Effect of the loss of the sRNA BasA on Borrelia burgdorferi gene expression under two in vitro growth conditions
Puprose: The goal of this experiment was to determine if the sRNA BasA regulates borrelial gene expression. Methods: We genetically inactivated BasA in B. burgdorferi B31 5A4 NP1 and complemented BasA into the mutant to then examine gene expression differences due to the loss of BasA. We grew our B. burgdoferi in vitro in both BosR-RpoS uninduced (32ºC, pH 7.6, 1% CO2) conditions and induced (37ºC, pH 6.8, 5% CO2) conditions to mimic the tick phase and mammalian phase of the borrelial enzootic cycle, respectively. These strains were prepared for total RNA sequencing. Results: When the BasA mutant was compared to the parent strain 5A4 NP1, 61 transcripts in uninduced conditions and 103 transcripts in induced conditions were signifcantly dysregulated. The majority of the transcripts dysregulated by the loss of BasA in induced conditions are known to be regulated by B. burgdorferi BosR and RpoS. Conclusions: The sRNA BasA regulates important borrelial virulence factors. Overall design: RNA-seq profiling of B. burgdorferi B31 5A4 NP1, ?BasA, and the ?BasA complement derivatives in both BosR-RpoS uninduced in vitro growth conditions (32ºC, pH 7.6, 1% CO2) and BosR-RpoS induced in vitro growth conditions (37ºC, pH 6.8, 5% CO2).