The Function Of CREB Gene In Milk Lipid Metabolism In Goat Mammary Epithelial Cells

Goat milk has balanced nutritional value,rich in milk fat and unsaturated fatty acids.These nutrients have a significant therapeutic effect in health care and their content is largely determined by external conditions such as the diet structure of the animal.However,the raising scale and management mode of goats are at a low level in China,which has become the main bottleneck to restrict the improvement of goat production performance and dairy quality.In recent years,improving the content of beneficial fatty acids in goat milk by methods of molecular biology has increassingly become an important approach in modern goat breeding.c AMP response element binding protein(CREB)is a significant protein in the nucleus.CREB can activate and regulate the transcriptional activity of lipid metabolism-related target genes through self-phosphorylation and dephosphorylation.At present,there are few studies on the regulation mechanism of milk fat metabolism in ruminants.This study cloned the region of CDS of CREB gene from dairy goat mammary gland tissue and built adenovirus expression vector and si RNA targetted the CREB gene.Detecting the gene expression level of milk fat metabolism,cell within the total triglyceride content,unsaturated fatty acid content and saturation index,in order to further reveal CREB in goat mammary epithelial cells in milk fat metabolism function and improve the dairy goats qualitative theory basis.The main research results are as follows:1.The CDS region of CREB gene was 984 bp(Gen Bank No.MK158073.1),encoding 327 amino acids.The degree of similarity of the nucleotide sequences in the CDS region of goat CREB compared with cow,human and mouse was 98%,95%and 95%,respectively.The degree of similarity of amino acid sequences was above95% for all species and the C-terminal b ZIP region is highly conservative.2.Difference lactation stages abundance showed that the expression of CREB gene in the peak lactation stage was significantly higher than that in the dry period.3.Overexpression CREB gene significantly increased the m RNA levels of lipid metabolic related genes SREBF1,FASN,ACACA,ELOVL6,LPL,FABP3,ACOX1,CPT1 B,ATGL and DGAT1 in cells and significantly up-regulated the desaturation index of Total C16:1 and cis-9 C18:1,as well as the intracellular triglyceride content.4.Interference CREB gene markly inhibited the expression levels of FASN,ACACA,SCD1,LPL,FABP3,CPT1 B,LPIN1 and GPAM.Meanwhile,interfering CREB gene significantly down-regulated the intracellular triglyceride content,but had no significant effect on the content and desaturation index of Total C16:1 and cis-9 C18:1.In summary,the CDS region of CREB gene was successfully cloned.Abundance alteration of CREB gene affectted the expression of genes related to fatty acid metabolism,the contents of monounsaturated fatty acids and triglycerides in GMEC.The results of this study laid experimental basis for the function research of CREB gene in lipid metabolism.