Recombinant Eda protein induces supernumerary mammary placodes and upregulates NF-κB reporter expression ex vivo.

(A-D) Stereomicroscope images of E12.5 flank skins of WTC57BL/6 (n = 11) (A), K14-Eda (n = 15) (B), WTNMRI (n = 21) (C) and WTNMRI supplemented with 250 ng/mL of Fc-Eda (n = 42) (D) cultured for two days ex vivo. A and C are control littermates of B and D, respectively. Ectopic buds were observed in 0/32 control, 15/15 K14-Eda, and 38/42 Fc-Eda treated explants. (E-F) NF-κB reporter expression was analysed in E12.5+1d and E12.5+2d explants cultured in the control medium (E) and medium supplemented with 250ng/mL of Fc-Eda (F), by X-gal staining. (Scale bar: 100 μm.)