Genetic inhibition of JNKs in differentiating ES cells. (A) Flag-tagged dominant-negative mutants of JNK1 and JNK2 (JNK1a1-apf and JNK2a2-apf) were conjugated with IRES-DsRed for the tracing of the consistently expressing cells. (B) The expression of flag, phosphorylated JNKs, phosphorylated c-Jun (pc-Jun) and total amount of JNK1 and JNK2 were revealed by western blot. (C) Their efficiencies of neural formation were estimated by FACS analyses. The expressions of neural markers are also examined, such as Sox1 (D), nestin (D) and N-cadherin (N-cad) (E).