Kapur R P, Johnson L V
J Exp Zool. 1986 May;238(2):249-60. doi: 10.1002/jez.1402380215.
Previously, we identified a 215 kd glycoprotein, GP215, which is associated with postovulatory oocytes and embryos, but not with preovulatory oocytes (Kapur and Johnson, '85). In this paper a polyclonal antibody that specifically recognizes GP215 has been used to study the distribution of the molecule in association with ova and preimplantation embryos and in the female reproductive tract. GP215 is present in epithelial cells lining the cranial portions of the oviduct and in oviductal fluid, ovarian bursal fluid, and medium conditioned by oviductal tissue in vitro. Immunofluorescence assays of the ovum and early embryo show that GP215 is sequestered in the perivitelline space. Since preovulatory oocytes exposed to bursal fluid in vitro acquire GP215, we hypothesize that GP215 is synthesized and secreted by the oviductal epithelium and secondarily associates with the ovulated oocyte. Sequestration of GP215 within the perivitelline space is relatively specific since mouse serum albumin, a major constituent of oviductal fluid, and other high molecular weight proteins are not similarly retained. These observations indicate that the composition of the perivitelline space may be significantly different from the greater environment external to the zona pellucida such that fertilization and early development of mammalian ova potentially take place in a distinct perivitelline microenvironment.
此前，我们鉴定出一种215kd的糖蛋白，即GP215，它与排卵后的卵母细胞和胚胎相关，但与排卵前的卵母细胞无关（卡普尔和约翰逊，1985年）。在本文中，一种特异性识别GP215的多克隆抗体被用于研究该分子在卵子、植入前胚胎以及雌性生殖道中的分布。GP215存在于输卵管头部内衬的上皮细胞中，以及输卵管液、卵巢囊液和体外输卵管组织条件培养基中。对卵子和早期胚胎的免疫荧光检测表明，GP215被隔离在卵周隙中。由于体外暴露于囊液中的排卵前卵母细胞会获得GP215，我们推测GP215是由输卵管上皮合成并分泌的，随后与排卵的卵母细胞结合。GP215在卵周隙中的隔离相对具有特异性，因为输卵管液的主要成分小鼠血清白蛋白和其他高分子量蛋白质不会以类似方式被保留。这些观察结果表明，卵周隙的组成可能与透明带外部的更大环境有显著差异，从而使得哺乳动物卵子的受精和早期发育可能在一个独特的卵周微环境中发生。
