Symposium: reproduction in baboons. The baboon oviduct: characteristics of an oestradiol-dependent oviduct-specific glycoprotein

Abstract

The baboon oviductal epithelium differentiates into a tall columnar epithelium consisting of ciliated and secretory cells during the follicular phase of the menstrual cycle in response to rising oestradiol levels. The apical tips of these secretory cells are filled with membrane-bound secretory granules. During the luteal phase when progesterone levels are elevated, the epithelium regresses and deciliation occurs. Analysis of secretory proteins obtained from explant culture media by SDS-PAGE followed by fluorography or Western blots has revealed that the baboon oviduct synthesizes and secretes a high molecular weight glycoprotein during the follicular phase of the cycle. Immunocytochemistry demonstrated that this oviductal glycoprotein is localized to the secretory granules of epithelial secretory cells, is oviduct specific, and that following secretion the oviductal glycoprotein binds to the zona pellucida and perivitelline space of ovulated oocytes and embryos within the oviduct. Similar proteins have been characterized in other mammalian species. cDNA data show that the complete coding sequence is 2228 bp for a protein of 623 amino acids. A Genbank search showed that baboon oviductal glycoprotein has high homology to other oviductal glycoprotein sequences at both the nucleotide and amino acid levels. Studies conducted to date probing the biological function of oviductal glycoprotein indicate that this protein plays a role in prefertilization reproductive events (sperm capacitation; sperm-zona binding; zona penetration). Additional experiments are needed to reveal a specific function and mechanism for this molecule.

Is the Zona pellucida Thickness of Metaphase-II Oocytes in an IVF/ICSI Program Influenced by the Patient’s Age?

“…[17] and lead to morphological and biochemical changes in the Z.p. The secretion of various proteins lies predominantly under the control of estrogen [18]. This supports the notion that the formation of a thick or thin Z.p.…”

Identification of a Novel Acidic Mammalian Chitinase Distinct from Chitotriosidase

“…These include oviduct-specific glycoprotein from several mammalian species (reviewed in Refs. [25][26][27], human HC gp39/YKL-40 (28,29), mouse BRP39 (30), pig gp38K (31), human YKL-39 (32), and mouse YM1/ECFL/MCRP (33,34). The functions of these proteins, of which some have been shown to express lectin-like properties (35), are at present unknown.…”

Selection of highly fertilization-competent bovine spermatozoa through adhesion to the Fallopian tube epithelium in vitro

“…The oviductal microenvironment exerts several positive effects on bovine gametes and embryos: (1) adhesion to the oviduct prolongs the fertile life of spermatozoa (Pollard et al, 1991); (2) oviductal fluid (Grippo et al, 1995) and media conditioned by oviduct epithelial cells (Chian and Sirard, 1995) improve the ability of spermatozoa to penetrate the oocyte; (3) a bovine oviductal specific glycoprotein, which is conserved in several mammals, increases the fertilization rate by an oocyte-specific effect (Verhage et al, 1997;Martus et al, 1998); and (4) embryo development is promoted by co-culture with oviductal cells (Eyestone and First, 1989;Ellington et al, 1990;Mermillod et al, 1993). However, until now the lack of a method to recover the spermatozoa adhering to the oviductal epithelium limited the analysis of the role played by the oviduct in sperm selection.…”