Hair Growth Induction: Roles of Growth Factors

The study explored the roles of epidermal growth factor (EGF) and fibroblast growth factor (FGF) in hair growth induction, focusing on their expression and localization in sheep skin. EGF receptors were found on skin epithelia, and an EGF-like protein was detected in fetal epidermis but not in developing wool follicles, later associating with sebaceous glands and the outer root sheath (ORS). This suggests EGF may influence cell differentiation in the ORS. FGF was found in the epidermis, basal lamina, and follicle plugs during morphogenesis, and later in the ORS and follicle bulb, indicating a role in bulb proliferation and fiber growth.