IN-VITRO INCUBATION OF GOLDEN (SYRIAN) HAMSTER OVARIAN OOCYTES AND HUMAN SPERM WITH A HUMAN OVIDUCT SPECIFIC GLYCOPROTEIN

The objective of this study was to determine if human oviduct specific glycoprotein (huOGP) would associate with hamster ovarian oocytes and human sperm during in vitro incubation. The huOGP used in these studi es was partially purified from human hydrosalpinx fluid. Hamster ovari an oocytes and human sperm samples were incubated in culture medium wi th and without huOGP. Association of huOGP was assessed by indirect im munofluorescence assay using a polyclonal antibody prepared against hu OGP. Intense fluorescence of the zona pellucida, and bright but uneven fluorescence of the perivitelline space, were observed in hamster ova rian oocytes following incubation in the presence of huOGP. A similar but more uniform pattern of fluorescence was observed when hamster ovi ductal oocytes (positive controls) were incubated in culture medium al one. Fluorescence was absent when oocytes were assayed with preimmune serum. The association of huOGP with the zona pellucida and perivitell ine space appeared to be specific since thyroglobulin, a large molecul ar weight glycoprotein, and human serum albumin, the major protein in oviduct fluid, did not associate with the hamster oocytes nor inhibit huOGP association when included in the culture medium. Fluorescence wa s absent when human sperm incubated with huOGP were assayed with antis erum to huOGP. However, human sperm fluoresced when incubated with a u terine glycoprotein, CUPED, which had previously been shown to bind to cat sperm during in vitro incubation. Sperm also fluoresced brightly when human sperm antibody was used as a positive control. Solubilizati on of sperm membrane proteins postincubation and analysis of these pro teins by 1-D SDS-PAGE followed by immunoblotting also failed to show a n association of huOGP with human sperm. Electron microscopy of sperm both pre- and postsolubilization confirmed that the sperm membranes we re removed by this process. In conclusion, the association of huOGP wi th hamster oocytes in vitro suggests that huOGP may associate with hum an oocytes in vivo, whereas that may not be true for human sperm in vi vo. The association of huOGP with oocytes may serve to facilitate the process of fertilization and early embryonic development within the ov iduct. (C) 1994 Wiley-Liss, Inc.