Fig. 5. FGF-induced fibre cell elongation and multilayering accompanied phosphorylation of ERK and could be blocked by UO126. Representative micrographs of cells in lens explants not exposed to FGF2 (A,B) or exposed to 100 ng/ml FGF2 (C-F) in the presence of DMSO (A-D) or DMSO with UO126 (E,F), immunolabelled for phospho-ERK (B,D,F) or counterstained with Hoechst dye (A,C,E). After 5 days culture with FGF, cells have elongated and multilayered as shown by the overlapping large ovoid nuclei (C). These cells also displayed a marked increase in phospho-ERK labelling (D) compared with epithelial cells of control explants (B). This FGF-induced activation of ERK was blocked in the presence of UO126 (F), which not only resulted in inhibition of cell elongation (compare D with F) but also multilayering of the cells (compare C with E). Scale bar: 50 µm.