The Analysis Of Mirna Which Regulate SCD1 Gene In Goose Fatty Liver

MicroRNAs (miRNAs) are a class of endogenous non-coding single-stranded RNA molecules of about 22nt, and it is widely present in many organisms,such as viruses, animals and plants, and by binding the 3’untranslated regions(3’UTR) of the target genes that can reduce translation from mRNA transcripts or lead to their degradation, make a negative regulation of the gene expression.SCDl is a kind of catalysis enzyme which is located in the endoplasmic reticulum, and it can limit the rate of synthesis the monounsaturated fatty acid in hepatocytes, transformed the palmitoyl and stearoyl-coenzyme A to palmitoleic acid and oleic acid respectively, these unsaturated fatty acids are important substrate to synthesis of various lipids, including triglycerides, phospholipids, cholesterol, wax esters and diglycerides. SCD1 has played a pivotal role in the fat synthesis and fatty acid oxidation in the liver.In this study, the expression of SCD1 gene in Anser liver and the miRNA which can regulate SCD1 were conducted. The main results are as follows:(1) During the overfeeding period, the liver weight and the liver-body-ratio were all gradually increased with the extension of overfeeding time, the average weight of liver was 124.5g in 70-day-age(overfed 0 day) and increased to 826.6g in 89-day-age(overfed 19 days); the average liver-body-ratio was 3.21% in 70-day-age and increased to 10.30% in 89-day-age. In this study, the expression of Landes SCD1 gene in various stages of overfeeding group an control group were detected by SYBR Green real-time PCR, the results show that the expression of SCD1 in overfeeding group were all higher than control group, and in overfed for 19 days (89-day-age),the SCD1 expression of overfeeding group was significantly higher than control group; We detected the level of palmitoleic acid, oleic acid, triglycerides and cholesterol in every stage of overfeeding period, and analyzed the correlation between the index and the SCD1 gene in every stages of overfeeding group, the expression of SCD1 is significantly positively correlated (P<0.01) with the content of oleic acid, cholesterol and VLDL, and were significantly correlated (P<0.05)with triglycerides.(2) We used the software combined the small-RNA sequencing results to screening three-miRNAs -miR-30b, miR-30a-5p and miR-10b, which may regulate the Landes SCD1 gene, and the expression of these three miRNA in control group were higher than in overfeeding group, which were opposite to the expression of SCD1.(3) We firstly cloned the Landes geese miR-30b and miR-30a-5p precursor sequences from Anser genome, and the homology of the precursors with chicken has reached 100%. After they were transfected into CHO cells, the transcriptional activity of genes was detected by dual luciferase reporter system. The results show that miR-30b and miR-30a-5p can regulate the expression of SCD1 gene. These revealed that miR-30b and miR-30a-5p might affect the lipid metabolism of goose by target SCD1 gene.