| Changing the energy level of an animal’s diet can affect the digestion,absorption and utilization of nutrients by the animal’s body,thereby changing the body’s growth performance.In the current intensive breeding environment,in order to pursue higher economic benefits,some producers will increase the energy level of the diet so that the animals have better production performance,but this may break the energy balance of the liver to a certain extent and cause problems such as lipid metabolism disorders.It is reported that SREBP-1c,AMPK,SIRT1,Apo B and DGAT1 and other genes play an important role in regulating the body’s nutrient metabolism,but it is still unclear whether they mediate abnormal energy and cause metabolic disorders in the body.Therefore,this study took Hu sheep under different growth and development stages and different energy feeding conditions as the research object to study the expression changes of genes that regulate energy metabolism and lipid metabolism in the liver of Hu sheep.While enriching the research of ruminant liver physiology,it also provides a certain theoretical basis for the scientific feeding and management of large-scale sheep farms.This test is divided into the following three parts:Experiment 1.Changes of liver energy metabolism and lipid metabolism related gene expression during Hu Sheep growth and developmentMale Hu sheep aged 3 months,8 months and 24 months were selected as the research objects,and they were divided into 3 groups with 4 animals in each group.H&E staining,immunohistochemistry,fluorescent quantitative PCR and western blotting were used to analyze the changes in liver tissue morphology,cell proliferation,energy metabolism and lipid metabolism-related genes expression changes in the liver tissues of Hu sheep at different ages.The results showed that: Energy metabolism-related proteins LKB1,m TOR,PGC-1α,SIRT1,SREBP-1c,LXRα and DGAT1 are mainly expressed in the liver cytoplasm.With the growth of liver tissue,compared with 8-month-old Hu sheep liver tissue,the m RNA expression levels of PCNA,AMPK,m TOR,PGC-1α,SREBP-1c and LXRα at the age of 3 and 24 months were significantly reduced(P < 0.05);Compared with 8-month-old Hu sheep liver tissue,the expression levels of LKB1,Fox O1 and ACADL in the 3-month-old group were significantly lower(P <0.05);compared with 8-month-old Hu sheep liver tissue,the 24-month-old group SIRT1 The expression levels of,Apo B and DGAT1 were significantly reduced(P <0.05).Compared with 8-month-old Hu sheep liver tissue,the PCNA protein expression level of 3-month-old group and 24-month-old group was significantly lower(P <0.05);Compared with 8-month-old Hu sheep liver tissue,the protein expression levels of LKB1 and DGAT1 in the 24-month-old group were significantly lower(P <0.05).In summary,in the growth process of Hu sheep,the energy and lipid metabolism related genes in liver tissue and the cell proliferation gene PCNA are expressed in time and space,which may be closely related to the growth of liver tissue and homeostasis,and specific regulation The mechanism needs to be further studied.Experiment 2.The effect of high-energy feeding on energy metabolism in the liver tissue of Hu sheepIn this experiment,36 three-month-old Hu sheep males with similar body weights were used as the research object.The pre-feeding period was 14 days and the formal period was 70 days.They were randomly divided into two dietary energy level groups: normal feeding group and high-energy feeding group,3 repetitions per group,6 repetitions per group.They were slaughtered after 12 hours of fasting,and liver tissues were collected for testing.Through H&E staining,immunohistochemistry,fluorescent quantitative PCR and western blotting,the effects of high-energy feeding on liver tissue morphology changes,cell proliferation and energy metabolism-related gene expression were studied.The results showed that in the liver tissues of Hu sheep that cannot be fed with dietary energy,PCNA protein is mainly expressed in the nucleus of liver cells;the expression of energy metabolismrelated genes LKB1,m TOR,PGC-1α protein is mainly located in the liver cytoplasm.Highenergy feeding significantly increased the expression of PCNA m RNA and protein in liver tissue(P <0.05);significantly reduced the expression of LKB1 and AMPK m RNA and protein in liver tissue(P <0.05);significantly reduced PGC-1ɑ and Sirt1 in liver tissue The protein expression level of m TOR(P <0.05);the m RNA expression level of m TOR has a rising trend;The m RNA expression levels of m TOR,Fox O1,PGC-1α,and SIRT1 were not significantly different between the high-energy feeding group and the normal feeding group.In summary,under high-energy feeding conditions,the LKB-1-AMPK-m TOR signaling pathway and other energy metabolism-related genes may be activated,and the expression level of the cell proliferation gene PCNA can be increased,thereby affecting liver tissue growth and internal environment stability.State and liver energy metabolism level.Experiment 3.The effect of high-energy feeding on the lipid metabolism of the liver tissue of Hu sheepThe test materials are the same as test two.Through immunohistochemistry,fluorescence quantitative PCR and western blotting,the effects of high-energy feeding on the expression of genes related to lipid metabolism in the liver of Hu sheep were studied.The results showed that in the liver tissues of Hu sheep,the expression of SREBP-1c,LXRα and DGAT1 proteins were mainly located in the liver cytoplasm.High-energy feeding significantly increased the expression of SREBP-1c,LXRα and Apo B m RNA in liver tissue(P <0.05),and the expression of ACADL and DGAT1 m RNA had an upward trend;significantly increased the expression of SREBP-1c protein in liver tissue(P <0.05)0.05),and LXRα and DGAT1 have a rising trend.In summary,under high-energy feeding conditions,lipid metabolism-related genes may be activated,which affects the level of liver lipid metabolism,the amount of fat deposition in liver tissue,and the homeostasis. |
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