The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth g...The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.展开更多
Adult pharyngeal teeth in Mylopharyngodon piceus are molariform. Based on SEM observations ofthe developing teeth, this paper describes the morphological diversification of pharyngeal teeth in M.piceus. The larval and...Adult pharyngeal teeth in Mylopharyngodon piceus are molariform. Based on SEM observations ofthe developing teeth, this paper describes the morphological diversification of pharyngeal teeth in M.piceus. The larval and juvenile teeth are changed from conical to adult molariform teeth through sevenstages. Comparisons are made between each stage and corresponding types in some species of differentsubfamilies in Cyprinidae. It is considered that the ontogenetic resemblances of the pharyngeal teehbear relationship to the phylogeny of cyprinids.展开更多
As one of the world's“staple”freshwater fish species,black carp(Mylopharyngodon piceus)faces critical challenges from bacterial diseases.Toll-like receptors(TLRs),serving as frontline pathogen sensors,play cruci...As one of the world's“staple”freshwater fish species,black carp(Mylopharyngodon piceus)faces critical challenges from bacterial diseases.Toll-like receptors(TLRs),serving as frontline pathogen sensors,play crucial roles in antibacterial defense.This study systematically identified 21 TLR members through genomic analysis,revealing their uneven distribution across 11 chromosomes with evolutionarily conserved synteny in cyprinids.Phylogenetic reconstruction,sequence,and selection pressure assessment demonstrated that TLR subfamilies maintain structural and sequence conservation and undergo strong purifying selection.Tissue-specific transcriptome profiling showed broad TLR expression patterns,with several members exhibiting significant differential expression in Aeromonas hydrophila-resistant populations.Functional validation focused on the most prominently altered MpTLR1 revealed that its knockdown increased infection-induced mortality and exacerbated histopathological damage.Mechanistic investigations demonstrated that MpTLR1 suppression significantly impaired antioxidant enzyme activities(antioxidant capacity and superoxide dismutase),complement C3 levels and lysozyme activity,while downregulating mRNA expression levels of pro-inflammatory cytokines(TNF-α,IFN-γ2,and IL-6),complement C3,and antimicrobial peptides(hepcidin and liver-expressed antimicrobial peptide 2).Our work provides a systematic characterization of black carp TLRs and establishes MpTLR1's pivotal role in bacterial immunity through coordinating antioxidant defense and inflammatory responses.These findings offer insights for breeding A.hydrophila-resistant black carp populations.展开更多
Black carp(Mylopharyngodon piceus)is an important freshwater fish species in China,and fishery resources have been severely depleted for decades.Understanding the population genetic background is a prerequisite for co...Black carp(Mylopharyngodon piceus)is an important freshwater fish species in China,and fishery resources have been severely depleted for decades.Understanding the population genetic background is a prerequisite for conservation of black carp genetic resources.Complete mitogenome was analyzed for the first time to study the population genetic diversity and structure of black carp across China.The complete mitochondrial genomes obtained from six wild and three farmed populations ranged from 16,598 to 16,614 base pairs.Black carp populations across China are characterized by moderate to high genetic differentiation(0.08≤FST≤0.55,P<0.05),with a low overall degree of gene flow(0.34≤Nm≤2.61)individuals per generation.The nucleotide diversity(Pi)ranged from 0.0010 to 0.0024 and the average number of pairwise nucleotide differences(K)ranged from 17.4 to 40.2,with the minimum Pi and K values(0.0010 and 17.4)observed in the Foshan population.Compared to farmed populations,wild populations exhibited high average genetic diversity.Neighbor-joining phylogenetic reconstructions revealed two main genetic lineages,one represented by wild populations from the middle reaches of the Yangtze River and the other by populations from the lower reaches of the Yangtze River and farmed populations.The results of Tajima's D and Fu's F neutrality tests and the nucleotide mismatch distribution indicated that wild populations expanded rapidly after undergoing a historic genetic bottleneck.Demographic decline over recent generations has resulted in a bottleneck effect upon black carp populations and genetic connectivity across its distribution has become limited.Poorly designed artificial propagation,long-term inbreeding and random genetic drift probably were the main causes of low genetic diversity in cultured populations.Our results provide baseline information crucial for conservation of black carp genetic resources in China.展开更多
Both in nature and in aquaculture,fish may experience periods of food scarcity or hunger.The metabolic regulation of fish when nutritional state changes is a complex process that involves many factors.To study glucose...Both in nature and in aquaculture,fish may experience periods of food scarcity or hunger.The metabolic regulation of fish when nutritional state changes is a complex process that involves many factors.To study glucose metabolism adaptability during fasting and re-feeding in the black carp(Mylopharyngodon piceus),we measured changes in some biochemical indicators related to glucose metabolism.Five fish were sampled on days 0,1,3,5,and 10 of fasting(F,S1,S3,S5,and S10,respectively)and days 1,3,and 5 of re-feeding(RF1,RF3,and RF5,respectively).The serum glucose concentration decreased significantly at S1,reached the lowest point at S10,and increased significantly at RF1(P<0.05).The concentration of liver glycogen decreased significantly at S1 and reached the lowest level at S3,whereas the muscle glycogen level decreased significantly at S5 and reached the lowest value at S10(P<0.05).Both liver and muscle glycogen levels returned to the pre-fasting level at RF5(P<0.05).Regarding glycolysis,the concentrations of pyruvate kinase(PK)and hexokinase(HK)decreased significantly at S5 and increased significantly at RF5 and RF1,respectively(P<0.05).The concentrations of glucokinase(GCK)and insulin decreased significantly at S1 and increased significantly at RF1 and RF3,respectively(P<0.05).The mRNA expression levels of liver GCK and glucose transporter 2(GLUT2)decreased significantly at S1 and increased significantly at RF1 and RF5,respectively(P<0.05).As for gluconeogenesis,the concentration of glucose-6-phosphatase(G6PC)increased significantly at S1 and decreased significantly at RF1(P<0.05).The concentrations of glucagon and glucocorticoid(GC)increased significantly at S3 and significantly decreased at RF1 and RF5,respectively(P<0.05).The mRNA expression levels of liver G6PC and phosphoenolpyruvate carboxykinase(PEPCK)increased significantly at S3 and S1,and both decreased significantly at RF1(P<0.05).These results indicate that coordination between glycolysis and gluconeogenesis might be crucial for glucose homeostasis during fasting and re-feeding in the black carp.展开更多
In this paper,we studied the structure,expression and function of black carp insulin gene.The complete Mylopharyngodon piceus insulin(Mp-Ins)gene is 1,965 bp long and includes a 1,499 bp 5ʹ-untranslated region(UTR),a ...In this paper,we studied the structure,expression and function of black carp insulin gene.The complete Mylopharyngodon piceus insulin(Mp-Ins)gene is 1,965 bp long and includes a 1,499 bp 5ʹ-untranslated region(UTR),a 139 bp 3′-UTR with a poly(A)tail,and an open reading frame(ORF)of 327 bp.The predicted molecular weight of the recombinant Mp-Ins(rMp-Ins)protein is 11.87 kDa.The mRNA expression of Mp-Ins is upregulated in the brain and liver.After the injection of rMp-Ins,Mp-Ins mRNA transcript abundance was significantly upregulated in the liver.The rMp-Ins protein could inhibit the concentration of glycogen phosphorylase(GP),growth hormone(GH),fatty acid synthase(FAS),and insulin-like growth factors-1(IGF-1),and it also significantly increased the concentration of PI3K.Additionally,the injection of rMp-Ins did not have a significant impact on the glucose-6-phosphatase(G6Pase)content in blood.In situ hybridization results showed that the positive signal of the Mp-Ins gene was mainly concentrated in the cell nucleus of brain tissue and the cell membrane of liver tissue and muscle tissue.Together,these results demonstrated that Mp-Ins plays an important role in growth and metabolism in M.piceus.展开更多
基金This project was funded by the International Cooperation of japan-Chinathe National Natural Science Foundation of China
文摘The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.
基金This project was funded by the interstional Cooperation of Japan-China and the National Natural Science foundation of China.
文摘Adult pharyngeal teeth in Mylopharyngodon piceus are molariform. Based on SEM observations ofthe developing teeth, this paper describes the morphological diversification of pharyngeal teeth in M.piceus. The larval and juvenile teeth are changed from conical to adult molariform teeth through sevenstages. Comparisons are made between each stage and corresponding types in some species of differentsubfamilies in Cyprinidae. It is considered that the ontogenetic resemblances of the pharyngeal teehbear relationship to the phylogeny of cyprinids.
基金supported by National Natural Science Foundation of China(32373164).
文摘As one of the world's“staple”freshwater fish species,black carp(Mylopharyngodon piceus)faces critical challenges from bacterial diseases.Toll-like receptors(TLRs),serving as frontline pathogen sensors,play crucial roles in antibacterial defense.This study systematically identified 21 TLR members through genomic analysis,revealing their uneven distribution across 11 chromosomes with evolutionarily conserved synteny in cyprinids.Phylogenetic reconstruction,sequence,and selection pressure assessment demonstrated that TLR subfamilies maintain structural and sequence conservation and undergo strong purifying selection.Tissue-specific transcriptome profiling showed broad TLR expression patterns,with several members exhibiting significant differential expression in Aeromonas hydrophila-resistant populations.Functional validation focused on the most prominently altered MpTLR1 revealed that its knockdown increased infection-induced mortality and exacerbated histopathological damage.Mechanistic investigations demonstrated that MpTLR1 suppression significantly impaired antioxidant enzyme activities(antioxidant capacity and superoxide dismutase),complement C3 levels and lysozyme activity,while downregulating mRNA expression levels of pro-inflammatory cytokines(TNF-α,IFN-γ2,and IL-6),complement C3,and antimicrobial peptides(hepcidin and liver-expressed antimicrobial peptide 2).Our work provides a systematic characterization of black carp TLRs and establishes MpTLR1's pivotal role in bacterial immunity through coordinating antioxidant defense and inflammatory responses.These findings offer insights for breeding A.hydrophila-resistant black carp populations.
基金the Earmarked Fund for the Agriculture Research System of China(CARS-45-04).
文摘Black carp(Mylopharyngodon piceus)is an important freshwater fish species in China,and fishery resources have been severely depleted for decades.Understanding the population genetic background is a prerequisite for conservation of black carp genetic resources.Complete mitogenome was analyzed for the first time to study the population genetic diversity and structure of black carp across China.The complete mitochondrial genomes obtained from six wild and three farmed populations ranged from 16,598 to 16,614 base pairs.Black carp populations across China are characterized by moderate to high genetic differentiation(0.08≤FST≤0.55,P<0.05),with a low overall degree of gene flow(0.34≤Nm≤2.61)individuals per generation.The nucleotide diversity(Pi)ranged from 0.0010 to 0.0024 and the average number of pairwise nucleotide differences(K)ranged from 17.4 to 40.2,with the minimum Pi and K values(0.0010 and 17.4)observed in the Foshan population.Compared to farmed populations,wild populations exhibited high average genetic diversity.Neighbor-joining phylogenetic reconstructions revealed two main genetic lineages,one represented by wild populations from the middle reaches of the Yangtze River and the other by populations from the lower reaches of the Yangtze River and farmed populations.The results of Tajima's D and Fu's F neutrality tests and the nucleotide mismatch distribution indicated that wild populations expanded rapidly after undergoing a historic genetic bottleneck.Demographic decline over recent generations has resulted in a bottleneck effect upon black carp populations and genetic connectivity across its distribution has become limited.Poorly designed artificial propagation,long-term inbreeding and random genetic drift probably were the main causes of low genetic diversity in cultured populations.Our results provide baseline information crucial for conservation of black carp genetic resources in China.
基金supported by China Agriculture Research System of MOF and MARA(CARS-45-03).
文摘Both in nature and in aquaculture,fish may experience periods of food scarcity or hunger.The metabolic regulation of fish when nutritional state changes is a complex process that involves many factors.To study glucose metabolism adaptability during fasting and re-feeding in the black carp(Mylopharyngodon piceus),we measured changes in some biochemical indicators related to glucose metabolism.Five fish were sampled on days 0,1,3,5,and 10 of fasting(F,S1,S3,S5,and S10,respectively)and days 1,3,and 5 of re-feeding(RF1,RF3,and RF5,respectively).The serum glucose concentration decreased significantly at S1,reached the lowest point at S10,and increased significantly at RF1(P<0.05).The concentration of liver glycogen decreased significantly at S1 and reached the lowest level at S3,whereas the muscle glycogen level decreased significantly at S5 and reached the lowest value at S10(P<0.05).Both liver and muscle glycogen levels returned to the pre-fasting level at RF5(P<0.05).Regarding glycolysis,the concentrations of pyruvate kinase(PK)and hexokinase(HK)decreased significantly at S5 and increased significantly at RF5 and RF1,respectively(P<0.05).The concentrations of glucokinase(GCK)and insulin decreased significantly at S1 and increased significantly at RF1 and RF3,respectively(P<0.05).The mRNA expression levels of liver GCK and glucose transporter 2(GLUT2)decreased significantly at S1 and increased significantly at RF1 and RF5,respectively(P<0.05).As for gluconeogenesis,the concentration of glucose-6-phosphatase(G6PC)increased significantly at S1 and decreased significantly at RF1(P<0.05).The concentrations of glucagon and glucocorticoid(GC)increased significantly at S3 and significantly decreased at RF1 and RF5,respectively(P<0.05).The mRNA expression levels of liver G6PC and phosphoenolpyruvate carboxykinase(PEPCK)increased significantly at S3 and S1,and both decreased significantly at RF1(P<0.05).These results indicate that coordination between glycolysis and gluconeogenesis might be crucial for glucose homeostasis during fasting and re-feeding in the black carp.
基金This research was supported by China’s Agricultural Research System(CARS-45-03).
文摘In this paper,we studied the structure,expression and function of black carp insulin gene.The complete Mylopharyngodon piceus insulin(Mp-Ins)gene is 1,965 bp long and includes a 1,499 bp 5ʹ-untranslated region(UTR),a 139 bp 3′-UTR with a poly(A)tail,and an open reading frame(ORF)of 327 bp.The predicted molecular weight of the recombinant Mp-Ins(rMp-Ins)protein is 11.87 kDa.The mRNA expression of Mp-Ins is upregulated in the brain and liver.After the injection of rMp-Ins,Mp-Ins mRNA transcript abundance was significantly upregulated in the liver.The rMp-Ins protein could inhibit the concentration of glycogen phosphorylase(GP),growth hormone(GH),fatty acid synthase(FAS),and insulin-like growth factors-1(IGF-1),and it also significantly increased the concentration of PI3K.Additionally,the injection of rMp-Ins did not have a significant impact on the glucose-6-phosphatase(G6Pase)content in blood.In situ hybridization results showed that the positive signal of the Mp-Ins gene was mainly concentrated in the cell nucleus of brain tissue and the cell membrane of liver tissue and muscle tissue.Together,these results demonstrated that Mp-Ins plays an important role in growth and metabolism in M.piceus.
