FIG 2.

Effect of overexpression of lrg or cid on cid or lrg, respectively. The expression of lrgA (A) and cidA (B) was measured at early (OD₆₀₀ = 0.2) and late (OD₆₀₀ = 0.9) exponential growth phases of UA159 (WT), UA159 ΩPldh-lrg, and UA159 ΩPldh-cid strains by qRT-PCR. Expression of cid and lrg genes was constitutively driven by the constitutive ldh promoter of S. mutans in UA159 ΩPldh-lrg and UA159 ΩPldh-cid strains, respectively. Data are averages of three independent biological replicates. Differences in relative gene expression between strains were evaluated for statistical significance by Student's t test. **, P < 0.005.