Fig. 4. Sequential expression of endothelial (A) and mesodermal genes (B). RT-PCR analysis was carried out on total RNA isolated at different stages of TC13 cell differentiation. Each amplification was carried out using the appropriate amount of cDNA as determined from a dose-response curve. For PCR conditions, please refer to Table 1. Amplified products were resolved on 1.2% agarose gels and visualized under UV light. (C) Gel shift analysis of NF-AT proteins in extracts from TC13 cells treated with RA for 0 (–) or 24 (+) hours. Specific complexes corresponding to NF-ATp and NF-ATc (Timmerman et al., 1997) are displaced by 100-fold excess of cold probe (competitor). Note how NF-ATc complexes are increased in RA-treated extracts. N.S, nonspecific.