A high-molecular-weight preovulatory stage-related protein in equine follicular fluid and granulosa cells

• Published in: Biology of reproduction Vol. 58; no. 2; pp. 551 - 557
• Main Authors: Gerard, N, Duchamp, G, Goudet, G, Bezard, J, Magistrini, M, Palmer, E
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.02.1998; Society for the Study of Reproduction - Oxford Academic
• Subjects: ANIMAL PROTEINS; Animals; Biological and medical sciences; Blotting, Western; BODY FLUIDS; CABALLOS; CELLULE DE LA GRANULOSA; CELULAS DE LA GRANULOSA; CHEVAL; CUMULUS OOPHORUS; Electrophoresis, Polyacrylamide Gel; Embryo, Mammalian - physiology; Female; Follicular Fluid - cytology; Follicular Fluid - metabolism; Follicular Phase - metabolism; Fundamental and applied biological sciences. Psychology; GRAAFIAN FOLLICLES; GRANULOSA CELLS; Granulosa Cells - chemistry; Granulosa Cells - metabolism; HORSES; Horses - physiology; JUMENT; Life Sciences; LIQUIDE BIOLOGIQUE; LIQUIDOS CORPORALES; Mammalian female genital system; MARES; Molecular Weight; Morphology. Physiology; OOCYTES; Other; OVA; OVAIRE; OVARIES; OVARIOS; OVULACION; OVULATION; OVULE; OVULO; Pregnancy; PREOVULATORY FOLLICLES; PREOVULATORY PERIOD; Protein Biosynthesis; PROTEINAS; PROTEINE; PROTEINS; Proteins - chemistry; Radioimmunoassay; Steroids - metabolism; Vertebrates: reproduction; YEGUA; Ovarian follicular fluid; Biochemical analysis; Preovulation; Protein; Follicular phase; Ovary; Vertebrata; Mammalia; Female genital system; Horse; Perissodactyla; Granulosa; Ovarian follicle; Ungulata
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod58.2.551

The high-molecular-weight proteins of equine follicular fluid were examined to determine whether some polypeptides are unique to certain physiological conditions. Fluids from ovarian follicles of various diameters and physiological stages during the follicular phase were recovered by ultrasound-guided follicular aspiration. Granulosa cells and cumulus-oocyte complexes (COC) were recovered by scraping the intrafollicular wall during puncture. Follicular fluids and corresponding serum, as well as granulosa cell lysates, were analyzed by one-dimensional SDS-PAGE and silver staining. COC morphology was assessed microscopically. A 200-kDa protein band was demonstrated in fluids from preovulatory follicles, in natural conditions or after induction of ovulation. This protein band was absent in fluids from follicles at earlier stages, subordinate follicles, and serum. The presence of this protein at the preovulatory (PO) stage was ascertained through recovery of the fluid from follicles twice during their growth. Its appearance was time dependent after induction of ovulation but was not induced by an intrafollicular injection of a physiological dose of progesterone. We also demonstrated the presence of this 200-kDa protein in granulosa cells lysates recovered from preovulatory follicles. The expression of this protein in the follicular fluid was related to the cumulus aspect and chromatin configuration of the enclosed COC. No relation was found between its presence in the follicular fluid at the PO stage and subsequent ovulation of the punctured follicle or embryo production. The identification of this molecule is approached and discussed. These results show a novel PO stage-related protein in equine follicular fluid, which may be involved in the differentiation and maturation mechanisms occurring in the follicle during the preovulatory period.