Figure 7. Notum regulates the formation of sharp boundaries between neighboring cell fates.

(A) In utero lentiviral delivery strategy to conditionally ablate Notum in R26dtTomato embryos. (B–C) Representative whole-mount immunofluorescence showing LEF1 intensity profile and population size in Notum ^-/+ and Notum^-/- skin. Red boxes denote regions magnified below each image. Note that Notum ablation (but not heterozygous) leads to an increase in LEF1 signal and LEF1+ cell populations in the WNT signaling progenitor cells (n ≥ 75 hair follicles from ≥3 different litters analyzed; Mann-Whitney test *p=0.0332 and ***p=0.0002; n.s. non-significant; red lines represent the distributions’ median).