Figure 1

Structure of the avian skin. Skin is constituted by an epidermis and a dermis separated by the basement membrane. Three layers constitute bird’s epidermis: the basal layer made of undifferentiated basal keratinocytes, the intermediate layer and the cornified layer made of cornified keratinocytes that are fully differentiated. Keratinocytes are rich in lipids and/or lipid droplets. The dermis is a fibrous vascularized structure mainly composed of fibroblasts and of matrix components such as collagen fibers. By analogy to mammals, it is probable that dendritic cells and T-lymphocytes also reside in the dermis. Langerhans cells are present in basal but also intermediate layers of the epidermis. This figure was illustrated by using BioRender.com (Agreement number: XJ26EG35BS).