The Study Of GnRH Analogues Regulating The Secretion Of Bovine FSH By MiR-488

Mammalian reproduction is mainly driven and guided by the hypothalamus pituitary gonad(HPG)axis,Gonadotropin releasing hormone(GnRH)is widely considered to be the hypothalamic peptide controlling reproduction.In view of the important regulatory effect of GnRH on the secretion of gonadal hormones in adenohypophysis,there have been synthetic GnRH analogues used in animal reproductive regulation and clinical treatment of various reproductive diseases.GnRH analogues combined with prostaglandin(PG)are commonly used in cattle Oestrus Synchronization Technology in China.GnRH analogues can promote the release of FSH and LH and act on the ovary,induce follicular development and promote ovulation,complete Oestrus Synchronization Timing insemination,and improve the conception rate.Gonarieline is a synthetic GnRH.The application of gonarieline in estrus synchronization can greatly reduce the cost of hormone use in production practice,and help to further study the specific regulatory mechanism of GnRH analogues on FSH.miRNA is a kind of endogenous non coding RNA.Research shows that miRNA plays a key role in the regulation of various physiological activities and cancer process,and it can participate in the secretion regulation process of various hormones.However,it is still unknown whether miRNA is involved in the regulation of GnRH on FSH secretion,and thus affects mammalian reproduction,which has important research value.In this study,30 cows were treated with GnRH analogues(gonarieline)and PG to make them oestrus at the same time.The changes of follicle development,FSH and LH secretion were detected before and after GnRH analogue treatment.It was found that GnRH analogue(gonarieline)was involved in the regulation of FSH secretion and induced ovarian follicle development.In order to further explore the molecular mechanism of this regulatory effect,bioinformatics softwares and Double Luciferase Report system were used to predict the miRNA that may be involved in the regulation of FSH secretion,and then the miRNA was verified on the primary rat adenohypophysis cells in vitro.After transfection of the mimics and inhibitors of miR-488,RT-qPCR,ELISA and other detection experiments were carried out to prove the targeting relationship between miR-488 and FSH,and the relationship between GnRH and miR-488 was verified.The results show that:1.The secretion level of FSH and LH in cows treated with GnRH analogues increased significantly,which promoted the development of ovarian follicles.The expression of FSHb and LHb mRNA was significantly increased in the pituitary after injection of gonarillin.Using the prediction software such as targetscan,combined with the Double Luciferase Report,we screened the miRNA differentially expressed after GnRH analog treatment,and predicted that miR-488 might target to regulate FSHb gene.2.The secretion of FSH and LH increased significantly,and the expression of FSHb mRNA was up-regulated,and the expression of miR-488-3p was down regulated.miR-488-3p may be involved in reproductive regulation.In vitro,miR-488-3p can target to regulate FSHb gene and affect FSH secretion.In conclusion,this study analyzed the changes of FSH and LH secretion after GnRH analogue treatment,determined the estrus synchronization procedure,analyzed the molecular mechanism of GnRH analogue regulating FSH secretion through miR-488,provided theoretical basis for improving the estrus control procedure of cattle,and promoted the domestic application of hormone products.