Expression Of The Ghrelin In Mongolian Sheep Granulosa Cells And Luteinizing Granulosa Cells

Ghrelin was identified in 1999 as the natural ligand of the GH secretagogue receptor (GHS-R), is considered to be a brain-gut peptide.At present, ghrelin protein in sheep expressed in the granulosa cells have been fully affirmed, but expression of ghrelin mRNA in granulosa cells have not been reported. Considering the important role of granulosa cells is highly related with the follicle development, espically related with the development of the oocytes. Also, granulosa cells will be transformed luteal cells after ovulation, so RT-PCR method, real-time RT-PCR technology, in vitro maturation and in vitro cell culturation was used in this study to explore expression levels of Mongolian sheep granulosa cells, the results as followed:1. RT-PCR assays using ghrelin specific primers produced a 233bp amplicon, consistent with the known size of ghrelin mRNA. DNA sequencing confirmed that the band was a 233bp ghrelin amplification product, and this cDNA contains 231 bp open reading frame (ORF), encoding the first 77 amino acid peptide ghrelin original sheep. The present study provided, for the first time, the presence of ghrelin mRNA in Mongolian sheep granulosa cells.2. Real-time RT-PCR results showed that relative ghrelin mRNA expression levels have no significant difference in cumulus cells and granulosa cells of the antral follicles (3-5 mm).3. Cumulus cells ghrelin mRNA expression of the relative in the different training time and maturity in the process of LH, FSH and E2 single hormone stimulation are gradually decreased.4. Based on the above the results, we expolre the possibility of luteinizing granulosa cells progress, realtive ghrelin mRNA expression level was considered a standard in this study, the resluts showed that granulosa cells stablly expressed of ghrelin mRNA expression until the 6th day. However, there was significantly decreased on the 9th day. Notably, ghrelin mRNA significantly decreased on the 12th day, on the 12th day of ghrelin mRNA expression levels uniform with the expression ghrelin mRNA of luteal cells from estrus corpora luteal.