Global DNA methylation level in mammary gland and tumor.

<p><b>(a)</b> Representative pyrograms obtained in LUMA assay of DNA cleaved with <i>HpaII</i>+<i>EcoRI-HF</i> and <i>MspI</i>+<i>EcoRI-HF</i>. <b>(b)</b> Determination of global DNA methylation in mammary gland from all experimental groups along time. <b>(c)</b> Global DNA methylation in tumors from all experimental groups at the end of the assay (246 days). <b>(d)</b> Comparison of global DNA methylation between mammary gland and tumors in each experimental group at 246 days of age. Data shown represent medians of the groups. Full lines connecting groups indicate differences statistically significant (p<0.05); dotted lines indicate differences close to significance (p<0.1).