Fig. 1

Sfrp1 and Sfrp5 deficiency leads to excessive TGC differentiation and compromised placental development. a Average litter sizes of WT as well as Sfrp1 and Sfrp5 double knockout (dKO) mice. *P < 0.05. b Average number of implantation sites and implantation status of WT and dKO mice at E4.5. c Average weight of implantation sites and implantation status of WT and dKO mice at E7.5. d Average embryo degeneration rate and representative uteri of WT and dKO mice at E11.5. Arrows indicated degenerated embryos. *P < 0.05. e Hematoxylin and eosin (HE) staining of E8.5–E9.5 placental sections of WT and dKO mice. f Immunostaining analysis of cytokeratin (CK) on E9.5 placental sections of WT and dKO mice. g In situ hybridization analysis of the expression of Tpbpα and Pl1 in the placentas of WT and dKO mice, at E8.5 and E9.5. In a–d, numbers within the bars indicated the number of pregnant mice examined. Images in e–g are representatives of at least three independent experiments. Al, allantois; Ch, chorion; Cp, chorionic plate; Sp, spongiotrophoblast; TGC, trophoblast giant cell. Scale bar, 100 μm