Figure 3.

Examples of stem cell-based embryo models

(A) Schematic of a human gastrulation-staged embryo, showing the correspondence between the embryo and a micropatterned 2D colony of hESCs that differentiates into extra-embryonic (CDX2-positive, green), endodermal (SOX17-positive, yellow), mesodermal (Brachyury [BRA]-positive, red), and ectodermal (SOX2-positive, blue) (Warmflash et al., 2014) fate layers.

(B) 3D rendering of elongated gastruloids at 120 h, expressing Bra (red), Sox2 (blue), and Gata6 (yellow), resembling the post-occipital portion of the E8.5 mouse embryo (Beccari et al., 2018).

(C) Schematic of blastoids formed with ESCs (blue) and TSCs (green) (Rivron et al., 2018).

(D) A 3D rendered of an ETS-embryo comprising an epiblast-like compartment (OCT4-positive, blue) and trophoblast/ExE-like compartment (Eomes-positive, green), resembling an egg cylinder-staged mouse embryo (Harrison et al., 2017).

(E) An example of posteriorized embryonic-like sac (P-ELS) modeling human epiblast and amnion development. TFAP2A (green), a putative amniotic ectoderm marker. T (red), a primitive streak marker (Zheng et al., 2019).