the body and the environment. The main epidermal cell type is an epithelial cell, the keratinocyte.The major structures of the epidermis are the interfollicular epidermis (IFE), hair follicles (HFs), sweat glands, and sebaceous glands (SGs). In human epidermis, the sweat glands are present in both hair-bearing and hairless regions, whereas in mouse epidermis, the sweat glands are restricted to ...

According to a recent model, the cortical tractor model, neural fold and neural crest formation occurs at the boundary between neural plate and epidermis because random cell movements become organized at this site. If this is correct, then a fold should form at any boundary between epidermis and neural plate. To test that proposition, we created new boundaries in axolotl embryos by juxtaposing ...

Many investigators have reported on the fine structure of the boundary between dermis and epidermis, but their results were different from one another. Herxheimer (1916), working on the normal and abnormal human skin, pointed out that the cytoplasmic processes of the epithelial cell project toward the dermis and they are intimately associated with the translucent basement membrane which exists ...

Elongation of the epidermis of the nematode Caenorhabditis elegans involves both actomyosin-mediated changes in lateral epidermal cell shape and body muscle attachment to dorsal and ventral epidermal cells via intermediate-filament/hemidesmosome structures. vab-19 mutants are defective in epidermal elongation and muscle attachment to the epidermis. VAB-19 is a member of a conserved family of an...

Transcripts of exclusively epidermis-specific expression were obtained by differential screening of a cDNA library prepared from isolated epidermis tissue of a succulent plant, Pachyphytum. Six transcripts were selected and characterized by RNA gel blot hybridization. Five cDNAs represented abundant mRNAs found exclusively in the epidermis. In situ hybridizations with three of these transcripts...

The intraepidermal innervation of the snout skin of the opossum has been studied with the light and electron microscope. Numerous large nerve fibers loose their myelin sheath in the superficial dermis and pass into the epidermis. The basement membranes of the epidermis and Schwann cell become continuous at the point of entry of the neurite into the epidermis. Within the epidermis, the neurite i...

1. The capacity of skin constituents to participate in feather and hair morphogenesis has been analysed in chick and mouse embryos. 2. Reconstituted homoand heterospecific skin explants, consisting of epidermis and dermis from both species, were cultured for 8 days on the chorioallantoic membrane of the chick. 3. Recombinants of dorsal 11-5and 125-day mouse epidermis and dorsal 7-day or tarsome...

The migration of cellular extensions is guided by signals from tissues with which they contact. Many axon guidance molecules regulate growth cone migration by directly regulating actin cytoskeletal dynamics. Secreted morphogens control global patterns of cell fate decisions during organogenesis through transcriptional regulation, and constitute another class of guidance molecules. We have inves...

During development, biomechanical forces contour the body and provide shape to internal organs. Using genetic and molecular approaches in combination with a FRET-based tension sensor, we characterized a pulling force exerted by the elongating pharynx (foregut) on the anterior epidermis during C. elegans embryogenesis. Resistance of the epidermis to this force and to actomyosin-based circumferen...

AP1 (jun/fos) transcription factors (c-jun, junB, junD, c-fos, FosB, Fra-1, and Fra-2) are key regulators of epidermal keratinocyte survival and differentiation and important drivers of cancer development. Understanding the role of these factors in epidermis is complicated by the fact that each protein is expressed, at different levels, in multiple cells layers in differentiating epidermis, and...