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.
