Figure 1.

Characterization of Ws/Ws and wild type adult rat mammary glands. Panel A: Mammary whole mounts of normal wild type and Ws/Ws rats. Both glands show a dense ductal network with multiple branching points. Panel B: Histological sections of the glands depicted in Panel A. As expected, the only morphological difference is the absence of mast cell in the Ws/Ws animals. LN: lymph nodes. Ws/Ws: c-kit null rats. Immunohistochemistry: positive cells stained brown; Harris's hematoxylin was used as counterstaining. Scale bars: Panel A: 3.2 cm; Panel B: 50 μm.