Fig. 2.
Loss of NRP2 impedes branching morphogenesis and invasion of epithelial cells into the mammary fat pad. (A) Schematic of method for quantification of mouse mammary gland development. Each whole-mounted mammary gland was divided into six areas by positioning their central lymph nodes at position 1.5 from the left (central line of the body). The number of mammary ducts crossing each line, ductal outgrowth and body weight were determined for quantification of relative mammary gland development. MMTV-Cre;NRP2loxP/loxP mice were compared with MMTV-Cre;NRP2+/loxP or MMTV-Cre mice for branching density and mammary gland outgrowth, as well as body weight. For each experimental group, 6-18 mice were analyzed at each of four developmental stages (5, 7, 9 and 12 weeks old). LN, central lymph node; TEB, terminal end bud. (B) Effect of NRP2 loss on branching density. (C) Effect of NRP2 loss on mammary gland outgrowth. (D) Body weights were compared as an index for overall development. All experimental groups exhibited similar rates of body weight increase with age. For all graphs, error bars represent s.e.m., *P<0.05.