FIG. 2.

Patterns of methylation in unstimulated and stimulated cells. The panels are fluorographs of sodium dodecyl sulfate-polyacrylamide gels loaded with samples of ³H-methyl-labeled cells containing the indicated protein as the sole detectable chemoreceptor. Only the segments of the fluorographs including the labeled chemoreceptors are shown. Cells were mixed with buffer, 10 mM ribose, or 10 mM serine. Exposure times were 100 h for the top panels, corresponding to genes with trg-derived 5′ segments, and 5 h for the bottom panels, corresponding to genes with tsr-derived 5′ segments.