FIG. 8.

Ethidium bromide-stained gel (left panel) and corresponding Northern blot (right panel) of total RNA isolated from S. mutans DC10, a PTS mutant. Cells were grown in CDM supplemented with glucose to early logarithmic phase (lane 1), mid-logarithmic phase (lane 2), late logarithmic phase (lane 3), and stationary phase (lane 4). Hybridization was carried out with a radiolabeled dlt1-specific PCR product as the probe. Note that expression of the S. mutans dlt genes is constitutive for all phases of growth. A unique transcript (>10 kb) which is expressed only during early logarithmic phase is designated by the arrow.