FIG 5.

Transcriptional activation of the fusA2 gene by the BT4338 protein is required for colonization of the murine gut. Shown are the abundances of wild-type B. thetaiotaomicron (GT478), a BT4338-deficient strain (WH150), a fusA2-deficient strain (WH148), and a strain lacking the 22-bp BT4338 binding site in the fusA2 promoter (Δ22bp; WH324) at the indicated times after gavage of all four strains into germfree mice. The abundance of each strain was measured by qPCR of unique molecular barcodes. Data represent averages for 5 individual mice, and error bars represent SEM. A log₁₀ scale is used for the y axis.