Active Hair Growth Is Fuelled by Conveyor-Belt Like Differentiation of Germinative Layer Cells

The study "Active hair growth is fuelled by conveyor-belt like differentiation of germinative layer cells" uses single-cell RNA-sequencing, single-molecule mRNA FISH, and in vivo lineage-tracing experiments to explore how matrix progenitor cells, also known as germinative layer cells, coordinate hair growth and commit to specific lineages. The researchers found that these cells dynamically relocate in a conveyor-belt-like movement from the bottom to the top of the dermal papilla, changing their lineage fate and gradually restricting their potential the closer they get to the dermal papilla-top located medulla niche. This process is characterized by a gradual change of expression from Lgr5 in the lower proximal cup, through Dcn, Id3 and Msx1 in the central part, to distal Lef1 expression where the medulla lineage starts. This study provides a detailed understanding of how matrix progenitor cells differentiate into inner hair follicle layer subtypes according to their location on this conveyor belt.