Regulation Of MiR-486to Gene Pten Expression In Bovine Mammary Gland Development And Lactation

MicroRNAs(miRNAs) are conservative genes during evolution, and specific in expression among tissues and stages. Unique developmental feature during distinct stages of lactation makes the mammary gland a main goal which discover the way to control the cycles of cell, survival, proliferation, differentiation and death of cells.Recently, more and more studies have showed that miRNAs play a key role in the development of normal mammary gland and lactation, and there will be more studies about mammary gland. The microarray detected that the expression of miR-486in different development stages mammary tissues are obviously different. Pten has been found as tumor-inhibiting factor and widely study. But, we just obtain the tip of the iceberg knowledge have focused of the function of miRNA in normal mammary development,especially in bovine mammary gland.In this study, the function between Pten and miR-486was considered as a key point, and the result shows that Pten is modulated by miR-486in bovine mammary gland. Therefor, we know that miR-486is important in bovine mammary gland and lactation.The experiment results showed that:In the microarray analysis of this study, we found that bta-miR-486was higher in high quality lactation gland tissue than low quality tissue and pregnancy tissue, and expression of bta-miR-486was almost same between in low quality lactation stage and in pregnancy stage.And in situ hybridization proved that bta-miR-486was found primarily in mammary gland tissue rather than fat tissue.Ptew3’UTR-luciferase reporter vector was constructed and the result of miR-486about activity was detected by the Dual-Luciferase Reporter Assay System. The luciferase activity of reporter construction treated with miR-486was decreasedIndeed, our study confirmed that AKT, mTOR, and β-casein genes changes on account of Pten, and whether the Pten level changed, it suggested that depended on bta-miR-486. Overexpression of bta-miR-486inhibited the expression of Pten both in mRNA level and protein level, and thus the process stimulated AKT, p-AKT, mTOR, p-mTOR and β-casein.Our study offered a pathway to enter nuclear for Pten, the group of overexpressive bta-miR-486demonstrated Pteft-reducing in bovine mammary epithelial cell nucleus, however, the group of lacking miR-486boosted the Pten in nucleus.Because of the acceleration of bta-miR-486, we found it could speed mammary epithelium cells proliferation and differentiation, the synthesis and lactation of milk, lipid and lactose. These conclusions have been well proved that the bovine epithelium tissue and cells are affected directly by increasing of bta-miR-486.