Anomalous profile of FOXE3 expression in the lens of the Iberian mole. In the mouse lens, Foxe3 expression becomes polarised as soon as the primary lens fibres begin to differentiate (E12), remaining only in the epithelial cells but not in the differentiating lens fibres. This pattern is maintained in later stages (E16, E18) until adulthood. During mole lens development, FOXE3 is weakly detected in the lens pit (s4a stage). At the equivalent stage of mouse E12 (s5a), most of the cells, but not all, show a high expression of FOXE3, including the elongating primary lens fibres. In subsequent stages (s5b-s6), FOXE3 is observed mainly in the nuclei of cells located in the germinative zone, but also in single cells in both sides of the lens. At the s9 stage (newborn moles), FOXE3 is only expressed in a few epithelial cells (arrows). No FOXE3 was detected during the rest of developmental stages (not shown). Scale bar represents 200 μm in E16 and E18 figures, and 100 μm in all the rest.