Figure 5

Epcam⁺ trophoblast isolated from TS cell cultures and re-plated in TS media containing growth factors to promote proliferation formed small colonies after 2 days of culture but did not proliferate (A, compare Day 2 to Day 6). After 6 days in culture in TS media plus growth factors, the cells had not expanded and had the morphology of differentiated trophoblast, with large nuclei and cell bodies (compare Day 6 to Fig. 3, Day 2). Sca-1⁺ cells compared to Epcam⁺ cells displayed increased expression of the TS cell marker, Esrrb while Epcam⁺ cells expressed the syncytiotrophoblast marker, Gcm1 but not Sca-1 or Esrrb (B). Insets in (A) show morphology of plated Epcam⁺ trophoblast cells at high magnification (400x). Cells were stained with hematoxylin and eosin. Scale bar = 500 um.