Fig. 8. Expression pattern of Jun during chondrogenesis in vivo and in vitro. (A) Type II collagen and Jun in wing buds of day 5 and 6 chicken embryos were detected by immunohistochemistry. (B) Mesenchymal cells from chicken embryo were maintained as a micromass culture for 4 days, and distribution of type II collagen and Jun was detected by immunocytochemical staining of cross-sections of a micromass culture spot. (C) Mesenchymal cells were maintained as micromass culture for the indicated period to induce chondrogenesis. (D) Alternatively, the cells were cultured for 4 days in the presence of vehicle alone as a control (Con), 10 nM phorbol ester (PMA), 1 µM Go6976 (Go) or 10 µM PD98059 (PD). Type II collagen, ß-catenin and Jun were detected by western blotting.