Extended Data Fig. 4: Additional histological identification of placental cell types.
From: Cell type and cell signalling innovations underlying mammalian pregnancy
a-b. The opossum fetal-maternal interface, showing 3 layers of yolk sac endoderm (YSC), cytotrophoblast (CTB), and syncytial knots (TGC), in apposition with maternal luminal epithelium (LE) which produces secretory bodies (*); maternal glandular epithelium (GE) lies closely underneath the lumen. c-d. The tenrec invasion front, where trophoblast invades into mucus-filled glands, eroding the glandular epithelium (GE) immunoreactive for pan-cytokeratin stain (CK AE1/AE3). e-f. KRT7+ trophoblast in the guinea pig surrounding decidual stroma (left) and maternal arteries (MA; right). g-h. Invasive syncytiotrophoblast (SCT) in the guinea pig emanates from subplacental cytotrophoblast (left) and extends into stroma where necrotic patches develop (right). i. Trophoblast giant cell observed in the subplacenta of the guinea pig (proximate to subplacental CTB), but these cells were not captured by droplet-based sequencing. Scale bars: 200 μm. Silhouettes from PhyloPic under a Creative Commons licence: tenrec, Yan Wong (CC0 1.0); macaque, Jane Whitehouse (CC0 1.0); mouse, Michael Keesey (PDM 1.0).
