Fig. 2.

Immunofluorescence microscopy of isolated, smooth muscle actin (SMA)-stained vessels from Prox1-green fluorescent protein (GFP) mice. Representative images of isolated popliteal (A–C), internodal inguinal axillary (Ing-Ax; D–F), mesenteric (G–I), and thoracic duct (TD, J–L) vessels were stained with anti-GFP (green) and anti-smooth muscle actin (red) to determine the degree of lymphatic muscle cell (LMC) coverage. Images are maximal projections of 1-μm image stacks taken from the outside to the midpoint of the vessel using a ×10 objective. Mean percent lymphatic muscle cell coverage and corresponding SE were quantified from tubular (nonvalve) sections of popliteal (n = 5), Ing-Ax (n = 5), mesenteric (n = 4), and TD (n = 5) vessels only; valve areas were included in the representative images to emphasize that valve areas are also populated with lymphatic muscle cells.