Mouse placental 57-kDa calcium-binding protein: II. Localization of mRNA in mouse and human placentae by in situ cDNA hybridization.

Using a cloned cDNA to the mouse placental calcium-binding protein (MCaBP) [Tuan and Kirwin, preceding paper], mRNA transcripts of the MCaBP have been localized in the mouse placenta by in situ cDNA-RNA hybridization. The procedure involved the use of a nonradioactive, biotinylated cDNA probe. Paraffin sections of the mouse chorioallantoic placenta were processed for in situ hybridization using a procedure modified from that of Lo [8]. The results demonstrated that MCaBP mRNA is localized specifically to the fetal trophoblast of the mouse placenta, and is expressed in a development-dependent manner. The MCaBP cDNA also hybridized strongly in situ to sections of human term placenta, giving rise to signals localized specifically to the syncytiotrophoblastic layer of the chorionic villi.