Requirement of NF-kappa B/Rel for the development of hair follicles and other epidermal appendices

NF-kappaB/Rel transcription factors and I kappaB kinases (IKK) are essentia l for inflammation and immune responses, but also for bone-morphogenesis, s kin proliferation and differentiation. Determining their other functions ha s previously been impossible, owing to embryonic lethality of NF-kappaB/Rel or IKK-deficient animals. Using a gene targeting approach we have ubiquito usly expressed an NF-kappaB super-repressor to investigate NF-kappaB functi ons in the adult. Mice with suppressed NF-kappaB revealed defective early m orphogenesis of hair follicles, exocrine glands and teeth, identical to Eda (tabby) and Edar (downless) mutant mice.