Glass catfish(Kryptopterus vitreolus)are notable in the aquarium trade for their highly transparent body pattern.This transparency is due to the loss of most reflective iridophores and light-absorbing melanophores in ...Glass catfish(Kryptopterus vitreolus)are notable in the aquarium trade for their highly transparent body pattern.This transparency is due to the loss of most reflective iridophores and light-absorbing melanophores in the main body,although certain black and silver pigments remain in the face and head.To date,however,the molecular mechanisms underlying this transparent phenotype remain largely unknown.To explore the genetic basis of this transparency,we constructed a chromosome-level haplotypic genome assembly for the glass catfish,encompassing 32 chromosomes and 23344 protein-coding genes,using PacBio and Hi-C sequencing technologies and standard assembly and annotation pipelines.Analysis revealed a premature stop codon in the putative albinism-related tyrp1b gene,encoding tyrosinase-related protein 1,rendering it a nonfunctional pseudogene.Notably,a synteny comparison with over 30 other fish species identified the loss of the endothelin-3(edn3b)gene in the glass catfish genome.To investigate the role of edn3b,we generated edn3b^(−/−)mutant zebrafish,which exhibited a remarkable reduction in black pigments in body surface stripes compared to wild-type zebrafish.These findings indicate that edn3b loss contributes to the transparent phenotype of the glass catfish.Our high-quality chromosome-scale genome assembly and identification of key genes provide important molecular insights into the transparent phenotype of glass catfish.These findings not only enhance our understanding of the molecular mechanisms underlying transparency in glass catfish,but also offer a valuable genetic resource for further research on pigmentation in various animal species.展开更多
Poyang Lake catfish （Silurus asotus Linnaeus） is native to Poyang Lake Basin. Artificial propagation of Poyang Lake catfish was carried out by using artificial insemination. Under water temperature of 18-26 ℃, embr...Poyang Lake catfish （Silurus asotus Linnaeus） is native to Poyang Lake Basin. Artificial propagation of Poyang Lake catfish was carried out by using artificial insemination. Under water temperature of 18-26 ℃, embryonic development of Poyang Lake catfish in impounded water was observed and recorded in detail. Embryonic development of Poyang Lake catfish encountered seven stages, and it last- ed for 47.08 h from the fertilized egg stage to the stripping stage. The hatching time of Silurus meridionalis Chen was shortest, followed by that of Poyang Lake catfish, and the hatching time of Pelteobagrus vachelli was longest.展开更多
To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divid...To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.展开更多
Background:Muscle is the complex and heterogeneous tissue,which comprises the primary edible part of the trunk of fish and mammals.Previous studies have shown that dietary isoleucine(Ile)exerts beneficial effects on g...Background:Muscle is the complex and heterogeneous tissue,which comprises the primary edible part of the trunk of fish and mammals.Previous studies have shown that dietary isoleucine(Ile)exerts beneficial effects on growth in aquatic animals.However,there were limited studies regarding the benefits of Ile on fish muscle and their effects on flesh quality and muscle growth.Thus,this study was conducted to explore whether dietary Ile had affected flesh quality and muscle growth in hybrid bagrid catfish(Pelteobagrus vachelli♀×Leiocassis longirostris♂).Methods:A total of 630 hybrid fish,with an initial average body weight of 33.11±0.09 g,were randomly allotted into seven experimental groups with three replicates each,and respectively fed seven diets with 5.0,7.5,10.0,12.5,15.0,17.5,and 20.0 g Ile/kg diets for 8 weeks.Results:In the present study,we demonstrated that Ile significantly:(1)increased muscle protein and lipid contents and the frequency distribution of myofibers with≤20μm and≥50μm of diameter;(2)improved pH value,shear force,cathepsin B and L activities,hydroxyproline content,resilience,cohesiveness,and decreased cooking loss,lactate content,hardness,springiness,gumminess,and chewiness;(3)decreased reactive oxygen species(ROS),malondialdehyde(MDA),and protein carbonyl(PC)contents,GCLC and Keap1 mRNA levels,and up-regulated CuZnSOD,CAT,GPX1a,GST,and Nrf2 mRNA levels;(4)up-regulated the insulin-like growth factor 1,2(IGF-1,IGF-2),insulin-like growth factor 1 receptor(IGF-1R),proliferating cell nuclear antigen(PCNA),Myf5,Myod,Myog,Mrf4,and MyHC mRNA levels,and decreased MSTN mRNAlevel;(5)increased muscle protein deposition by activating AKT-TOR-S6K1 and AKT-FOXO3a signaling pathways.Conclusion:These results revealed that dietary Ile improved flesh quality,which might be due to increasing nutritional content,physicochemical,texture parameters,and antioxidant ability;promoting muscle growth by affecting myocytes hyperplasia and hypertrophy,and muscle protein deposition associated with protein synthesis and degradation signaling pathways.Finally,the quadratic regression analysis of chewiness,ROS,and protein contents against dietary Ile levels suggested that the optimal dietary Ile levels for hybrid bagrid catfish was estimated to be 14.19,12.36,and 12.78 g/kg diet,corresponding to 36.59,31.87,and 32.96 g/kg dietary protein,respectively.展开更多
The influence of different cooking and smoking methods (boiling, frying, frying + boiling, hot and cold smoking) on oxidation and fatty acid composition of catfish (Arius maculatus) commercialized on the Wouri river c...The influence of different cooking and smoking methods (boiling, frying, frying + boiling, hot and cold smoking) on oxidation and fatty acid composition of catfish (Arius maculatus) commercialized on the Wouri river coast was evaluated including commonly used analytical indexes (peroxide and acid values)and physical analysis by Fourier transform infrared (FTIR) spectroscopy. The mean moisture, protein, ash and fat contents of raw fish were 75.88 ± 0.55;64.24 ± 0.14;10.98 ± 0.31 and 23.02 ± 0.88 respectively. All these treatments provoke the modification of the quality indexes. Lipid deterioration, thermolysis and lipid oxidation occurred throughout the treatment. Peroxide value decreased for all cooked and smoked catfish, while free fatty acids of smoked sample increased. The FTIR applied to evaluate lipid oxidation in extracted lipid clearly provided a better picture of the oxidation progress and led to a similar conclusion with chemical analysis. Boiled, bleaching hot and bleaching cold smoking were found to be the suitable treatment methods for catfish because they gave it a high nutritive value compared to other smoking methods.展开更多
基金supported by the National Key Research and Development Program of China(2022YFE0139700,2023YFE0205100)Key Laboratory of Tropical and Subtropical Fishery Resources Application and Cultivation,Ministry of Agriculture and Rural Affairs,Pearl River Fisheries Research Institute,Chinese Academy of Fishery Sciences(20220202)+3 种基金Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Team(2023KJ150)China-ASEAN Maritime Cooperation Fund(CAMC-2018F)National Freshwater Genetic Resource Center(FGRC18537)Guangdong Rural Revitalization Strategy Special Provincial Organization and Implementation Project Funds(2022-SBH-00-001)。
文摘Glass catfish(Kryptopterus vitreolus)are notable in the aquarium trade for their highly transparent body pattern.This transparency is due to the loss of most reflective iridophores and light-absorbing melanophores in the main body,although certain black and silver pigments remain in the face and head.To date,however,the molecular mechanisms underlying this transparent phenotype remain largely unknown.To explore the genetic basis of this transparency,we constructed a chromosome-level haplotypic genome assembly for the glass catfish,encompassing 32 chromosomes and 23344 protein-coding genes,using PacBio and Hi-C sequencing technologies and standard assembly and annotation pipelines.Analysis revealed a premature stop codon in the putative albinism-related tyrp1b gene,encoding tyrosinase-related protein 1,rendering it a nonfunctional pseudogene.Notably,a synteny comparison with over 30 other fish species identified the loss of the endothelin-3(edn3b)gene in the glass catfish genome.To investigate the role of edn3b,we generated edn3b^(−/−)mutant zebrafish,which exhibited a remarkable reduction in black pigments in body surface stripes compared to wild-type zebrafish.These findings indicate that edn3b loss contributes to the transparent phenotype of the glass catfish.Our high-quality chromosome-scale genome assembly and identification of key genes provide important molecular insights into the transparent phenotype of glass catfish.These findings not only enhance our understanding of the molecular mechanisms underlying transparency in glass catfish,but also offer a valuable genetic resource for further research on pigmentation in various animal species.
基金Supported by Jiangxi Province Science and Technology Support Program(20121BBF60037)Research on Key Propagation-culturing Technology of Silurus asotus Linnaeus~~
文摘Poyang Lake catfish （Silurus asotus Linnaeus） is native to Poyang Lake Basin. Artificial propagation of Poyang Lake catfish was carried out by using artificial insemination. Under water temperature of 18-26 ℃, embryonic development of Poyang Lake catfish in impounded water was observed and recorded in detail. Embryonic development of Poyang Lake catfish encountered seven stages, and it last- ed for 47.08 h from the fertilized egg stage to the stripping stage. The hatching time of Silurus meridionalis Chen was shortest, followed by that of Poyang Lake catfish, and the hatching time of Pelteobagrus vachelli was longest.
基金supported by the Special Founda-tion for Young Leaders Fellowship in the Sichuan Agri-cultural University, China (45078925-5).
文摘To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.
基金supported by National Key R&D Program of China(2019YFD0900200)the Applied Basic Research Programs of ScienceTechnology Commission Foundation of Sichuan Province,China(2015JY0067).
文摘Background:Muscle is the complex and heterogeneous tissue,which comprises the primary edible part of the trunk of fish and mammals.Previous studies have shown that dietary isoleucine(Ile)exerts beneficial effects on growth in aquatic animals.However,there were limited studies regarding the benefits of Ile on fish muscle and their effects on flesh quality and muscle growth.Thus,this study was conducted to explore whether dietary Ile had affected flesh quality and muscle growth in hybrid bagrid catfish(Pelteobagrus vachelli♀×Leiocassis longirostris♂).Methods:A total of 630 hybrid fish,with an initial average body weight of 33.11±0.09 g,were randomly allotted into seven experimental groups with three replicates each,and respectively fed seven diets with 5.0,7.5,10.0,12.5,15.0,17.5,and 20.0 g Ile/kg diets for 8 weeks.Results:In the present study,we demonstrated that Ile significantly:(1)increased muscle protein and lipid contents and the frequency distribution of myofibers with≤20μm and≥50μm of diameter;(2)improved pH value,shear force,cathepsin B and L activities,hydroxyproline content,resilience,cohesiveness,and decreased cooking loss,lactate content,hardness,springiness,gumminess,and chewiness;(3)decreased reactive oxygen species(ROS),malondialdehyde(MDA),and protein carbonyl(PC)contents,GCLC and Keap1 mRNA levels,and up-regulated CuZnSOD,CAT,GPX1a,GST,and Nrf2 mRNA levels;(4)up-regulated the insulin-like growth factor 1,2(IGF-1,IGF-2),insulin-like growth factor 1 receptor(IGF-1R),proliferating cell nuclear antigen(PCNA),Myf5,Myod,Myog,Mrf4,and MyHC mRNA levels,and decreased MSTN mRNAlevel;(5)increased muscle protein deposition by activating AKT-TOR-S6K1 and AKT-FOXO3a signaling pathways.Conclusion:These results revealed that dietary Ile improved flesh quality,which might be due to increasing nutritional content,physicochemical,texture parameters,and antioxidant ability;promoting muscle growth by affecting myocytes hyperplasia and hypertrophy,and muscle protein deposition associated with protein synthesis and degradation signaling pathways.Finally,the quadratic regression analysis of chewiness,ROS,and protein contents against dietary Ile levels suggested that the optimal dietary Ile levels for hybrid bagrid catfish was estimated to be 14.19,12.36,and 12.78 g/kg diet,corresponding to 36.59,31.87,and 32.96 g/kg dietary protein,respectively.
文摘The influence of different cooking and smoking methods (boiling, frying, frying + boiling, hot and cold smoking) on oxidation and fatty acid composition of catfish (Arius maculatus) commercialized on the Wouri river coast was evaluated including commonly used analytical indexes (peroxide and acid values)and physical analysis by Fourier transform infrared (FTIR) spectroscopy. The mean moisture, protein, ash and fat contents of raw fish were 75.88 ± 0.55;64.24 ± 0.14;10.98 ± 0.31 and 23.02 ± 0.88 respectively. All these treatments provoke the modification of the quality indexes. Lipid deterioration, thermolysis and lipid oxidation occurred throughout the treatment. Peroxide value decreased for all cooked and smoked catfish, while free fatty acids of smoked sample increased. The FTIR applied to evaluate lipid oxidation in extracted lipid clearly provided a better picture of the oxidation progress and led to a similar conclusion with chemical analysis. Boiled, bleaching hot and bleaching cold smoking were found to be the suitable treatment methods for catfish because they gave it a high nutritive value compared to other smoking methods.
