Fig. 7. K14-Eda-A1 transgenic mice had ectopic mammary placodes, as visualised by whole-mount in situ hybridisation with Lef1 probe. At E11 the early placodes were initiated in both the wild-type (A) and transgenic (B) embryos. Mammary placodes 3 and 4 were seen as clear dots (M3, M4). Placode 2 (M2) had still a comet shaped appearance at this developmental stage. Placodes 1 and 5 were hidden by the developing limbs. At E11.5, M2-M4 are seen as clear dots in wild-type embryos (C), whereas supernumerary placodes (arrows) between M3 and M4 are evident in transgenic animals (D). At E12, the extra placodes were still visible in the transgenics (arrow in F) in contrast to the normal five placodes of wild-type animals (E).