Fig. 2. Kinetics of expression of pluripotency genes during differentiation of cESC. Proliferating cESC were induced to differentiate (A) by retinoic acid treatment at 10^-7 M for 5 days after plating or (D,E) by embryoid body formation for 4 days. Five independent experiments provided similar results. (B,C) As in A except that cycloheximide (B) or actinomycin D (C) was added to the culture medium at 10 µg/ml at T=0; two independent experiments provided similar results. Expression of some of the genes analysed, as measured by real-time RT-PCR, was downregulated (D) or upregulated (E). A value of 1 was assigned to expression levels at T=0, i.e. at the start of the induction of differentiation.