Figure 4
From: Chorioallantoic placentation in Galea spixii (Rodentia, Caviomorpha, Caviidae)
The trophospongium in early pregnancy. (A,B) HE. Cellular trophoblast (ct) at the placental margin (fetal side, opposite the decidua) covers internally-directed lamellae of fetal mesenchyme (arrow), situated near to the maternal blood channels (mbc). The placental surface is defined by a villous parietal yolk sac (pys). (C) TEM. Cells in the trophospongium show mitotic figures, signifying proliferation activity. (D) Immunostaining for PCNA, indicated by red nuclei, likewise reveals high proliferation activity of the trophoblast cells. Scale bars = 0.1 mm for histology and 2 μm for TEM.