Fig. 3
From: A pluripotent stem cell-based model for post-implantation human amniotic sac development
Asymmetric cyst resembles the post-implantation human amniotic sac. a 3D rendering of a representative asymmetric cyst on day 5, stained for EZRIN (green) and OCT4 (red), flanked by X-Z (bottom) and Y-Z (right) views. HOECHST (blue) counterstains nuclei. n = 4 independent experiments. Scale bar, 50 µm. b Representative confocal micrographs showing a day 5 asymmetric cyst stained for OCT4 (green), NANOG (red), and WGA (wheat germ agglutinin; purple). HOECHST (blue) counterstains nuclei. n = 6 independent experiments. Scale bar, 50 µm. c Representative confocal micrographs showing a day 5 asymmetric cyst stained for OCT4 (green), SOX2 (red), and WGA (purple). HOECHST (blue) counterstains nuclei. n = 3 independent experiments. Scale bars, 50 µm. d Representative confocal micrographs showing a day 5 asymmetric cyst, stained for TFAP2A (green), OCT4 (red), and WGA (purple). HOECHST (blue) counterstains nuclei. Zoom-in images are shown for the boxed regions at the amniotic pole. n = 3 independent experiments. Scale bar, 50 µm. e Representative confocal micrographs showing a day 5 asymmetric cyst stained for GATA3 (green) and WGA (red). HOECHST (blue) counterstains nuclei. Zoom-in images are shown for the boxed regions at the amniotic pole. n = 2 independent experiments. Scale bar, 50 µm. f qRT-PCR analysis of TFAP2A, GATA3, and SOX2 in week 16–17 human fetal amniotic epithelial cells. Data were normalized against GAPDH and plotted as the mean ± s.e.m. with n = 3 biological replicates. P-values were calculated using paired, two-sided Student’s t-test. **P < 0.01. g Schematic of the asymmetric cyst. The squamous side resembles the amniotic ectoderm lining the roof of the amniotic sac, while the columnar side recapitulates the embryonic disc lining the floor of the amniotic sac, with the amniotic cavity enclosed within. Together, the asymmetric cyst models the morphology and cell fate pattern of the amniotic sac in the post-implantation human embryo. The asymmetric cyst is thus termed the post-implantation amniotic sac embryoid (PASE)
