Withania somnifera(L.)Dunal(WS),or Ashwagandha,is used clinically against arthritis,anxiety and insomnia etc,however,its potential in aquafeeds is largely unexplored.We investigated the stress-alleviation and hepatopr...Withania somnifera(L.)Dunal(WS),or Ashwagandha,is used clinically against arthritis,anxiety and insomnia etc,however,its potential in aquafeeds is largely unexplored.We investigated the stress-alleviation and hepatoprotective mechanisms of dietary WS supplementation in adult female darkbarbel catfish.Fish were fed with WS dietary for 5 weeks,subjected to a physical stressor(saline injection),and sampled.Brain were processed for RNA-seq to identify differentially expressed genes(DEGs)linked to stress;serum were assayed for stress-and immune-related biochemical markers;livers were examined for lipid content(Oil Red O staining)and proliferation(PCNA immunos-taining).Network pharmacology were employed to construct a"compound-target"net-work:The bioactive compounds of WS were retrieved from ChEBI and PCIDB,probable targets predicted via Swiss Target Prediction,and the“WS-ingredient-target”regulatory network was constructed using Cytoscape;key ligand-protein interactions were validated by molecular docking.Findings were replicated in juvenile fish and in SG3 cells challenged with Withanolide A.Physical stress evoked 1451 DEGs in control brains,whereas WS-supplemented reduced this to 397,indicating marked mitigation of the oxid-ative-and immune-stress response.Network pharmacology and molecular docking pre-dicted that 13 bioactive compounds in WS,especially Withanolide A and Withanolide J,can interact with targets such as MAPK8,CRHR1,NR3C2,and IARS1,being associated with stress and liver function regulation respectively.Moreover,it was proved that Withanolide A could significantly modulate stress response in juveniles and enhanced pro-liferation potency of SG3 cells.Intriguingly,in theadult female darkbarbel catfish,dietary WS lowered serum cortisol,glucose,ROS,TNF-α,and IL-6(P<0.05),up-regulated hepatocyte PCNA expression,and allievated stress-induced liver injury.These findings provide novel insights and vital basis for elucidating the mechanisms whereby herbs,including WS act in stress-relief and hepatoprotection in darkbarbel catfish.And provide a framework for advancing traditional Chinese medicine(TCM)applications in aquaculture.展开更多
Background In intensive aquaculture systems,the frequent incidence of enteritis reduces production efficiency and results in significant economic losses.Protein feeds account for 40%–60%of aquafeed expenses,and with ...Background In intensive aquaculture systems,the frequent incidence of enteritis reduces production efficiency and results in significant economic losses.Protein feeds account for 40%–60%of aquafeed expenses,and with the growth of intensive aquaculture,demand for fishmeal as a key protein source outstrips supply,driving up prices.This study investigated the therapeutic potential of reducing dietary protein levels by 3%and adding enzymatic cottonseed protein(ECP)in juvenile yellow catfish with dextran sulfate sodium(DSS)-induced enteritis.Methods A total of 1,260 healthy juvenile yellow catfish(Pelteobagrus fulvidraco),with an average body weight of 5.90±0.05 g,were randomly allocated into 7 experimental groups,each with 3 replicates.The fish were fed one of seven diets for 10 weeks:a normal-protein diet(42%;NP)and 6 low-protein diets(39%;LP)supplemented with graded levels of ECP at 0%(ECP0),1%(ECP1),2%(ECP2),3%(ECP3),4%(ECP4),and 5%(ECP5),respectively.Subsequently,48 fish from each group were selected to receive 1 mL of 6%DSS solution.Results Our findings demonstrated that:(1)The DSS+ECP0 group aggravated DSS-induced enteritis in juvenile yellow catfish compared to the DSS+NP group.(2)Dietary supplementation of ECP in LP diets significantly enhanced the enzymatic activity and levels of immunoreactive substances,including LZM,C3,C4,and ACP(P<0.05).Mechanistically,first,ECP supplementation modulated macrophage polarization by inhibiting the M1 phenotype while promoting the M2 phenotype,potentially through the JAK-STAT signaling pathway;second,dietary ECP suppressed the phosphorylation cascade of key necroptosis-related proteins,including RIP1,RIP3,and MLKL,potentially via the NF-κB and MAPK signaling pathways.(3)The DSS+ECP2 group demonstrated comparable or superior efficacy to the DSS+NP group in mitigating DSS-induced intestinal enteritis.Conclusions Our results demonstrated that ECP can alleviate DSS-induced enteritis by regulating macrophage polarization and reducing necroptosis.Furthermore,ECP supplementation effectively counteracted the exacerbation of enteritis caused by dietary protein reduction.These findings highlighted the effectiveness and feasibility of ECP in alleviating enteritis and saving protein.展开更多
The Clock gene,a key molecule in circadian systems,is widely distributed in the animal kingdom. We isolated a 936-bp partial c DNA sequence of the C lock gene( Pva- clock) from the darkbarbel catfish P elteobagrus vac...The Clock gene,a key molecule in circadian systems,is widely distributed in the animal kingdom. We isolated a 936-bp partial c DNA sequence of the C lock gene( Pva- clock) from the darkbarbel catfish P elteobagrus vachelli that exhibited high identity with C lock genes of other species of fish and animals(65%–88%). The putative domains included a basic helix-loop-helix(b HLH) domain and two period-ARNT-single-minded(PAS) domains,which were also similar to those in other species of fish and animals. P va- Clock was primarily expressed in the brain,and was detected in all of the peripheral tissues sampled. Additionally,the pattern of P va- Clock expression over a 24-h period exhibited a circadian rhythm in the brain,liver and intestine,with the acrophase at zeitgeber time 21:35,23:00,and 23:23,respectively. Our results provide insight into the function of the molecular C lock of P. vachelli.展开更多
Circadian clock genes are crucial for generating and sustaining most rhythmic daily functions in the animal kingdom,which entrain the rhythms of biochemical,physiological,and behavioural processes.To better understand...Circadian clock genes are crucial for generating and sustaining most rhythmic daily functions in the animal kingdom,which entrain the rhythms of biochemical,physiological,and behavioural processes.To better understand the molecular oscillations of the circadian rhythms in darkbarbel catfish(Pelteobagrus vachellii),we isolated and characterized two circadian clock genes in P.vachellii,period 1(per1),and period 3(per3).The circadian clock gene per1 was found to encode a 1428-amino acid polypeptide,including PER-ARNT-SIM(PAS)dimerisation domains,a PAS-associated C-terminal motif(PAC),a short mutable domain(S/M),and a nuclear export signal(NES).The 4902-bp per3 cDNA includes an open reading frame encoding a 1292-amino acid residue polypeptide with a PER-ARNT-SIM(PAS)domain,cytoplasmic localisation domain(CLD),interaction site(TIS),and a nuclear localisation signal(NLS).The per1 and per3 gene was constitutively expressed in all examined tissues.Moreover,per1 expression within a light/dark cycles showed rhythmic expression in the diencephalon,brain,liver and intestine,with the acrophase at 15:15,12:52,7:51 and 12:55,respectively.Daily expression of per3 was rhythmic in the diencephalonbrain,liver and intestine,with the acrophase at 8:15,9:54,10:39,and 10:25 h,respectively.These findings expand our understanding of circadian mechanism at the molecular level in this species.展开更多
Over the past five years, an epidemic disease broke out in Pelteobagrus fulvidraco ponds of Zhejiang Province. The diseased fish mainly exhibits head splitting and surface bleeding; dissection results reveal hepatonep...Over the past five years, an epidemic disease broke out in Pelteobagrus fulvidraco ponds of Zhejiang Province. The diseased fish mainly exhibits head splitting and surface bleeding; dissection results reveal hepatonephromegaly and abdominal bleeding. A bacterial strain HSY201301 was isolated from the liver tissue of P. fulvidraco with typical symptoms. Artificial infection experiment confirmed that the isolated strain had a strong virulence to healthy P. fidvidraco, leading to similar symptoms to naturally infected P. fulvidraco. The isolated strain was identified as an Edwardsiella tarda strain according to conventional morphological, physiological, biochemical characteristics and 16S rRNA gene sequence. Results of drug susceptibility test indicated that the isolated strain was sensitive to cipro- floxacin, doxitard, penicillin, doxycycline, and rocephin. This study laid solid foundation for effective prevention and control of E. tarda.展开更多
Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and ...Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and analyze the different expression of C7 mRNA in fish fed during either the day or at night and then challenged with Aeromonas hydrophila infection. The P v-C7 cDNA of Pelteobagrus vachellii contained 2 647 bp with an open reading frame encoding a protein of 818 amino acids. Multiple sequences analysis indicated that P v-C7 included eight domains, which was similar to results for other species. Quantitative PCR analysis showed that P v-C7 was mainly expressed in the liver, spleen, intestine and head kidney tissues of healthy P. vachellii. Quantitative PCR analysis showed that C7 mRNA transcript in the liver, spleen and head kidney also increased significantly when the fish were fed at nighttime(20:00). In addition, the expression of Pv-C7 mRNA significantly increased with A. hydrophila challenge in the liver(48–96 h), spleen and head kidney(12–96 h) tissues of P. vachellii. Pv-C7 mRNA expression of the fish fed at nighttime showed significant higher than that in the fish fed at day time at 12–48 h in head kidney and 12–24 h in spleen. This study indicates that altering the feeding time from daytime to nighttime could increase P v-C7 mRNA expression, and feeding time may af fect the immune response involving C7.展开更多
Although the effects of diet on intestinal microbiotas have been well investigated,the effect of feeding time on the rhythm of gut microbiota remains uncertain.A 9-week feeding trial on Pelteobagrus fulvidraco was con...Although the effects of diet on intestinal microbiotas have been well investigated,the effect of feeding time on the rhythm of gut microbiota remains uncertain.A 9-week feeding trial on Pelteobagrus fulvidraco was conducted.Two triplicate groups of fish were fed identically either at 8:00(day)or at 20:00(night).After 9 weeks,three fish from each cage were sacrificed every 4 h for 24 h.The intestinal contents were analyzed using high-throughput sequencing.Three phyla(Fusobacteria,Proteobacteria,and Verrucomicrobia),and three genera(Cetobacterium,Akkermansia,and Clostridium)were dominant at every time point.Moreover,33.02%of detected amplicon sequence variants showed cyclical variations in fish fed at 20:00,and 3.47%in fish fed at 8:00.Among the top 20 genera,17 showed cyclical variations in the 20:00 group,and only two in the 8:00 group.Rhodobacter,Ralstonia,Mycobacterium,Lactococcus,Halomonas,Akkermansia,and Acinetobacter contributed more to the predicted functional pathways.Moreover,144 and 38 pathways exhibited daily cyclical fluctuations in fish fed at 20:00 and 8:00,respectively.Overall,certain intestinal microorganisms showed a circadian rhythm in P.fulvidraco,and this circadian rhythm was affected by shifted feeding times.展开更多
Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16...Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16S rDNA sequence analysis. Five virulence factors were detected, then artificial infection experiment and histopathological method were carried out. These results showed that strain YER6022 was one of Y. enterocolitica family members. In addition, ail, ystb, virF, yadA and HPIint were dectected. In artificial infection experiment, with 80% mortality and 100% morbidity, injected Pelteobagrus vachellis showed red swollen of the anus, abdomen swelling and fim bleeding. There existed serious hyperaemia and edema in kidney, spleen, intestine and liver at the light microscope. Ultrastructural observation indicated that mitochondria of the liver, kidney, spleen and intestine swelled and mitochondrial cristae broke. The data had further shed light on its pathogenicity in Pelteobagrus vachelli. It would benefit for further studies on pathogenesis ofPelteobagrus vachelli infected with Y. enterocolitica.展开更多
Androgenesis was the especial zoogamy that the germ plasma of offspring was from the agnate. In this study the eggs of Yellow catfish （Pelteobagrus fulvidraco） were irradiated by UV suspending in the synthetic ovari...Androgenesis was the especial zoogamy that the germ plasma of offspring was from the agnate. In this study the eggs of Yellow catfish （Pelteobagrus fulvidraco） were irradiated by UV suspending in the synthetic ovarian fluid （OF）, and the total dosage of UV irradiation was 220 mJ·cm^-2. Diploid could be induced by heat shock （40℃, 2 min, 3 min） with different time period after fertilization （15-37 min）. The result showed that heat shock with 2 min was better than 3 min; there were two apices of induction in 17-21 min and 27-31 min after fertilization. The highest hatching rate was 3.30% at 29 min after fertilization, and the difference between two apices of induction was unobvious.展开更多
Mature wild-type yellow catfish( Pelteobagrus fulvidraco Richardson) individuals with excellent traits have been screened from the Yangtze River as broodstock to establish the germplasm bank of pure-line yellow catfis...Mature wild-type yellow catfish( Pelteobagrus fulvidraco Richardson) individuals with excellent traits have been screened from the Yangtze River as broodstock to establish the germplasm bank of pure-line yellow catfish by artificial gynogenesis technique and hormonal sex reversal method. Based on pure lines of yellow catfish,super-males and physiological females of yellow catfish were selected by GMT technique,hormonal sex reversal method and test-crossing to establish the germplasm bank of YY physiological females( YY♀). The propagation system of male yellow catfish( XY♂) was established based on the combination of super-males( YY♂) and pure-line female( XX♀) for large-scale production of pure-line yellow catfish males,which effectively overcome the disadvantages in the production of common fingerlings and male fingerlings using low-grade fish with slow growth and small size at the bottom of the fish grader as broodfish,such as progeny germplasm degeneration,loss of growth vigor and reduction of breeding benefits. The technical route of breeding pure-line YY physiological females( YY♀) and YY super-males( YY♂) laid the foundation for large-scale production of environmentally friendly yellow catfish males with pure germplasm and strong stress resistance,and provided an efficient,stable,healthy,environmentally friendly,energy-saving and income-increasing approach for sustainable development of yellow catfish breeding industry.展开更多
[Objectives] This study was conducted to study early reproduction techniques of yellow catfish(Pelteobagrus fulvidraco) in Jianghan Plain. [Methods] Parents of P. fulvidraco were cultured by the methods of artificial ...[Objectives] This study was conducted to study early reproduction techniques of yellow catfish(Pelteobagrus fulvidraco) in Jianghan Plain. [Methods] Parents of P. fulvidraco were cultured by the methods of artificial temperature control and nutrition enhancement. [Results] After culture, the body weight, gonad weight, maturity coefficient and egg diameter of P. fulvidraco increased gradually. Up to April 30, the gonad weight of the female parents of P. fulvidraco cultured in greenhouses was significantly higher than that of the parents under natural conditions(P<0.05), 54% higher than that of the parents naturally cultured at the same period;the maturity coefficient of the parents cultured under strengthened conditions was also significantly higher than that of the parents under natural conditions at the same period(P<0.05);and the ovaries of the strengthened parents were orange yellow and full of eggs, and the number of eggs per fish was relatively high. In early May, the parents cultured under strengthened conditions were induced to spawn artificially. The average induced spawning rate and fertilization rate reached 86.7% and 71.6%, respectively, reaching the respective normal level. The gonad maturity of P. fulvidraco cultured under strengthened conditions was 15 d earlier than that under natural conditions, resulting in mass production of early-propagated larvae of P. fulvidraco. [Conclusions] In Jianghan plain area, artificial propagation can be achieved in early May by means of artificial temperature control and strengthened culture, which is 20 d ahead of natural conditions.展开更多
This experiment was conducted to investigate the effects of dietary arginine levels on growth performance, body composition, serum biochemical indices and resistance ability against ammonia-nitrogen stress in juvenile...This experiment was conducted to investigate the effects of dietary arginine levels on growth performance, body composition, serum biochemical indices and resistance ability against ammonia-nitrogen stress in juvenile yellow catfish(Pelteobagrus fulvidraco). Five isonitrogenous and isolipidic diets(42%protein and 9% lipid) were formulated to contain graded levels of arginine(2.44%, 2.64%, 2.81%, 3.01% and3.23% of diet), by supplementing L-Arginine HCI. Seven hundred juvenile yellow catfish with an initial average body weight of 1.13 ± 0.02 g were randomly divided into 5 groups with 4 replicates of 35 fish each and each group was fed one of the diets. After 56 d feeding, fish were exposed to 100 mg/L of ammonia-nitrogen for 72 h. The results showed that weight gain(WG) and specific growth rate(SGR) in2.64% and 2.81% groups were significantly higher than those in 3.23% group(P < 0.05). The feed conversation ratio(FCR) in 2,64%, 2,81% and 3.01% groups was significantly decreased when compared with3,23% group. The protein efficiency ratio(PER) in 2.64% group was significantly higher than that in 2.44%and 3.23% groups(P < 0.05). The condition factor(CF) of fish was significantly higher in 2.81% group than that in 2,44% group(P < 0.05). Dietary arginine levels had no significant effect on hepatosomatic index(HSI), viscerosomatic index(VSI), and whole-body dry matter, crude protein, crude lipid, ash contents, as well as serum total protein(TP), triglyceride(TG), glucose(GLU), urea nitrogen(UN) contents and aspartate aminotransferase(AST), alanine aminotransferase(ALT) activities(P> 0.05). After the fish were challenged to ammonia-nitrogen for 72 h, their cumulative mortality rate in 2.81% group was significantly lower than that in 2.44% group(P < 0.05). The results suggested that dietary arginine level at 2.81%could optimize anti-ammonia-nitrogen stress ability of juvenile yellow catfish and a level of 3.23%arginine seemed to depress the growth performance of fish and decreased their tolerance to the ammonia-nitrogen stress under current study. A quadratic regression analysis based on WG indicated that the optimal dietary arginine requirement of juvenile yellow catfish was estimated to be 2.74% of the diet(6.45% of dietary protein) under current culture conditions.展开更多
In this study,three members of the Bmp family were cloned and characterized in yellow catfish Pelteobagrus fulvidraco,including Bmp2a,Bmp4 and Bmp9.The predicted amino acid sequences of P.fulvidraco Bmp2a,Bmp4 and Bmp...In this study,three members of the Bmp family were cloned and characterized in yellow catfish Pelteobagrus fulvidraco,including Bmp2a,Bmp4 and Bmp9.The predicted amino acid sequences of P.fulvidraco Bmp2a,Bmp4 and Bmp9 showed the characteristic domains of the Bmp family,including an N-terminal signal peptide,Arg-X-XArg site,TGF-βfamily signature and seven conserved cysteines,indicating that function is likely to have been conserved during evolution.mRNAs of the three Bmp genes had a variable level of expression in tissues.Compared to the control diet,a high fat diet tended to down-regulate the mRNA expression of Bmp2a,Bmp4 and Bmp9 in mesenteric fat,liver and ovary,while it tended to up-regulate their mRNA levels in muscle and kidney.The responses to dietary lipid status and the potential role in lipid metabolism have not previously been reported and reinforces the idea of their multiple functions.Our findings provide the first data about the potential role of the Bmp family in lipid metabolism in teleost.展开更多
文摘Withania somnifera(L.)Dunal(WS),or Ashwagandha,is used clinically against arthritis,anxiety and insomnia etc,however,its potential in aquafeeds is largely unexplored.We investigated the stress-alleviation and hepatoprotective mechanisms of dietary WS supplementation in adult female darkbarbel catfish.Fish were fed with WS dietary for 5 weeks,subjected to a physical stressor(saline injection),and sampled.Brain were processed for RNA-seq to identify differentially expressed genes(DEGs)linked to stress;serum were assayed for stress-and immune-related biochemical markers;livers were examined for lipid content(Oil Red O staining)and proliferation(PCNA immunos-taining).Network pharmacology were employed to construct a"compound-target"net-work:The bioactive compounds of WS were retrieved from ChEBI and PCIDB,probable targets predicted via Swiss Target Prediction,and the“WS-ingredient-target”regulatory network was constructed using Cytoscape;key ligand-protein interactions were validated by molecular docking.Findings were replicated in juvenile fish and in SG3 cells challenged with Withanolide A.Physical stress evoked 1451 DEGs in control brains,whereas WS-supplemented reduced this to 397,indicating marked mitigation of the oxid-ative-and immune-stress response.Network pharmacology and molecular docking pre-dicted that 13 bioactive compounds in WS,especially Withanolide A and Withanolide J,can interact with targets such as MAPK8,CRHR1,NR3C2,and IARS1,being associated with stress and liver function regulation respectively.Moreover,it was proved that Withanolide A could significantly modulate stress response in juveniles and enhanced pro-liferation potency of SG3 cells.Intriguingly,in theadult female darkbarbel catfish,dietary WS lowered serum cortisol,glucose,ROS,TNF-α,and IL-6(P<0.05),up-regulated hepatocyte PCNA expression,and allievated stress-induced liver injury.These findings provide novel insights and vital basis for elucidating the mechanisms whereby herbs,including WS act in stress-relief and hepatoprotection in darkbarbel catfish.And provide a framework for advancing traditional Chinese medicine(TCM)applications in aquaculture.
基金National Science Fund for Distinguished Young Scholars of China(32425056)National Natural Science Foundation of China(U23A20250)+2 种基金the earmarked fund for CARS(CARS-45)the National Key R&D Program of China(2023YFD2400600)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15).
文摘Background In intensive aquaculture systems,the frequent incidence of enteritis reduces production efficiency and results in significant economic losses.Protein feeds account for 40%–60%of aquafeed expenses,and with the growth of intensive aquaculture,demand for fishmeal as a key protein source outstrips supply,driving up prices.This study investigated the therapeutic potential of reducing dietary protein levels by 3%and adding enzymatic cottonseed protein(ECP)in juvenile yellow catfish with dextran sulfate sodium(DSS)-induced enteritis.Methods A total of 1,260 healthy juvenile yellow catfish(Pelteobagrus fulvidraco),with an average body weight of 5.90±0.05 g,were randomly allocated into 7 experimental groups,each with 3 replicates.The fish were fed one of seven diets for 10 weeks:a normal-protein diet(42%;NP)and 6 low-protein diets(39%;LP)supplemented with graded levels of ECP at 0%(ECP0),1%(ECP1),2%(ECP2),3%(ECP3),4%(ECP4),and 5%(ECP5),respectively.Subsequently,48 fish from each group were selected to receive 1 mL of 6%DSS solution.Results Our findings demonstrated that:(1)The DSS+ECP0 group aggravated DSS-induced enteritis in juvenile yellow catfish compared to the DSS+NP group.(2)Dietary supplementation of ECP in LP diets significantly enhanced the enzymatic activity and levels of immunoreactive substances,including LZM,C3,C4,and ACP(P<0.05).Mechanistically,first,ECP supplementation modulated macrophage polarization by inhibiting the M1 phenotype while promoting the M2 phenotype,potentially through the JAK-STAT signaling pathway;second,dietary ECP suppressed the phosphorylation cascade of key necroptosis-related proteins,including RIP1,RIP3,and MLKL,potentially via the NF-κB and MAPK signaling pathways.(3)The DSS+ECP2 group demonstrated comparable or superior efficacy to the DSS+NP group in mitigating DSS-induced intestinal enteritis.Conclusions Our results demonstrated that ECP can alleviate DSS-induced enteritis by regulating macrophage polarization and reducing necroptosis.Furthermore,ECP supplementation effectively counteracted the exacerbation of enteritis caused by dietary protein reduction.These findings highlighted the effectiveness and feasibility of ECP in alleviating enteritis and saving protein.
基金Supported by the National Natural Science Foundation of China(No.31402305)the Educational Commission of Sichuan Province of China(No.14ZA0249)+1 种基金the Key Technologies R&D Program of Neijiang,Sichuan,China(No.12108)the College Students’ Scientific Research Project of Neijiang Normal University(Nos.13NSD-66,13NSD-77)
文摘The Clock gene,a key molecule in circadian systems,is widely distributed in the animal kingdom. We isolated a 936-bp partial c DNA sequence of the C lock gene( Pva- clock) from the darkbarbel catfish P elteobagrus vachelli that exhibited high identity with C lock genes of other species of fish and animals(65%–88%). The putative domains included a basic helix-loop-helix(b HLH) domain and two period-ARNT-single-minded(PAS) domains,which were also similar to those in other species of fish and animals. P va- Clock was primarily expressed in the brain,and was detected in all of the peripheral tissues sampled. Additionally,the pattern of P va- Clock expression over a 24-h period exhibited a circadian rhythm in the brain,liver and intestine,with the acrophase at zeitgeber time 21:35,23:00,and 23:23,respectively. Our results provide insight into the function of the molecular C lock of P. vachelli.
基金Supported by the National Natural Science Foundation of China(No.31402305)the Sichuan Science and Technology Program(Nos.2017JY0161,2018NZ0119)。
文摘Circadian clock genes are crucial for generating and sustaining most rhythmic daily functions in the animal kingdom,which entrain the rhythms of biochemical,physiological,and behavioural processes.To better understand the molecular oscillations of the circadian rhythms in darkbarbel catfish(Pelteobagrus vachellii),we isolated and characterized two circadian clock genes in P.vachellii,period 1(per1),and period 3(per3).The circadian clock gene per1 was found to encode a 1428-amino acid polypeptide,including PER-ARNT-SIM(PAS)dimerisation domains,a PAS-associated C-terminal motif(PAC),a short mutable domain(S/M),and a nuclear export signal(NES).The 4902-bp per3 cDNA includes an open reading frame encoding a 1292-amino acid residue polypeptide with a PER-ARNT-SIM(PAS)domain,cytoplasmic localisation domain(CLD),interaction site(TIS),and a nuclear localisation signal(NLS).The per1 and per3 gene was constitutively expressed in all examined tissues.Moreover,per1 expression within a light/dark cycles showed rhythmic expression in the diencephalon,brain,liver and intestine,with the acrophase at 15:15,12:52,7:51 and 12:55,respectively.Daily expression of per3 was rhythmic in the diencephalonbrain,liver and intestine,with the acrophase at 8:15,9:54,10:39,and 10:25 h,respectively.These findings expand our understanding of circadian mechanism at the molecular level in this species.
文摘Over the past five years, an epidemic disease broke out in Pelteobagrus fulvidraco ponds of Zhejiang Province. The diseased fish mainly exhibits head splitting and surface bleeding; dissection results reveal hepatonephromegaly and abdominal bleeding. A bacterial strain HSY201301 was isolated from the liver tissue of P. fulvidraco with typical symptoms. Artificial infection experiment confirmed that the isolated strain had a strong virulence to healthy P. fidvidraco, leading to similar symptoms to naturally infected P. fulvidraco. The isolated strain was identified as an Edwardsiella tarda strain according to conventional morphological, physiological, biochemical characteristics and 16S rRNA gene sequence. Results of drug susceptibility test indicated that the isolated strain was sensitive to cipro- floxacin, doxitard, penicillin, doxycycline, and rocephin. This study laid solid foundation for effective prevention and control of E. tarda.
基金Supported by the National Natural Science Foundation of China(No.31402305)the Natural Science Foundation of Sichuan Province(No.2017JY0161)the Educational Commission of Sichuan Province of China(No.14ZA0249)
文摘Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and analyze the different expression of C7 mRNA in fish fed during either the day or at night and then challenged with Aeromonas hydrophila infection. The P v-C7 cDNA of Pelteobagrus vachellii contained 2 647 bp with an open reading frame encoding a protein of 818 amino acids. Multiple sequences analysis indicated that P v-C7 included eight domains, which was similar to results for other species. Quantitative PCR analysis showed that P v-C7 was mainly expressed in the liver, spleen, intestine and head kidney tissues of healthy P. vachellii. Quantitative PCR analysis showed that C7 mRNA transcript in the liver, spleen and head kidney also increased significantly when the fish were fed at nighttime(20:00). In addition, the expression of Pv-C7 mRNA significantly increased with A. hydrophila challenge in the liver(48–96 h), spleen and head kidney(12–96 h) tissues of P. vachellii. Pv-C7 mRNA expression of the fish fed at nighttime showed significant higher than that in the fish fed at day time at 12–48 h in head kidney and 12–24 h in spleen. This study indicates that altering the feeding time from daytime to nighttime could increase P v-C7 mRNA expression, and feeding time may af fect the immune response involving C7.
基金Supported by the Sichuan Science and Technology Program(Nos.2021YFYZ0015,2023NSFSC0241)。
文摘Although the effects of diet on intestinal microbiotas have been well investigated,the effect of feeding time on the rhythm of gut microbiota remains uncertain.A 9-week feeding trial on Pelteobagrus fulvidraco was conducted.Two triplicate groups of fish were fed identically either at 8:00(day)or at 20:00(night).After 9 weeks,three fish from each cage were sacrificed every 4 h for 24 h.The intestinal contents were analyzed using high-throughput sequencing.Three phyla(Fusobacteria,Proteobacteria,and Verrucomicrobia),and three genera(Cetobacterium,Akkermansia,and Clostridium)were dominant at every time point.Moreover,33.02%of detected amplicon sequence variants showed cyclical variations in fish fed at 20:00,and 3.47%in fish fed at 8:00.Among the top 20 genera,17 showed cyclical variations in the 20:00 group,and only two in the 8:00 group.Rhodobacter,Ralstonia,Mycobacterium,Lactococcus,Halomonas,Akkermansia,and Acinetobacter contributed more to the predicted functional pathways.Moreover,144 and 38 pathways exhibited daily cyclical fluctuations in fish fed at 20:00 and 8:00,respectively.Overall,certain intestinal microorganisms showed a circadian rhythm in P.fulvidraco,and this circadian rhythm was affected by shifted feeding times.
基金Supported by the Science&Technology Department of Sichuan Province(2013FZ0014)the Construction Project of the Postgraduate Academic Degree in Southwest University for Nationalities(2013XWD-S071007)
文摘Yersinia enterocolitica is an important zoonotic pathogen that can induce disease outbreaks in a wide host range. Strain YER6022 was isolated from Pelteobagrus vachelli and identified using bacterial morphology and 16S rDNA sequence analysis. Five virulence factors were detected, then artificial infection experiment and histopathological method were carried out. These results showed that strain YER6022 was one of Y. enterocolitica family members. In addition, ail, ystb, virF, yadA and HPIint were dectected. In artificial infection experiment, with 80% mortality and 100% morbidity, injected Pelteobagrus vachellis showed red swollen of the anus, abdomen swelling and fim bleeding. There existed serious hyperaemia and edema in kidney, spleen, intestine and liver at the light microscope. Ultrastructural observation indicated that mitochondria of the liver, kidney, spleen and intestine swelled and mitochondrial cristae broke. The data had further shed light on its pathogenicity in Pelteobagrus vachelli. It would benefit for further studies on pathogenesis ofPelteobagrus vachelli infected with Y. enterocolitica.
基金Supported by Science Project of Heilongjiang Province(GC03B510)
文摘Androgenesis was the especial zoogamy that the germ plasma of offspring was from the agnate. In this study the eggs of Yellow catfish （Pelteobagrus fulvidraco） were irradiated by UV suspending in the synthetic ovarian fluid （OF）, and the total dosage of UV irradiation was 220 mJ·cm^-2. Diploid could be induced by heat shock （40℃, 2 min, 3 min） with different time period after fertilization （15-37 min）. The result showed that heat shock with 2 min was better than 3 min; there were two apices of induction in 17-21 min and 27-31 min after fertilization. The highest hatching rate was 3.30% at 29 min after fertilization, and the difference between two apices of induction was unobvious.
基金Supported by Implementation Plan of Subsidy Project for the Reform and Construction of Grassroots Agricultural Technology Extension System
文摘Mature wild-type yellow catfish( Pelteobagrus fulvidraco Richardson) individuals with excellent traits have been screened from the Yangtze River as broodstock to establish the germplasm bank of pure-line yellow catfish by artificial gynogenesis technique and hormonal sex reversal method. Based on pure lines of yellow catfish,super-males and physiological females of yellow catfish were selected by GMT technique,hormonal sex reversal method and test-crossing to establish the germplasm bank of YY physiological females( YY♀). The propagation system of male yellow catfish( XY♂) was established based on the combination of super-males( YY♂) and pure-line female( XX♀) for large-scale production of pure-line yellow catfish males,which effectively overcome the disadvantages in the production of common fingerlings and male fingerlings using low-grade fish with slow growth and small size at the bottom of the fish grader as broodfish,such as progeny germplasm degeneration,loss of growth vigor and reduction of breeding benefits. The technical route of breeding pure-line YY physiological females( YY♀) and YY super-males( YY♂) laid the foundation for large-scale production of environmentally friendly yellow catfish males with pure germplasm and strong stress resistance,and provided an efficient,stable,healthy,environmentally friendly,energy-saving and income-increasing approach for sustainable development of yellow catfish breeding industry.
基金Supported by The Technological Innovation Special Project of Hubei Province(2018ABA104)
文摘[Objectives] This study was conducted to study early reproduction techniques of yellow catfish(Pelteobagrus fulvidraco) in Jianghan Plain. [Methods] Parents of P. fulvidraco were cultured by the methods of artificial temperature control and nutrition enhancement. [Results] After culture, the body weight, gonad weight, maturity coefficient and egg diameter of P. fulvidraco increased gradually. Up to April 30, the gonad weight of the female parents of P. fulvidraco cultured in greenhouses was significantly higher than that of the parents under natural conditions(P<0.05), 54% higher than that of the parents naturally cultured at the same period;the maturity coefficient of the parents cultured under strengthened conditions was also significantly higher than that of the parents under natural conditions at the same period(P<0.05);and the ovaries of the strengthened parents were orange yellow and full of eggs, and the number of eggs per fish was relatively high. In early May, the parents cultured under strengthened conditions were induced to spawn artificially. The average induced spawning rate and fertilization rate reached 86.7% and 71.6%, respectively, reaching the respective normal level. The gonad maturity of P. fulvidraco cultured under strengthened conditions was 15 d earlier than that under natural conditions, resulting in mass production of early-propagated larvae of P. fulvidraco. [Conclusions] In Jianghan plain area, artificial propagation can be achieved in early May by means of artificial temperature control and strengthened culture, which is 20 d ahead of natural conditions.
基金supported by the National Natural Science Foundation of China (31402307)the construction of public service platform for the evaluation of the value of aquatic feed and feed additives in Guangdong Province(2015A040404033)
文摘This experiment was conducted to investigate the effects of dietary arginine levels on growth performance, body composition, serum biochemical indices and resistance ability against ammonia-nitrogen stress in juvenile yellow catfish(Pelteobagrus fulvidraco). Five isonitrogenous and isolipidic diets(42%protein and 9% lipid) were formulated to contain graded levels of arginine(2.44%, 2.64%, 2.81%, 3.01% and3.23% of diet), by supplementing L-Arginine HCI. Seven hundred juvenile yellow catfish with an initial average body weight of 1.13 ± 0.02 g were randomly divided into 5 groups with 4 replicates of 35 fish each and each group was fed one of the diets. After 56 d feeding, fish were exposed to 100 mg/L of ammonia-nitrogen for 72 h. The results showed that weight gain(WG) and specific growth rate(SGR) in2.64% and 2.81% groups were significantly higher than those in 3.23% group(P < 0.05). The feed conversation ratio(FCR) in 2,64%, 2,81% and 3.01% groups was significantly decreased when compared with3,23% group. The protein efficiency ratio(PER) in 2.64% group was significantly higher than that in 2.44%and 3.23% groups(P < 0.05). The condition factor(CF) of fish was significantly higher in 2.81% group than that in 2,44% group(P < 0.05). Dietary arginine levels had no significant effect on hepatosomatic index(HSI), viscerosomatic index(VSI), and whole-body dry matter, crude protein, crude lipid, ash contents, as well as serum total protein(TP), triglyceride(TG), glucose(GLU), urea nitrogen(UN) contents and aspartate aminotransferase(AST), alanine aminotransferase(ALT) activities(P> 0.05). After the fish were challenged to ammonia-nitrogen for 72 h, their cumulative mortality rate in 2.81% group was significantly lower than that in 2.44% group(P < 0.05). The results suggested that dietary arginine level at 2.81%could optimize anti-ammonia-nitrogen stress ability of juvenile yellow catfish and a level of 3.23%arginine seemed to depress the growth performance of fish and decreased their tolerance to the ammonia-nitrogen stress under current study. A quadratic regression analysis based on WG indicated that the optimal dietary arginine requirement of juvenile yellow catfish was estimated to be 2.74% of the diet(6.45% of dietary protein) under current culture conditions.
基金The study was funded by National Natural Science Foundation of China(Grant nos.:31572605,31001101)Project of Innovative Group for Excellent Young Scientists in Universities of Hubei Province from Hubei Provincial Department of Education(T201933).
文摘In this study,three members of the Bmp family were cloned and characterized in yellow catfish Pelteobagrus fulvidraco,including Bmp2a,Bmp4 and Bmp9.The predicted amino acid sequences of P.fulvidraco Bmp2a,Bmp4 and Bmp9 showed the characteristic domains of the Bmp family,including an N-terminal signal peptide,Arg-X-XArg site,TGF-βfamily signature and seven conserved cysteines,indicating that function is likely to have been conserved during evolution.mRNAs of the three Bmp genes had a variable level of expression in tissues.Compared to the control diet,a high fat diet tended to down-regulate the mRNA expression of Bmp2a,Bmp4 and Bmp9 in mesenteric fat,liver and ovary,while it tended to up-regulate their mRNA levels in muscle and kidney.The responses to dietary lipid status and the potential role in lipid metabolism have not previously been reported and reinforces the idea of their multiple functions.Our findings provide the first data about the potential role of the Bmp family in lipid metabolism in teleost.
