Biosynthesis and Immunocytochemical Localization of an Estrogen-Dependent Glycoprotein and Associated Morphological Alterations in the Sheep Ampulla Oviduct1

Abstract

Published reports have shown that an M(r) 90,000-92,000 protein is released into the oviductal lumen of the sheep, during estrus at a time corresponding to ovulation and fertilization, where it associates with the embryo. The objectives of this study were (a) to determine whether estradiol-17 beta (E) alone or in combination with progesterone (P) induces the synthesis of the M(r) 90,000-92,000 protein from the ampulla and/or isthmus oviduct; (b) to monitor structural alterations in oviductal epithelial cells associated with the synthesis of this protein; and (c) to generate a polyclonal antiserum to the protein and use the antiserum to verify its cellular location and tissue specificity. Oviductal flushings and explant culture media were obtained from ovariectomized animals treated with E alone or with E plus P. The M(r) 90,000-92,000 protein was present in 3H-leucine- and 3H-glucosamine-labeled culture media of the ampulla (not isthmus) oviduct in animals treated with E alone or with E plus P. The glycoprotein was detected in gels of oviductal flushings obtained from animals treated only with E. A specific polyclonal antiserum to the protein was made and cross-reacted on Western blots of oviductal flushings from E-treated animals and ampulla (not isthmus) oviduct culture media from animals treated with E alone or with E plus P. The secretory apparatus of the epithelial cells of the ampulla oviduct matured and differentiated in response to E. Light and electron microscopic immunocytochemistry localized the M(r) 90,000-92,000 glycoprotein to secretory granules in the nonciliated cells of the ampulla oviduct. Immunoperoxidase reaction product was absent in tissue sections and Western blots of other reproductive and nonreproductive tract tissues obtained from steroid-treated animals. Therefore, the secretory cells of the ampulla oviduct of the sheep synthesize and release an E-induced, oviduct-derived M(r) 90,000-92,000 glycoprotein.

Influence of maternal environment on the number of transferable embryos obtained in response to superovulatory FSH treatments in ewes

“…Firstly, as described above, the number of viable embryos was related to the oestradiol concentrations around oestrus, but oestradiol is not only the signal of a healthy population of preovulatory follicles. Oestradiol induces maturation and differentiation of the secretory apparatus of the epithelial cells of the sheep ampulla oviduct [30]. In response to the oestradiol levels around the oestrus [31], these cells synthesize and secrete a specific oestrus-associated glycoprotein (oEGP) which regulates embryo development [32].…”

Induction of Dog Sperm Capacitation by Glycosaminoglycans and Glycosaminoglycan Amounts of Oviductal and Uterine Fluids in Bitches.

“…Thus, the GAGs in the fluid secreted by the genital organs of bitches may serve to accelerate the capacitation of dog sperm. The secretory function of oviductal epithelial cells has been found to become active in the estrous period of different species [1,18,27], and non-ciliated cells in the ampulla of the oviduct have been observed to secrete large amounts of glycoproteins in estrous ewes [27] and mice [26]. Furthermore, it has been reported that the oviductal fluid of estrous cows contains a large volume of GAGs [2,8,17], and GAGs have been detected not only in the oviductal fluid of the cow [17] and ewe [18] but in their uterine fluid as well.…”

Morphological features of epithelial cells in the sheep isthmus oviduct during early pregnancy

“…The differences are difficult to explain, since even within the primate species variations in sensitivity to fluctuations estradiol and progesterone have been seen. The presence of ciliated cells in the isthmus, ampulla (Murray, 1992(Murray, , 1995 and fimbria Murray, 1996) oviducts of long-term ovariectomized ewes indicates that the sheep lacks a steroid-dependent ciliation-deciliation process which characterizes the oviducts of human (Verhage et al, 1979) and nonhuman primates (Rumery et al, 1978;Brenner and Slayden, 1994;Verhage et al, 1990), cats (Verhage and Brenner, 1975) and dogs (Verhage et al., 1973). In the sheep, this could account for the lack of significant changes as estradiol levels fall and progesterone levels rise at day 3 of pregnancy (Bazer and First, 1983).…”

“…Using biochemical and molecular analyses, we have shown that the isthmus oviduct of the sheep does not express or synthesize the Mr 90,000-116,000 protein (Murray, 1992(Murray, , 1993DeSouza and Murray, 1995). Immunocytochemistry and in situ hybridization have failed to detect the Mr 90,000-116,000 protein or its mRNA, respectively, in tissue sections of the estrogen-dominated isthmus epithelium (Murray, 1992;Murray and DeSouza, 1995). The data presented here provide additional cytological evidence for the lack of cellular stores of the estrogendependent oviduct glycoprotein in ciliated or nonciliated cells.…”

“…Isthmus oviducts (,2-3 mm) were immersion-fixed in a Hepes-buffered solution containing 1% (v/v) glutaraldehyde and 3% (w/v) paraformaldehyde for 2 h at room temperature and embedded in Araldite as previously described (Murray, 1992). For cytomorphometrics thick (1 µm) sections were cut on a Sorval MT-2B ultramicrotome, stained with toluidine blue and analyzed using a Zeiss brightfield microscope.…”