Fig. 2. Effect of AREG and EGFR deficiency on postnatal mammary development. (A) Carmine-stained whole mounts of paired wild-type, Areg^–/– (upper left and lower right panels) and recombined mammary transplants grown for 3 weeks in the presence of estradiol pellets. Scale bar: 1 mm. (B) Epithelial areas of 3-week-old, estradiol-stimulated transplants with the indicated epithelial and stromal genotypes (A^–/–, Areg^–/–; WT, wild type). Lines connect paired contralateral transplants from individual host mice and single data points represent unpaired transplants. (C) Whole mounts of wild-type, Egfr^–/– and recombined 3-week-old transplants. Scale bar: 1 mm. (D) Epithelial areas of 3-week-old transplants with the indicated epithelial and stromal genotypes (R^–/–, Egfr^–/–). (E) Histological appearance of paired transplants. Similar alveolar morphologies and accumulation of luminal secretory products (arrowheads) were seen in paired transplants from individual hosts, regardless of the transplant genotype. Scale bar: 50 µm.