Pérez Fernando A, Roma Stella M, Cabada Marcelo O, Marini Patricia E
Cátedra de Histología y Embriología, Facultad de Ciencias Médicas (UNR), Rosario, Argentina.
Anat Embryol (Berl). 2006 Nov;211(6):619-24. doi: 10.1007/s00429-006-0114-0. Epub 2006 Sep 1.
In several mammals a sperm reservoir is formed at the isthmus of the Fallopian tube, providing viable, potentially fertile sperm for an extensive period. In pig (Sus scrofa) the spermadhesin AQN-1 seems to be involved in the establishment of the sperm reservoir. The pig oviductal protein, sperm binding glycoprotein (SBG), binds to sperm and exposes carbohydrate groups that can be recognized by AQN-1. In this study we obtain anti-SBG polyclonal antibodies and use them to localize SBG in the oviduct. Immunohistochemical analysis shows that SBG is present at the apical surface of isthmic and ampullar epithelial cells. The presence of SBG is limited to the upper two-thirds of the crypts of the isthmus and to cells located near the oviductal lumen in the ampulla. The ratio of the amount of SBG detected by western blot is 1:3 (ampulla:isthmus). Sperm entering the Fallopian tube probably contact the epithelial cells at the lumen before they reach the cells at the bottom of the folds. In vitro sperm can bind to isthmus and, at less extent, to ampulla. Thus, the localization and the relative amount of SBG in the isthmus and ampulla of pig's oviduct are compatible with its possible function in sperm binding to oviductal epithelial cells.
在几种哺乳动物中，输卵管峡部会形成一个精子储存库，在很长一段时间内提供有活力、具有潜在受精能力的精子。在猪（野猪）中，精子黏附素AQN-1似乎参与了精子储存库的形成。猪输卵管蛋白，即精子结合糖蛋白（SBG），能与精子结合并暴露出可被AQN-1识别的碳水化合物基团。在本研究中，我们获得了抗SBG多克隆抗体，并利用它们在输卵管中定位SBG。免疫组织化学分析表明，SBG存在于峡部和壶腹部上皮细胞的顶端表面。SBG的存在仅限于峡部隐窝的上三分之二以及壶腹部靠近输卵管腔的细胞。通过蛋白质印迹法检测到的SBG量的比例为1:3（壶腹部:峡部）。进入输卵管的精子在到达褶皱底部的细胞之前，可能先与管腔中的上皮细胞接触。体外实验中，精子能够与峡部结合，与壶腹部的结合程度较低。因此，猪输卵管峡部和壶腹部中SBG的定位及相对含量与其在精子与输卵管上皮细胞结合中可能发挥的功能是相符的。
