Proliferation and apoptosis assays.

<p>A to H. Proliferation assays. Mice were injected with BrdU at P3, and retinas were dissected after an hour. BrdU incorporation in astrocyte progenitors was detected by anti-BrdU and anti-Pax2 double IF staining. A to F show representative images from areas indicated in G and H. Both Pax2⁺ and BrdU⁺ cells were counted with the assistance of NIH ImageJ program. I. Proliferation index was calculated as % of Pax2⁺ cells that were also BrdU⁺. Cre refers to GFAP^Cre. <i>n</i> = 4. No significant difference was found between <i>Hif-2α^f/f</i> and <i>Hif-2α^f/f/GFAP^Cre</i> mice. J to L. Apoptosis assay by anti-active Caspase 3 IF staining. J and K are P3 retinas. No apoptotic cells were detected in either <i>Hif-2α^f/f</i> or <i>Hif-2α^f/f/GFAP^Cre</i> mice. L is from mice treated with 75% oxygen for 16 hours between P7 and P8. The same anti-active Caspase 3 staining procedure detected large numbers of apoptotic cells in oxygen-treated mice. Images are representative of data from 4 mice in each group. Scale bars are 50 µm for A to F, 500 µm for G and H, and 50 µm for J to L.