Fig. 3. Angiopoietin pathway responses downstream of Akt regulate hyaloid regression. (A,B) X-Gal staining of P5 hyaloid vessels from Ang2^+/lacZ mice. Dashed red box in A indicates region shown at higher magnification in B. Red arrowheads indicate X-Gal-labeled cell processes, the red bracket indicates a small capillary with limited X-Gal staining. Macrophages are indicated by the dashed red circles. (C) Pericytes from P5 hyaloid vessels of wild-type mice labeled with desmin (red). Nuclei are stained with Hoechst 33258 (blue). White arrowheads indicate cell processes of the pericytes, the white bracket indicates areas with no desmin staining. (D) X-Gal staining of P5 hyaloid vessels from a Tie2-lacZ mouse in which lacZ is expressed in vascular endothelial cells (VECs). The red bracket indicates a small capillary with uniform X-Gal staining. (E-I) Hoechst 33258-labeled hyaloid vessels from control (E,H) and VE-cadherin:tTa; TET:myrAkt (F,G,I) transgenic animals. (J) Proportion of BrdU-positive cells in P5 hyaloid vessels of WT, Ang2^lacZ/lacZ, WT injected with Ang1 and VE-cadherin:tTa;TET:myrAkt mice. (K) Number of apoptotic events at P5 in the hyaloid vessels from mice of the indicated genotypes. (L) Hyaloid vessel number at P8 in mice of the indicated genotypes. (M,N) TUNEL labeling of hyaloid vessel preparations with no treatment (M) or after intravitreal injection of SH6 (N). (O) Quantification of healthy hyaloid vessel number as a proportion of wild type after injection of the indicated reagents at P4 and assessment at P5. Magnifications: 50x (E-G), 200x (A), 400x (M,N), 630x (B,C,D,H,I). Significance levels: ^**P0.01, >0.001; ^***P0.001, >0.