Preliminary Study On Regulation Of Lipid Metabolism Of Landes Geese Livers

An experiment was conducted research the candidate gene and early breeding projects of the fattty liver of Landes goose which had big markets. Performance of Landes geese fatty livers were controlled by lots of genes and regulation pathways. So the signal pathway and gene regulation network were the effect one to analysis the mechanism of geese fatty livers.The graphic model was established in order to grasp the regulation network of hepatic lipid homeostasis and discover the useful and important signal transduction because of complication of the fatty livers. The mRNA expression level of lipogenic genes involved the key signal pathway were detected by realtime PCR. Meanwhile, histological examination and analysis of fatty acids of the fatty livers were done used H & E stain and gas chromatography respectively. The signal transduction was proved by the trials and further study by the epigenetic method.Collect the data of molecular interaction from original research articles, reviews and molecular biological databank, and define the molecular entity as vertex, the relation between molecules as the edge in the graph, and mark the signaling direction with arrows, and then express the results with corresponding adjacency matrixes and obtain integrated adjacency matrix.By calculating the R=A+A2+A3+…+An, the accessible matrix was got. Then, we can induce the regulation relation between any molecules by accessible matrix. Through power the integrated adjacency matrix, the regulation relation between molecules upstream and downstream the molecules, as well as the crosstalk between signaling pathways were achieved. Based on the integrated adjacency matrix, the graph of regulation of molecular network related with lipid metabolism of Landes geese was produced using Matlab 6.0.Histological examination and analysis of fatty acids of the fatty liver were done used H & E stain and gas chromatography respectively. CT was used to investigate the fat deposition of living Landes goose. Compared to control group, overfeeding can increase the liver weight, liver index, serum ALT, TG, Che, HDL levels and change the positive ratio of liver and spleen to negative. Swelling of hepatocyte were observed within the cytoplasm of liver cells in goose treated with overfeeding compared to control. The values for the SFA, C18:2, C20:4, PUFA, SFA/UFA,,PUFA/UFA and PUFA/MUFA were significantly higher in control group than in overfeeding group. Higher values for MUFA, C18:1, UFA and MUFA/UFA in livers were found for goose in overfeeding group.The mRNA expression level of lipogenic genes were detected by realtime PCR. Compared to the control group, the mRNA expression level of ACCα, PPARα, aP2, LXRα, PPARγ, Spot14α, Spot14β, C/EBPα, C/EBPβand GH were increased in overfeeding group. The positive correlation between the transcriptional level of ACC a, LXR a and serum TG was observed (P<0.01). Significant positive correlations were also found between aP2, LXRα, PPARγin liver and liver/body weight.SREBP1c mRNA expression level in liver was decreased in overfeeding group compared to that of control. The significant negative correlations were observed between the expression of SREBP1c in liver and liver/body weight, serum TGThe overfed supplemented with T3 markedly increased the liver weight, liver/body weight, compared with control and overfed diet. Plasma levels of Che, HDL and LDL were higher in control group than in the overfed supplemented with T3 geese. T3 significantly increased the number of fatty droplets and exhibited bigger lipid droplets. Geese fed diets supplemented with T3 had higher concentration of UFA in liver, compared to control and overfeeding group. The effect of T3 on the UFA content can be reversed by betaine.The effect of T3 on ACC a and aP2 gene expression were also determined in Landes geese livers using real time PCR. ACC a and aP2 mRNA expression were significantly increased in T3-fed geese compared with control and overfed group. The transcriptional level of ACC a and aP2 gene were reversed by betaine significantly. Compared to the overfeeding group, the mRNA expression level of PPARγ,PPARα,C/EBPβ,LXRαand GH were decreased in T3 treatment group. The significant negative correlations were observed between the expression of SREBPlc in liver and liver/body weight, serum TG However, the significant correlations were observed between the expression of ACC a and Spot14αin liver and serum TG content.The geese fed the betaine diet showed increased liver weight and decreased abdominal adipose weight compared with the control diet and overfeeding group. Betaine treatment also increased body weighy (BW) (P<0.01) and increased serum triglyceride (TG), Che and low density lipoproteins (LDL) compared with the control group and no increase in these parameters relative to the overfeeding group. Diffuse yellow lesions and swelling of hepatocytes were observed in the betaine-treated group, which also had significantly decreased macrovesicular or microvesicular steatosis. Geese treated with betaine had no effect on the fatty acids profile in the livers compared with the control diet.C/EBPβ,PPARα,Spot14β,PPARγand LXRαmRNA expression were significantly decreased in betaine-fed geese compared with overfeeding group. The transcriptional level of Spot14αwas increased by the diets supplemented with betaine.We cloned the cDNA sequence of goose Spot14α(EU710582). The gene was predicted to encode a peptide of 128 amino acids, which has 87% and 84% sequence identities at the cDNA and amino acid levels, respectively, with the duck counterparts. High percentage of G and C nucleotides were found in exon and 3'untranslated region of the goose Spot 14 a cDNA.A novel frameshift mutation that leads to a damaged leucine zipper motif was observed at nucleotide position 399～400. This can influence the homodimerization of Spot14α, probably resulting in dysfunction in the Spot 14 family in vivo.We performed sodium bisulfite sequencing of individual alleles of this region (between+374 and -8 base pairs relative to the transcription start site), which contains 33 CpG dinucleotides of Spot14α. In the overfed group and T3 treatment group, the average methylation at the 33 CpGs sites were 87.9% and 94% in contrast to 69.6% in control group respectively. The significant differences were obsereved among the three groups. Compared to the overfeeding group, betaine treatment (82.6%) of the average methylation at these CpGs sites can not achieve the statistic significant change. But the level of methylation in this region was decreased.The result of this article showed that T3 and betaine treatment can make the liver weight of Landes geese increased. Meanwhile, no T3 was found in the fatty liver in the condition of adaptive time and suitable dose. The result might be significitant for the production of Landes geese fatty liver.