Fig. 6. ß-Catenin pathway activation induces Edar but not Eda. (A) Embryos infected with a virus that activates the ß-catenin pathway show ectopic and precocious expression of Edar in the presumptive feather tract (PT) ahead of the morphogenetic wave, as well as in the pseudoapteria (PA). (B) Subsequent detection of viral transcripts in the same embryo reveals infection in the areas of ectopic expression. (C,D) Higher magnification of the boxed areas in A and B reveals a correspondence between infection (D) and ectopic Edar expression (C) in coherent patches of infection (arrows). (E) Embryos infected with this virus also show ectopic expression of Eda ahead of the morphogenetic wave. (F) Subsequent detection of viral transcripts shows infection in the areas of ectopic expression. (G,H) higher magnification views of the boxed areas in E and F show the induced expression of Eda (black arrows, G) is in dermis surrounding the dermal condensations induced indirectly by foci of infection with the ß-catenin virus in the epidermis (black arrows, H). Foci of infection within the bud (red arrow, H) do not alter Eda expression.