FIG. 3.
Acute effects of UV-B on the skin of XpbXPCS mice. H&E staining of dorsal skin sections from shaven mice exposed to daily doses of 500 J/m2 UVB for four consecutive days and sacrificed 1 week after the start of the treatment. Note the moderate epidermal hyperplasia, consisting of an increased number of cell layers (acanthosis, indicated with a bar) in the XpbXPCS skin and the much more severe effect in Xpa mice as evident from hyperemia (dilated capillaries filled with blood, indicated with a long arrow) and the absence of keratinized and epidermal layers (asterisk), reflecting severe “scaling of the skin.” Note the “swelling” of the nuclei after UV treatment in all genotypes compared to untreated controls (short arrows). Magnification, ×400.