Figure 2

MyHC-like molecules are developmentally regulated in skin. Cryosections of P1 rat back skin was reacted with A4.840 (A), N3.36 (B), A4.74 (C), N2.261 (D) or N1.551 (E) and the antibody detected by peroxidase immunohistochemistry. Hair follicles were sectioned longitudinally, as illustrated diagramatically (F). A4.840 labelled all upper layer epidermal cells, whereas N3.36 labelled only some basal cells of the surface epidermis and an outer layer of the hair bulb. A4.74 labelled part of the root sheath at the base of the hair shaft. N2.261 detected the whole basal layer of surface epidermis, but not the hair follicle. N1.551 labelled only a small group of cells on one side of the neck of the hair bulb (arrow, E). Muscle (mus) showed the expected MyHC immunoreactivity for this stage of development. Dermis (D), surface epidermis (SE), basal epidermis (BL), inner root sheath (IRS), outer root sheath (ORS) and dermal papilla (DP). All panels same scale. Muscle is visible in panel B and fibres are approximately 25 μm in diameter.