Defective terminal differentiation and hypoplasia of the epidermis in micelacking the Fgf10 gene

Here, we characterized the skin and hair phenotype of mice lacking the fibr oblast growth factor 10 gene (Fgf10), a newly identified member of the fibr oblast growth factor family. Histological examination of Fgf10(-/-) newborn mouse skin revealed abnormalities in epidermal morphogenesis, The number o f proliferating cells in the basal layer was decreased, the granular layer was hypoplastic and lacked distinctive keratohyaline granules and tonofibri ls, The expression of loricrin, a marker of epidermal differentiation, was dramatically reduced. Despite the presence of Fgf10 transaipts in normal ha ir follicles, abnormalities of hair development were not observed in Fpf10( -/-)skin, These data suggest that Fgf10 is required for embryonic epidermal morphogenesis but is not essential for hair follicle development. (C) 2000 Federation of European Biochemical Societies, Published by Elsevier Scienc e B.V. All rights reserved.