Fig. 2.

The Dct93 transgenic mouse line can be used to direct oncogene expression to the melanocytic compartment to promote tumor formation, albeit with low penetrance for MYC. a, Relative MYC expression normalized to GAPDH levels by RT–PCR in normal back skin (N) or tumor (T) from mice of the indicated genotypes, each bar represents an individual mouse. Error bars depict SD. b, Specific positive staining (brown) of normal follicular melanocytes in dorsal mouse skin used as a control for S100 immunohistochemistry, counter stain is blue. c, Similar to human melanoma, tumors arising in tail of Dct93; TRE-MYC mice are positive (brown) for the melanoma antigens, S100 and vimentin and negative for the epithelial marker, pan-keratin. Bottom row depicts the same samples just at higher magnification than the top row. (Scale bars: 100 μm)