Figure 2.

Effects of mlc mutation on the expression of SPI1-regulatory genes (A) and apparatus/effector genes (B) in S. Typhimurium, as analyzed by primer extension analysis. Total RNA was prepared from SL1344 (lane 1; wild type) and SR1304 (lane 2; mlc⁻ mutant), which were grown to exponential growth phase in LB medium without shaking. Aliquots of 30 μg of total RNA were co-precipitated and annealed with end-labeled primers. Reactions were performed as described in the Materials and Methods section. The products were resolved on a 6% sequencing gel.