Fig 6.

Detection of spirochete burdens in microinjected nymphal ticks before and after feeding, using qRT-PCR. RNA samples were extracted from whole unfed ticks (10 days after injection) and fed ticks (after repletion; 5 to 7 days) and subjected to PCR analysis. The bacterial burdens in ticks were measured by the number of copies of flaB mRNA compared to the number of copies of tick β-actin transcript as previously described (23, 41). The data are presented as the means of relative levels of flaB transcript ± SEM for three groups (each group containing 3 unfed ticks or 4 replete ticks) for each strain (wild type, cheA₂^mut, and cheA₂^com).