Spatiotemporal expression pattern of PROX1 in the Iberian mole lens. In mouse samples (E12, E18), specific Prox1-immunofluorescence is observed in the nucleus of differentiating lens fibres and in the cytoplasm of epithelial cells. During the mole lens development, PROX1 showed a cytoplasmic distribution in the invaginating lens placode (s4a). Once the lens vesicle becomes polarised, PROX1 is highly detected in the nucleus of all the lens cells (s5a, s5c). From the s6 stage on, cytoplasmic localisation of PROX1 is clearly seen mainly in posterior fibre cells but also in the lens epithelium. Photomicrographs were taken using a single bandpass fluorescence mirror unit and merged with 'The Gimp' software. Scale bar represents 100 μm in all figures. LE, lens epithelium; FC, fibre cells; LP, lens pit.