Fig. 4.

Stat3 ablation aggravated Shp2 retinal defects. (A) Stat3 depletion in the Six3-Cre; Stat3^flox/flox mutant retina did not affect ERK and AKT phosphorylation. In the Six3-Cre; Shp2^flox/flox; Stat3^flox/flox compound mutants, both Stat3 and ERK phosphorylation were disrupted. (B to E) Elimination of Stat3 did not cause an obvious retinal phenotype in the P21 Six3-Cre; Stat3^flox/flox mutant, but it accelerated retinal degeneration in the Six3-Cre; Shp2^flox/flox; Stat3^flox/flox compound mutants compared to the Six3-Cre; Shp2^flox/flox mutants. The sections were stained with hematoxylin and eosin (H&E). (F to I) Phospho-Stat3 was induced in the Six3-Cre; Shp2^flox/flox mutant and abolished in the Six3-Cre; Shp2^flox/flox; Stat3^flox/flox mutant. The arrowheads in panel G indicate phospho-Stat3-positive cells. Bar, 40 μm.