FIG. 6.

Gene expression of known iron-repressed and iron-activated genes during N. gonorrhoeae infection of endocervical cells. Gonococcal gene expression was examined by RT-PCR analysis with equal amounts of total RNA isolated from total and intracellular bacteria collected at different time points of infection (indicated above each lane). The internal fragments of the iron-regulated fur, tonB, tbpA, fbpA, and sodB genes were amplified in addition to the rmp gene, a gene not regulated by the presence or absence of iron. The amplified cDNA fragments isolated by RT-PCR were resolved on a 1% agarose gel in 1× TAE buffer with 0.5 μg of ethidium bromide/ml and then visualized under UV light.