Abstract:AIM: To investigate the relationships of the temporal and spatial expression profiles of Pax2, Sox2 and Prox1 during eye development in the embryonic mouse, and to gain further insight into their possible functions. METHODS: Time-mated embryonic C57/6 mice were killed at different developmental stages. The eye tissues were embedded in OCT and sectioned at 10μm. The sections were then mutually colabeled with Pax2, Sox2 or Prox1 and observed by fluorescence microscope. RESULTS: On E9.5, Sox2 transcripts were initially distributed throughout optic vesicle and lens placode. However, Pax2 was only expressed in the entire optic vesicle and Prox1 in the lens placode. At E11.5, Sox2 was still distributed throughout presumptive retina and lens vesicle. But Pax2 was more restricted to the proximal portions of the optic cup and stalk, while Prox1 was in the posterior portion of the lens vesicle. After E12.5, Sox2 was still distributed throughout retina and lens vesicle, but the positive expression intensity in lens vesicle was much lower in the retina. Meanwhile, Pax2 was only restricted in the optic stalk and Prox1 was gradually limited in the presumptive lens epithelium and the primary lens fibers. CONCLUSION: Expression patterns of Pax2,Sox2 and Prox1 were different, and they were overlapped during eye development in the embryonic mouse. The different expression patterns in eye which suggest that they play different roles in the developing eye may help to shape each respective structure.