Knocking out TbrPPX1 in procyclic forms does not affect cell growth or acidocalcisome distribution. Panel A: Southern blot of knock-out constructs. A1: genomic Southern blot hybridized with a probe for the TbrPPX1 coding region; A2: the same blot hybridized with a probe for neomycin phosphotransferase; A3: same blot hybridized with a probe for hygromycin phosphotransferase. wt: parental strain; -/+: heterozygous knock-out; C2-7 and C2-23: homozygous knock-out clones. A lambda/HindIII size marker is indicated on the left. Black dot: position of the 5414 bp fragment containing the coding sequence for TbrPPX1. Panel B: generation time of wild type cells and the C2-7 and C2-23 clones after recovery from a 30 min incubation in normosmotic (1×) or hypoosmotic (0.8×, 0.4×) PBS buffer. Panel C-E: acidocalcisomal staining of wild type cells (panel C), and TbrPPX1 knock-out clones C2-23 (panel D) and C2-7 (panel E).