A Proteomic Analysis Of Ovine Follicular Fluid Proteins

The protein expression patterns of ovine plasma and follicular fluid at different development stages were constructed by using two-dimensional gel electrophoresis (2-DE). Differentially expressed proteins were detected by PDQuest 8.0software and subjected to ion trap mass spectrometer equipped with a Surveyor HPLC system, and differential spots of protein were identified.Follicular fluid is a product of both the transfer of blood plasma constituents that cross the blood follicular barrier and the metabolism of the granulosa cells.To find out the proteins expressed specifically in follicular fluid and the proteins related to oocyte develepment, the profiles of ovine plasma and follicular fluid proteome were compared.And 10 differentially expressed protein spots were found,and then subjected to ion trap mass spectrometer equipped with a Surveyor HPLC system.Only two kinds of proteins were identified: Ig heavy chain C region whose expression was down-regulated in follicular fluid and alpha-1-antitrypsin precursor whose expression was up-regulated in follicular fluid. Alpha-1-antitrypsin is thought to suppress oocyte development.Follicular fluid serving as the culture medium for the growth and differentiation of oocyte, during follicular maturation, constitutes the microenvironment for the oocyte. Certain components of follicular fluid might be of use as indicators for the maturation and thus the quality of the oocytes.To screen the biomarkers of oocyte maturation, the proteomic profiles of follicular fluid at different development stages were compared. And 10 differentially expressed protein spots were found,and then subjected to ion trap mass spectrometer equipped with a Surveyor HPLC system.Only three kinds of proteins were identified: beta-lactoglobulin precursor, transthyretin precursor whose expressions were both up-regulated during follicular maturation,and Ig lambda chain C region whose expression was down-regulated during follicular maturation. Beta- lactoglobulin and transthyretin are associated with the transportation of Vitamin A that plays important roles during oocyte maturation.This research laid a solid foundation for the further study of molecular biological and molecular genetic characteristics during follicular development, through screening the proteins related to follicular development and exploring the molecular mechanism of follicular development preliminarily.