Fig. 1

Characterization of the phenotypes of cells within plexiform lesions. Representative serial hematoxylin and eosin (H&E)-stained sections and immunohistochemistry images showing histologic features and immunostaining results of plexiform lesions at different maturing stages from 4-week-old broiler chickens. The cells in the early immature lesion (left) exhibit endothelial-like morphology and those in more mature lesion (right) consist predominantly of foam-like macrophage cells. Immunohistochemistry analysis were performed using primary antibodies against monocyte/macrophage marker mannose receptor C-type 1 (MRC1), stem/progenitor cell marker CD133 and vascular endothelial growth factor receptor (VEGFR)-2. All immunostained sections are counterstained with hematoxylin. The dotted lines represent the edge of lesions