evolución Biológica , Peces/genética , Perciformes/genéticaRESUMEN
Photoperiod has a great influence on the growth and ovarian development and maturation of fishes. To analyse the effects of photoperiod on growth and ovarian development of an important marine economic fish, silver pomfret Pampus argenteus, short photoperiod group (L:D = 8:16), control group (L:D = 12:12) and long photoperiod group (L:D = 18:6) were set up for 60 days. The growth performance, ovarian development, changes in hormones and key enzyme activities in the hypothalamic-pituitary-gonadal (HPG) axis and expressions of key regulatory genes in the HPG axis were studied under different photoperiod conditions. The results showed that the final weight gain, body weight index, specific growth rate for weight, specific growth rate for length and average daily growth were the highest in the long photoperiod group, and the feed conversion rate was the lowest. Under long photoperiod condition, gonado-somatic index and hepato-somatic index were higher, ovarian maturity was better and expressions of HPG axis-related regulatory genes foxl2a, foxl2b, cyp19a1a, cyp19a1b, kiss, gpr54-2, gnrh2, fsh and lh were higher. When compared with the other two groups, in the long photoperiod group, the change trend of estradiol (E2) was consistent with those of luteinizing hormone, melatonin (MT) and kisspeptin, and the levels were higher on the 20th and 50th days. These results indicate that prolongation of the photoperiod can improve the growth performance of P. argenteus and promote ovary development and maturation. The authors speculate that photoperiod may regulate the ovarian activity of P. argenteus through MT and kisspeptin/gpr54 signalling pathways. The results show that photoperiod can regulate the ovarian development of P. argenteus, which would help in breaking the seasonal restrictions of animals and regulating an animal's reproductive cycle.
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Perciformes , Fotoperiodo , Femenino , Animales , Kisspeptinas , Hormona Luteinizante/metabolismo , Hormona Liberadora de Gonadotropina , Perciformes/fisiología , Peces/metabolismoRESUMEN
Cryptorchidism irritant (CI) infection is a major problem in the culturing process of silver pomfret (Pampus argenteus), which can result in rapid and massive death. However, there is limited information available on the immune response of silver pomfret infected by CI. To address this gap, we sampled naturally infected fish and observed milky white translucent oval CI trophozoites on the gills, body surface, and fin rays. Histological analysis showed that CI infection led to vacuolation of epithelial cells and a decrease in blood cells in the gills. We also performed transcriptome profiling of the gill, kidney complex, and spleen, generating 399,616,194 clean reads that assembled into 101,228 unigenes, which were annotated based on public databases. We detected 14,369 differentially expressed genes, and selected several key immune-related genes for further validation using RT-qPCR. The Graft-versus-host pathway and Allograft rejection pathway were enriched in the gills, leading to inflammation and ulceration. CI infection activated the immune system, increasing levels of interleukin-1 beta and MHC class II antigen, and also activated innate and acquired immune genes in silver pomfret. Furthermore, we measured the activities of five immune-related enzymes (SOD, AKP, CAT, CSH and ACP), which all increased to varying degrees after CI infection. Our findings enhance our understanding of the immune response of fish to parasitic infection and may contribute to the development of strategies to prevent high mortality in CI-stimulated fish in aquaculture.
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Criptorquidismo , Enfermedades de los Peces , Animales , Masculino , Irritantes , Peces/genética , Perfilación de la Expresión Génica/veterinaria , Inmunidad , TranscriptomaRESUMEN
Copper pollution might have a negative effect on collagen metabolism in fish. To test this hypothesis, we exposed an important economical fish, silver pomfret (Pampus argenteus), to three concentrations of Cu2+ for up to 21 days to simulate natural exposure to copper. With increasing copper exposure concentration and time, hematoxylin and eosin staining and picrosirius red staining revealed extensive vacuolization, cell necrosis, and tissue structure destruction, and a change of type and abnormal accumulation of collagen in the liver, intestine, and muscle tissues. To further study the mechanism of collagen metabolism disorder caused by copper exposure, we cloned and analyzed a key collagen metabolism regulation gene, timp, of silver pomfret. The full-length timp2b cDNA was 1035 bp with an open reading frame of 663 bp, encoding a protein of 220 amino acids. Copper treatment significantly increased the expression of akts, erks, and fgfs genes and decreased the mRNA and protein expression of Timp2b and MMPs. Finally, we constructed a silver pomfret muscle cell line (PaM) for the first time and used PaM Cu2+ exposure models (450 µM Cu2+ exposure for 9 h) to examine regulation function of the timp2b-mmps system. We knocked down or overexpressed timp2b in the model, and found that downregulation of mmps expression and upregulation of akt/erk/fgf were further aggravated in the timp2b- group (subjected to RNA interference), whereas some recovery was achieved in the timp2b+ group (overexpression). These results indicated that long-term excessive copper exposure can lead to tissue damage and abnormal collagen metabolism in fish, which might be caused by the alteration of akt/erk/fgf expression, which disrupts the effects of the timp2b-mmps system on extracellular matrix balance. The present study assessed the impact of copper on the collagen of fish and clarified its regulatory mechanism, providing a basis for toxicity of copper pollution study.
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Perciformes , Contaminantes Químicos del Agua , Animales , Cobre/toxicidad , Cobre/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Contaminantes Químicos del Agua/toxicidad , Regulación hacia Abajo , Perciformes/metabolismoRESUMEN
The pharyngeal sac is a comparatively rare organ in the digestive tract among teleost fishes. However, our understanding of this remarkable organ in the silver pomfret (Pampus argenteus) is limited. In the present study, we examined the various morphological and histological characteristics of the pharyngeal sac using histochemical techniques and electron microscopy. The pharyngeal sac showed unique characteristics such as well-developed muscular walls, weakly keratinized epithelium, numerous goblet cells, and needle-like processes on the papillae. The porous cavity of the papillae contained numerous adipocytes and was tightly enveloped by type I collagen fibers. These structures might provide mechanical protection and excellent biomechanical properties for grinding and shredding prey. A comparison of gene expression levels between the pharyngeal sac and esophagus using RNA-seq showed that phenotype-associated genes (epithelial genes and muscle genes) were upregulated, whereas genes related to nutrient digestion and absorption were downregulated in the pharyngeal sac. These results support the role of the pharyngeal sac in shredding and predigesting food. Overall, these findings provide a clearer understanding of the pharyngeal sac morphology and explain the morphological adaptations of the digestive tract for feeding on gelatinous prey. To our knowledge, this is the first report on pharyngeal sac gene expression in P. argenteus.
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Perciformes , Animales , Perciformes/genética , Peces , Tracto Gastrointestinal , Faringe , Células CaliciformesRESUMEN
Silver pomfret (Pampus argenteus) is one of the most important fishery products in the Indo-Pacific Ocean. Nonetheless, little is known about the genetic parameters of economic traits. To determine whether the selective breeding programme would improve economic traits, the authors evaluated the growth performance of the selected group and the control group at 60, 90 and 120 days, and the growth performance parameters of the selected group were higher than those of the control group. Through Pearson correlation analysis, the authors found that the morphological traits that are highly related to the weight of P. argenteus are body length and body height. Genetic gain and realized heritability for body weight were highest at day 90, which were 12.72% and 0.23%, respectively. Therefore, the authors speculate that day 90 may be a critical time for screening. The average coefficient of variation for body weight reached over 30%. All three morphological traits reached moderate realized heritability at day 90 after hatching. These implied that selective breeding has the potential to improve the growth traits of P. argenteus. In addition, the reproductive performance of P. argenteus parent fish was obviously improved after gonadal strengthening. These results provide important information for future breeding programmes for P. argenteus.
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Perciformes , Animales , Perciformes/genética , Peces/genética , Fenotipo , Peso Corporal/genética , Océano PacíficoRESUMEN
The black sea bream (Acanthopagrus schlegelii) is an important marine economic fish found on the southeast coast of China. Because of the frequent climate change, the salinity of the waters inhabited by A. schlegelii often decreases, which interferes with the fish's physiological homeostasis. The isotonic salinity of teleosts are usually lower than that of seawater, so maximum economic benefits cannot be obtained from conventional mariculture. This study was performed to preliminarily clarify the osmotic regulation and antioxidant mechanism of juvenile A. schlegelii and find an appropriate culture salinity value. We selected 5 psu, 10 psu, 15 psu, and 25 psu (control) to conduct physiological experiments for 96 h and growth experiments for 60 days. We found that the juvenile A. schlegelii could adjust their osmotic pressure within 12 h. The growth hormone and cortisol were found to be seawater-acclimating hormones, whereas prolactin was freshwater-acclimating hormone. The activity and mRNA expression of Na+/K+-ATPase showed a U-shaped trend with the decrease of in salinity at 12-96 h. Serum ion concentration and osmotic pressure remained at a relatively stable level after being actively adjusted from 6 to 12 h. At 96 h, the osmotic pressure of the serum isotonic point of juvenile A. schlegelii was approximately equal to that of water with 14.94 salinity. The number and volume of Cl--secreting cells in the gills decreased. The glomeruli were more developed and structurally sound, with the renal tubules increasing in diameter and the medial brush border being more developed; this may indicate a decrease in salt secretion and an enhanced reabsorption function in the low salinity groups. The activities of superoxide dismutase and catalase and concentration of malondialdehyde were the lowest in the 15 psu group. In addition, the culture conditions of the 15 psu group improved the feed conversion rate without significant differences in weight gain when compared with the control group. Our results show that 15 psu salinity may be the best parameter for obtaining the maximum economic benefits.
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Perciformes , Dorada , Animales , Osmorregulación , Antioxidantes/metabolismo , Dorada/metabolismo , Salinidad , Perciformes/fisiología , Estrés Salino , Branquias/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Agua de MarRESUMEN
Background: Silver pomfret (Pampus argenteus) is one of the most widely distributed and economically important pelagic fish species. However, an unique morphological feature of P. argenteus is the loss of pelvic fins, which can increase the energy requirement during food capture to some extent and is therefore not conducive to artificial culture. Tbx4/5 genes are highly conserved regulatory factors that regulate limb development in vertebrates and are in turn regulated by microRNAs (miRNAs). However, the miRNAs that directly regulate the Tbx4/5 genes in P. argenteus remain to be elucidated. Methods: The Tbx4/5 genes of P. argenteus were first cloned, and the small RNA transcriptomes were sequenced by high-throughput sequencing during the critical period of the fin development at days 1, 7, and 13 of hatching. The miRNAs regulating the Tbx4/5 genes of P. argenteus were subsequently predicted by bioinformatics analysis, and the related miRNAs were verified in vitro using a dual fluorescence reporter system. Results: A total of 662 miRNAs were identified, of which 257 were known miRNAs and 405 were novel miRNAs were identified. Compared to day 1, 182 miRNAs were differentially expressed (DE) on day 7, of which 77 and 105 miRNAs were downregulated and upregulated, respectively, while 278 miRNAs were DE on day 13, of which 136 and 142 miRNAs were downregulated and upregulated, respectively. Compared to day 13, four miRNAs were DE on day 7, of which three miRNAs were downregulated and one miRNA was upregulated. The results of hierarchical clustering of the miRNAs revealed that the DE genes were inversely expressed between days 1 and 7, and between days 1 and 13 of larval development, indicating that the larvae were in the peak stage of differentiation. However, the number of DE genes between days 7 and 13 of larval development was relatively small, suggesting the initiation of development. The potential target genes of the DE miRNAs were subsequently predicted, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of target genes were performed. The results suggested that the DE miRNAs were involved in growth, development, and signal transduction pathways, of which the Wnt and Fgfs signaling pathways are known to play important roles in the growth and development of fins. The results of dual fluorescence reporter assays demonstrated that miR-102, miR-301c, and miR-589 had a significant negative regulatory effect on the 3'-UTR of the Tbx4 gene, while miR-187, miR-201, miR-219, and miR-460 had a significant negative regulatory effect on the 3'-UTR of the Tbx5 gene. Altogether, the findings indicated that miRNAs play an important role in regulating the growth and development of pelvic fins in P. argenteus. This study provides a reference for elucidating the interactions between the miRNAs and target genes of P. argenteus in future studies.
Asunto(s)
MicroARNs , Perciformes , Animales , MicroARNs/genética , Perciformes/genética , Transducción de Señal , Genoma , Redes Reguladoras de GenesRESUMEN
Insulin-like growth factor 3 plays an important role in gonad development in teleost fish. Previous studies found that igf3 was specifically expressed in gonads of silver pomfret (Pampus argenteus). Unlike in other fish, IGF3 is a membrane protein in silver pomfret, and its specific role in gonads is unclear. Herein, we explored the importance of IGF3 in oogenesis and spermatogenesis in silver pomfret by analyzing gene expression and cellular localization. During follicular development, igf3 was detected in ovaries at both mRNA and protein levels during the critical stages of vitellogenesis (IV-VI). Localization analysis detected igf3 mRNA and protein in somatic cells, including theca and granulosa cells around oocytes. Similar to cathepsin L and cathepsin K, igf3 was consistently expressed in ovaries during vitellogenesis, suggesting that it might play a key role in vitellogenesis of oocytes. During spermatogenesis, igf3 mRNA and protein levels were high in stages II, IV, and V, similar to sycp3 and dmc1, and the highest igf3 mRNA and protein levels were reached in stage VI. Furthermore, igf3 mRNA and protein were detected in spermatogonia, spermatocytes, spermatids, and surrounding Sertoli cells, but not in spermatozoon, indicating that IGF3 might be involved in differentiation and meiosis of spermatogonia.
Asunto(s)
Perciformes , Somatomedinas , Masculino , Femenino , Animales , Catepsina L/metabolismo , Catepsina K/metabolismo , Estaciones del Año , Somatomedinas/genética , Somatomedinas/metabolismo , Gónadas/metabolismo , Perciformes/genética , Perciformes/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Peces/metabolismo , Proteínas de la Membrana/metabolismoRESUMEN
Understanding the metabolic effects of fatty acids on fish intestine is critical to the substitution of fish oil with vegetable oils in aquaculture. In this study, the effects of eicosapentaenoic acid (EPA) and palmitic acid (PA) on fish intestine were evaluated in vitro and in vivo. As the first step for in vitro study, an intestinal cell line (SPIF) was established from silver pomfret (Pampus argenteus). Thereafter, the effects of EPA and PA on cell viability, prostaglandin E2 (PGE2) production, and the expression of genes related to heat shock response, inflammation, extracellular matrix (ECM) formation and degradation were examined in SPIF cells. Finally, these metabolic effects of EPA and PA on the intestine were examined in zebrafish (Danio rerio) larvae. Results showed that all tested fatty acids (PA, oleic acid, linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid) except EPA reduced SPIF viability to distinct degrees at the same concentrations. PA decreased SPIF viability accompanied by an increase in PGE2 level. Meanwhile, PA increased the expression of genes related to heat shock response (grp78, grp94, hsp70, and hsp90) and inflammation (nf-κb, il-1ß, and cox2). Furthermore, PA reduced the expression of collagen type I (col1a1a and col1a1b) and extracellular matrix (ECM) degradation-related gene mmp2, while up-regulating timp2 mRNA expression. In vivo, PA also increased hsp70, il-1ß, and cox2 mRNA levels and limited the expression of collagen type I in the larval zebrafish intestine. Interestingly, the combination of EPA and PA partially recovered the PA-induced changes in cell viability, PGE2 production, and mRNA expression in vitro and in vivo. These results suggest that PA may result in heat shock and inflammatory responses, as well as alter ECM formation and degradation in fish intestine, while EPA could at least partially mitigate these negative effects caused by PA.