Figure 4
Hair growth in C57BL/6 mice after intradermal administration of AdShh during first telogen. AdShh, AdNull, or PBS was administered to the dorsal skin of postnatal day 19 C57BL/6 mice. Five days after administration, dorsal hair was bleached with blonde hair dye to provide contrast for assessing new growth of the natural black hair of the mice. On day 7, the dorsal hair was clipped. (a and b) Mice at day 7 after administration of AdShh. Shown are 2 example pairs. The injection site in AdNull-treated animals was indistinct (left-side mice), whereas melanogenesis was evident at the site of AdShh injection in AdShh-treated mice (right-side mice). (c and d) Mice at day 14 after administration of AdShh. Shown are 2 example pairs. The injection site in AdNull-treated animals was indistinct (left-side mice). New hair growth is seen (note black color relative to preexisting dyed hair) at the site of AdShh injection (right-side mice). (e) Lateral aspect of day 14 AdShh-treated mouse showing length of hair growth at injection site. (f) High magnification of injection site showing new black hair and preexisting blonde-dyed hair. Scale bar: 2 mm. (g) Scanning electron microscopic analysis of normal C57BL/6 mouse hair shaft. (h) Scanning electron microscopic analysis of C57BL/6 mouse hair shaft induced by intradermal injection of AdShh (day 14 after vector administration). Scale bar: 10 μm. (i) Spatial distribution of transgene expression. Adβgal (108 PFU), an E1–E3– Ad vector expressing the Escherichia coli βgal marker gene, was injected intradermally on the dorsal surface of postnatal day 19 C57BL/6 mice. On day 0 and on day 2, a single strip of dorsal skin along the cephalocaudal axis was harvested, divided into 5 equal 2.5-mm segments (see diagram below graph; 0 = site of infection), and assayed for βgal activity (data from 3 animals are shown). The gray area corresponds to the size and position of the wheal (7–10 mm in diameter) formed at the site of injection. Data are expressed as βgal activity per mg protein. The anatomic distribution of the marker gene is similar to that of the melanogenesis and new hair growth observed in b and c.
