FIG.8.

Increased expression of Wnt-4 and Wnt-6 is observed in JNK1^−/− EB cultures and the Wnt antagonist, sFRP2, increases morphological neural differentiation. (A) The indicated ES cell lines were submitted to the 2−/2+ EB differentiation protocol and subsequently cultured on polyornithine-laminin-coated dishes for 5 to 7 days as described in Materials and Methods. Total RNA was purified, and the expression of Wnt-4 and Wnt-6 mRNAs were measured as described in Materials and Methods by quantitative RT-PCR using the primers listed in Table 1. The results are the average relative expression and standard errors of the means normalized for GAPDH of three to five independent experiments reflecting three independent RNA preparations. (B) JNK1^−/−.1 ES cells were submitted to the 2−/2+ EB protocol and subsequently cultured on polyornithine-laminin-coated dishes in medium with or without 1 μg/ml sFRP2 (R&D Systems, Minneapolis, MN) for 6 days and photographed through a phase-contrast microscope.