Watching Hair Grow: The Dance of Basement Membranes

Trying to understand how a building grows. It’s tricky without seeing the scaffold change and move. Similarly, scientists have been puzzled by how mammal hair follicles develop because they couldn’t clearly observe the basement membrane (BM)—the structure that supports and shapes the follicle. To solve this riddle, researchers created a special mouse model with a glowing BM. Using this model, they watched the BM in action as new hair follicles formed. They found that the BM expands and changes at different rates in different places. This expansion helps push hair follicle cells to grow and divide in specific ways, shaping the hair follicle. When scientists slowed down the BM's changes, it altered how hair follicle cells behaved and changed the follicle shape. This discovery shows how crucial the BM's dance is in guiding the growth and shape of hair follicles.