Figure 3.

Mutation of −954 E-box in the wild-type −1696 α1T promoter prevents transgene induction in proliferating Müller glia after retina injury. a, Schematic representation of α1T promoter:GFP constructs. The wild-type −1696α1T:GFP transgene (-1696) and the 2 bp mutation created in the E-box at position −954 in the −1696 construct (TG-954CA) are indicated. b, Three independent lines of transgenic fish received retinal injuries on day 0 and were given a 4 h pulse of BrdU at 4 dpi. Note that none of the lines harboring the 2 bp mutation induced transgene GFP expression in BrdU-labeled Müller glia (arrowheads). See Figure 1 for comparison with the wild-type −1696α1T:GFP transgene response. The arrows in the lowest right GFP panel show transgene induction in retinal ganglion cells, the axons of which were presumably damaged when we injured the retina in this fish.