Figure 3.

Gene expression in cells grown in irradiated mouse embryonic fibroblast conditioned medium (CM) or unconditioned medium (UCM). Human embryonic stem cells were grown on Matrigel supplemented with noggin (incorporated at the time of Matrigel polymerization on the culture plates) and cultured in UCM or CM for 7 days and subsequently exposed to BMP4 (90 ng/ml) or media alone for 6 additional days. (a) Reverse transcription–polymerase chain reaction (RT‐PCR) analysis of trophoblast‐specific markers, hTFAP2α, hCGβ and Hand1, revealed that their expression was decreased in cultures grown in CM and expression was induced following treatment with BMP4. Oct4 levels seem to be similar between control and BMP4‐treated cells. (b) RT‐PCR analysis for expression of stem cell markers (Nanog and Cripto) as well as germ layer‐specific markers (Flk1‐endodermal, Nodal and Brachury T‐mesodermal, Pax6‐neuronal/ectodermal marker). Total RNA was isolated at the end of the culture period.