Fig. 4: Amidases are involved in Bt/Bc persistence.
From: Ingestion of Bacillus cereus spores dampens the immune response to favor bacterial persistence
a qRT-PCR analyses of amidase expressions in midguts upon SA-11 or Bc spore acute feeding. UC corresponds to flies fed with water. Results are shown as mean ± SEM. The dots correspond to independent experiments of 10 pooled female flies. b Bacterial load in midguts of PGRP-SC1/2 Δ double mutant or PGRP-LB ΔE mutant 0.5 or 120 h after SA-11 acute feeding with spores. The horizontal axis indicates the mean number of CFUs per midgut. Each dot corresponds to an independent biological replicate where each replicate is the mean of five midguts. c Representative confocal images showing SA-11R/G spore germination in the anterior and posterior midgut of WT (Canton S), PGRP-SC1/2 Δ double mutant or PGRP-LB ΔE mutant flies 6 h after spore acute feeding. DAPI (blue) marks the nuclei. Spores are in red, vegetative cells in green. The yellow fluorescence corresponds to germinating spores (Fig. 2a). d qRT-PCR analyses of AMP expressions in midguts of PGRP-SC1/2 Δ mutants following acute feeding with SA-11 spores. UC corresponds to PGRP-SC1/2 Δ flies fed with water. mRNA levels in unchallenged PGRP-SC1/2 Δ flies were set to 100 and all other values were expressed as a percentage of this value. Results are shown as mean ± SEM. Dots correspond to independent experiments of the mean of 10 pooled female midguts. e SA-11 load in midguts of flies silenced for PGRP-SC2 or PGRP-LB or overexpressing PGRP-SC2 specifically in enterocytes (using the myo1Ats driver) 0.5 or 120 h after acute feeding with spores. The horizontal axis indicates the mean number of CFUs per midgut. Each dot corresponds to an independent biological replicate where each replicate is the mean of five midguts. Error bars represent SEM. Two-sided Student’s t-tests were used to analyze data in a and d. Two-sided Mann–Whitney test was used to analyze data in b and e. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, ns non-significant (P values are provided in the source data file). Source data are provided as a Source Data file.
