Figure 2

Mammary gland transplantation. Fragments of epithelium containing mammary glands of eight to ten weeks old virgin mice (wt or RARα1/KO) were transplanted into number 4 glands pre-cleared of epithelium of three weeks old wild type or RARα1/KO animals (see Materials and methods). At week 11 (eight weeks after transplantation) the transplant-recipient glands and intact glands number 3 from the same mouse, as control, were processed for whole mounts. >90% of wt-FVB transplants repopulated the recipient gland while <50% of the FVB-RARα1/KO did (see Table 1).