Fig. 5. Wild-type and JNK1^–/– MTEC display similar growth, morphology and production of mucin in culture. (A) Growth curves of MTEC derived from wild type and JNK1^–/– were conducted for the indicated times, and cell numbers were assessed by evaluation of total DNA content. (B) Wild-type and JNK1^–/– cells established tight junctions, as shown by scanning electron microscopy. (C) Wild-type and JNK1^–/– MTEC maintained in ALI for 10 days in the presence of 30 nM retinoic acid produced mucin. Media from two independent cultures from each condition were analyzed by slot blot analysis, using an anti-mucin antibody. Different dots shown represent results from independent samples.