Increased angiogenesis in Matrigel plugs implanted in Lyl1-deficient mice. bFGF-containing Matrigel was subcutaneously implanted in both Lyl1-deficient and heterozygous mice (a total of 11 animals in each group in 2 experiments). Plugs were harvested at day 11, photographed (see supplemental Figure 4), and processed for histology. (A) Hematoxilin/Eosin staining of plug sections was visualized with a Nanozoomer slide scanner (Hamamatsu), and scanned images were analyzed with NDP.view software. Small insets show photograph of the corresponding Matrigel plug. Arrows indicate perfused small blood vessels in WT/Δ^Lyl1 plug section. Scale bars: 100 μm. (B) CD31 infiltration of Matrigel plugs: The entire surface of CD31-stained plug sections from Δ^Lyl1/Δ^Lyl1 and from their WT/Δ^Lyl1 littermates was visualized with a nanozoomer slide scanner controlled by the NDP.view software. (Left) Representative microscopy images of CD31 staining of plug sections from both genotypes. Scale bars: 100 μm. (Right) Entire plug sections were scanned and analyzed with ImageScope software (Aperio Technologies) using the “Positive Pixel count v9” algorithm. Shown is the quantification of CD31-staining expressed as a percentage of total plug surface. The data are presented as the mean ± SEM. Individual plugs from 2 independent experiments WT/Δ^Lyl1 (n = 7), Δ^Lyl1/Δ^Lyl1(n = 6), **P < .01.