Yamada O, Todoroki J, Kizaki K, Takahashi T, Imai K, Patel O V, Schuler L A, Hashizume K
Laboratory of Reproductive Biology and Technology, National Institute of Agrobiological Sciences, Ikenodai 2, Kukizaki, Inashiki Ibaraki 305-8602, Japan.
Reproduction. 2002 Sep;124(3):427-37.
The bovine placenta secretes multiple molecules during implantation and placentation, many of which are produced by binucleate cells. In this study, production of prolactin-related protein I (PRP-I), a member of the non-classical prolactin-related family, was investigated during the implantation period in cows. Expression of bovine PRP-I (bPRP-I) in the placentome was examined during the preimplantation (days 17-19), implantation (days 20-25) and post-implantation (days 30-60) periods by immunohistochemistry, immunofluorescence and in situ hybridization. During the preimplantation period, both bPRP-I and bovine placental lactogen (bPL) were undetectable in trophoblastic cells. Both bPRP-I mRNA and protein appeared first at day 20 of gestation in trophoblastic binucleate cells and multinuclear cells that might migrate into the endometrium and fuse to epithelium; however, no bPL was detected in binucleate cells at this time. After implantation, on day 30, both bPRP-I and bPL were detected in binucleate cells and were co-expressed in the same cells. These data indicate that bPRP-I may play a role before implantation and that bPRP-I may be an excellent marker for trophoblastic cell differentiation, as well as a candidate for pregnancy diagnosis.
牛胎盘在植入和胎盘形成过程中分泌多种分子，其中许多是由双核细胞产生的。在本研究中，对非经典催乳素相关家族成员催乳素相关蛋白I（PRP-I）在奶牛植入期的产生情况进行了研究。通过免疫组织化学、免疫荧光和原位杂交技术，检测了植入前（第17 - 19天）、植入期（第20 - 25天）和植入后（第30 - 60天）胎盘小叶中牛PRP-I（bPRP-I）的表达。在植入前期，滋养层细胞中未检测到bPRP-I和牛胎盘催乳素（bPL）。bPRP-I mRNA和蛋白最早在妊娠第20天出现在可能迁移到子宫内膜并与上皮融合的滋养层双核细胞和多核细胞中；然而，此时在双核细胞中未检测到bPL。植入后，在第30天，bPRP-I和bPL均在双核细胞中被检测到，并在同一细胞中共表达。这些数据表明，bPRP-I可能在植入前发挥作用，并且bPRP-I可能是滋养层细胞分化的良好标志物，也是妊娠诊断的候选标志物。
