Immunodetection of c-MAF in different stages of the Iberian mole lens development. At 12 dpc (E12), c-Maf is expressed in all the cells of the mouse lens. At later stages (E18), it is down-regulated in the epithelial cells, being expressed mainly in the differentiating lens fibres. In the mole, c-MAF is detected in the lens pit (s4a). From the beginning of primary lens fibre differentiation, fibre cells appeared more immunoreactive than epithelial cells, although both cell types were clearly c-MAF-positive (s5a-s6). However, some single cells showed no evident c-MAF expression in postnatal stages (s11) (arrows). Scale bar represents 200 μm in E18 figure, and 100 μm in all the rest.