The Nude Gene and the Skin

The study investigated the nude gene, later known as foxn1, in nude mice, which caused hairlessness and thymus dysgenesis due to a mutation. Despite normal hair follicle numbers, keratinization defects led to short, bent hair shafts. Treatments with cyclosporine A and recombinant keratinocyte growth factor (KGF) partially restored hair growth, indicating KGF's role in hair follicle function. The gene was expressed in epithelial cells and involved in hair follicle morphogenesis and epidermal differentiation. The study also focused on the Whn gene's role in hair follicle development, highlighting its expression during different hair cycle phases and its involvement in cell growth regulation. Mutations in the nude gene were linked to hair and thymic defects, with Whn modulating the balance between proliferating and differentiating cell populations. The research suggested evolutionary conservation of Whn-like genes, emphasizing their fundamental role in hair follicle biology and potential implications for thymus biology.