Regulatory Effects of FGF9 on Dermal Papilla Cell Proliferation in Small-Tailed Han Sheep

The study investigates the role of Fibroblast Growth Factor 9 (FGF9) in hair follicle (HF) growth and dermal papilla cell (DPC) proliferation in small-tailed Han sheep. FGF9 expression varies throughout the HF cycle and significantly influences wool growth. FGF9-treated DPCs exhibited increased proliferation and cell cycle activity, while FGF9 knockdown resulted in the opposite effect. Additionally, FGF9 interacts with the Wnt/β-catenin signaling pathway, suggesting it accelerates DPC proliferation and may regulate HF growth through this pathway. These findings highlight FGF9's potential in hair growth regulation and its possible use in genetically modifying sheep for improved wool production.