FIG. 7.
Diffusion of methylation-dependent silencing is blocked by exogenous GAL4VP16 but not TBP. GAL4 (lane 3), GAL4VP16 (lane 4), or TBP (lane 5) mRNA was injected into stage VI oocytes. After 16 h, a mixture of templates containing the regionally methylated 11-aprtGal4×5-tkCAT and CMVCAT DNAs was injected (lanes 2 to 5). In lane 1, the injected DNA mixture contained the mock-methylated vector together with CMVCAT. Oocytes were incubated for 16 h, and RNA was extracted and analyzed by primer extension. The upper part of the figure shows a scheme of the regionally methylated 11-aprtGal4×5-tkCAT template.