Hierarchical patterning modes orchestrate hair follicle morphogenesis

• DOI: 10.1371/journal.pbio.2002117
• Publication Date: 2017-07-11T17:35:56Z
• Authors: James D. Glover; Kirsty L. Wells; Franziska Matthäus; Kevin J. Painter; William Ho; Jon Riddell; Jeanette A. Johan...; Matthew J. Ford; Colin A. B. Jahoda; Vaclav Klika; Richard L. Mort; Denis J. Headon
• Keywords: Morphogen

Two theories address the origin of repeating patterns, such as hair follicles, limb digits, and intestinal villi, during development. The Turing reaction–diffusion system posits that interacting diffusible signals produced by static cells first define a prepattern then induces cell rearrangements to produce an anatomical structure. second theory, mesenchymal self-organisation, proposes mobile can form periodic patterns aggregates directly, without reference any prepattern. Early follicle development is characterised rapid appearance arrangements altered gene expression in epidermis prominent clustering adjacent dermal cells. We assess contributions interplay between self-organisation processes patterning, identifying network fibroblast growth factor (FGF), wingless-related integration site (WNT), bone morphogenetic protein (BMP) signalling interactions capable spontaneously producing pattern. Using time-lapse imaging, we find condensation at follicles locally directed epidermal However, imposing this prepattern’s condition high FGF low BMP activity across entire skin reveals latent capacity undergo spatially patterned absence epithelial direction. This relies on restricted transforming (TGF) β signalling, which serves drive chemotactic patterning when suppressed, but, normal conditions, facilitates movement prepatterned sources FGF. work illustrates hierarchy modes operating organogenesis.