1. Figure S3. Absence of DNA methylation in pre-cancerous thymocytes
(A) COBRA analysis of bisulfite-treated DNA isolated from EGFP-negative [-] or EGFP-positive [+] thymocytes of three EμSR-tTA;Teto-MYC;Teto-Cre;Rosa26LOXPEGFP quadruple transgenic mice at age 21 days. Thymocytes were purified purified as described in Figure 2B and Material and Methods. PCR products for RLGS fragments 3F56, 4B22 and 1F21 were digested with restriction enzyme BstUI and loaded on PAGE gel along with 100 % methylated (SssI treated DNA) control (100%) and normal thymic control (con). Undigested and digested fragments correspond to unmethylated and methylated DNA, respectively.
(B) COBRA analysis of bisulfite-treated DNA isolated from EGFP-negative [-] or EGFP-positive [+] thymocytes of quadruple transgenic mice at day 31 and day 42 after the birth for indicated RLGS fragments.
(C) COBRA analysis of final tumors for indicated RLGS fragments. A B C
100%
con
21 day-old
3F56
4B22
1F21
mouse 1
mouse 2
mouse 3
undigest.
fragment
digest.
fragments
3F56
4B22
3F70
100%
- +
con
mouse 1
31 day-old
42 day-old
undigest.
fragment
digest.
fragments
3F56
1F21
4B22
final tumors
undigest.
fragment
digest.
fragments
Figure S3