Gene expression in wild-type and MT-DNIIR-28 mammary glands. (A) Northern blot analysis. Three Northern blots containing poly(A) RNA pooled from eight mammary glands of each zinc-treated wild-type and MT-DNIIR-28 virgin females were sequentially hybridized to DNIIR, stromelysin-1, gelatinase A, HGF, and IGF-I probes and then analyzed using a Molecular Dynamics PhosphorImager. Hybridization of cyclophilin (1B15) was used to control for loading errors. After normalization to 1B15, stromelysin mRNA levels in transgenics was 90% of the wild-type control; Gelatinase A was at 107%; IGFI was at 108%; HGF was 200%. (B) RT-PCR analysis of HGF expression. RNA from mammary glands from 10-wk-old untreated MT-DNIIR mice or zinc-treated wild-type and MT-DNIIR-28 mice was used for RT-PCR analysis. RNA from four separate mice under each experimental condition was analyzed. HGF expression was normalized to the level of GAPDH expression. Data are shown as the mean percent of HGF expression relative to the wild-type control ± SEM. The increase in HGF expression in the zinc-treated MT-DNIIR-28 mice relative to the wild-type or untreated MT-DNIIR control is statistically significant (MT-DNIIR-28 + zinc versus wild-type + zinc, p = 0.044; MT-DNIIR-28 + zinc versus MT-DNIIR − zinc, p = 0.0154).