Fig. 8. EphA2-deficiency impairs endothelial cell survival in vivo. (A) Matrigel plugs harboring MPMEC isolated from heterozygous (+/–) or EphA2-deficient (–/–) mice were collected 4 days (not shown) or 10 days post-transplantation and co-stained for LacZ expression and the proliferation marker Ki67. Arrows indicate LacZ+/Ki67+ nuclei, and the asterisks indicate LacZ+/Ki67–nuclei. Scale bar, 2.5 µm. (Right) The percentage of LacZ+/Ki67+ nuclei relative to total LacZ+ nuclei in each field was calculated to quantify proliferation in exogenous endothelial cells. (B) Matrigel plugs were also subjected to staining for LacZ followed by TUNEL assay to detect apoptosis at 10 days (left). Arrows indicate LacZ+/TUNEL+ nuclei, and the asterisks indicate LacZ+/TUNEL–nuclei. Scale bar, 5 µm. (Right) The percentage of LacZ+/TUNEL+ nuclei relative to total LacZ+ nuclei in each field was calculated to quantify apoptosis in exogenous endothelial cells. Data are means±s.d. of three independent samples/condition. Significant differences in percentage of apoptotic nuclei are indicated where P<0.01 using Student's t-test: ^*P=0.003 EphA2^+/– versus EphA2^-/– 4-day plugs, ^**P=0.03 EphA2^+/– versus EphA2^-/– 10-day plugs.