Fig. 2. Accelerated ductal extension, excessive side-branching and precocious lobuloalveolar development in wild-type virgin and MTA1-TG females. (A) Whole-mount preparations of wild type (a) and MTA1-TG mammary gland (b) at 6 weeks of age. (Right panel) Quantitative representation of distances from the center of the lymph node to the far end of terminal end-buds (five to seven mice per line). (B) Carmine Red-stained whole mounts of inguinal mammary glands from control (a,b) and MTA1-TG mice (d,e) at 12 weeks of age. Images in b and e are higher magnifications of a and d. Hematoxylin and Eosin-stained sections of mammary glands of 12-week-old wild-type (c) and MTA1-TG mice (f-i). Dilated ducts (f), increased budding (h), a lobuloalveolar-like structure (g) and an indistinct epithelial-stromal boundary (arrowhead, i) can be seen in the mammary glands of MTA1-TG mice. Western blot showing expression of ß-casein (C) and ß-catenin (D) in mammary glands of 12-week-old wild-type and virgin MTA1-TG mice. Cytokeratin 18 used as a control for epithelial cell content. Vinculin was used as a loading control.