Expression of eGFP protein in the placentome at day 90.

<p>(A) On top the fetal side (FS) containing arcade zone (AZ) and villous areas (VA) with close intermingling of fetal and maternal tissues (MT). (B–C) Details of the arcade zone showing the trophoblast cells (T) and maternal uterine epithelium (M) positive for eGFP; endometrial stroma (EE) was mostly negative. Details of the arcade zone showed similar staining, including a binucleated trophoblast giant cell (arrows). Please note that some binucleate trophoblast giant cells are strong positive for eGFP while others are not. In (D–F), the presence of syncytial regions (arrows) in the villous region. Please note the fetal cells in close contact to the maternal epithelium displays weak staining to eGFP (arrows). (G) Negative control: placenta derived from a normal pregnancy that was stained for eGFP detection. trophoblast (T), endometrial stroma (EE), maternal uterine epithelium (M).