Figure 3
The MyHC-like molecules are evolutionarily conserved and found in a variety of epithelial tissues. Cryosections of P5 rat tail skin (A-C), adult human scalp skin (D-G), P3 mouse back skin (H-J) and adult rat jejunum (K-M) were reacted with A4.840 (A,D,H,K), N3.36 (B,F,I,L), N2.261 (E) or A4.74 (C,G,J,M) and the antibodies detected by peroxidase-based immunohistochemistry. A4.840-antigen is found in all tissues (arrows, A,D,H,K), but is most readily detected in lower suprabasal layers as skin cornifies in the older tissue (arrow, A). N2.261-reactivity was observed in the basal layer of human skin (arrow, E). N3.36-antigen is present in a subset of cells in a single layer in human and rat epidermis (arrows B,F), although neither the dl DBA mice shown nor two other wild type strains (Balb/c, SwissWebster) showed any reaction (I). A4.74-reactivity was found in the inner root sheath of human, rat and mouse hair follicles (arrows, C,G,J). Note that the pigmented hair shaft also appears dark (asterisks, D-J). Dermal muscle provided positive controls for antibody reactivity (arrowheads, H,I). In the gut, A4.840-antigen was present on most surface epithelial cells of both crypt and villus (arrows, K). N3.36 detected an antigen in cells at the base of crypts, similar to Paneth cells in location (arrow L). se, surface epidermis; m, muscle; d, dermis; c, crypt region; v, villus region; sm, smooth muscle. All panels same scale. Muscle is visible in panels H-J and fibres are approximately 30 μm in diameter.