Figure 7. Pre‐implantation P₄ administration recovers epithelial necroptosis and trophoblast phagocytosis at the implantation site in Rb1^d/d mice.

1. In Rb1^d/d mice with pre‐implantation P₄ treatment, the fragmented uterine epithelial cells with the cytoplasmic lipid droplets were engulfed by the trophoblast cells. Scale bar = 2 µm. Arrowhead, cytoplasmic fragments engulfed by trophoblast; dotted line circle, lipid droplets in the cytoplasm; tr, trophoblast; le, luminal epithelium; s, stroma; red dotted line, stroma; green dotted line, luminal epithelium; blue dotted line, trophoblast.
2. Pre‐implantation P₄ treatment rescued the expression of MFG‐E8 on day 5 of pregnancy in Rb1^d/d uteri. Scale bar = 100 μm. Blue signal, nuclei stained by DAPI; yellow signal, MFG‐E8; le, luminal epithelium; s, stroma; arrowhead, embryo.
3. Pre‐implantation P₄ treatment recovered the expression of pRIP3, a mediator of necroptosis, on day 5 of pregnancy in Rb1^d/d uteri. Scale bar = 100 μm; blue signal, nuclei stained by DAPI; purple signal, pRIP3; le, luminal epithelium; s, stroma; arrowhead, embryo.