Fig. 4.

Tracking studies show that G8^pos cells responding to injury of the lens epithelium were progeny of G8^pos cells present at the time of wounding. G8^pos cells in lens epithelial ex vivo explants were tagged at T0 with G8 mAb and a rhodamine-conjugated secondary antibody. Explants with tagged G8 cells were incubated and the G8 cells tracked for 24 h (A–F) or 72 h (G–I) after the time of injury, at which time they were fixed and labeled again with the G8 mAb, this time tagged with an Alexa Fluor 488-conjugated secondary antibody. A–C and G–I are expanded niches, and D–F are cells at leading edge. All cells that labeled with the Alexa Fluor 488-tagged G8 (B, E, and H) also were labeled with the tracked rhodamine-tagged G8 (A, D, and G), as seen in the overlays (C, F, and I). These results demonstrated that the G8^pos cells that participated in healing of the lens epithelium were derived from the G8^pos precursor cells present at the time of injury and did not include cells later recruited to the G8 lineage. (Scale bars: 20 μm.)