Mitochondrial dynamics in oocyst development. (A–C) Live imaging of MitoRed oocysts on day 7 (A) day 10 (B) and day 13 (C) after mosquito infection. (A) Oocyst at day 7 after infection with the left image showing a maximum intensity projection of the mito-mScarlet signal. The right image shows a segmentation of the mito-mScarlet fluorescent signal by thresholding in Arivis software. Scale bar, 4 μm. (C) Two oocysts on day 13 after infection. Images on the right are crops of the mito-mScarlet signal of the image on the left, indicated by the dotted-line areas. Yellow arrowheads indicate mitochondrial organization centers (MOCs). (D) Oocysts at day 13 show beginning MOCs (yellow arrowheads). (E) Oocyst at day 13 show globular mitochondrial signal which could be a sign of unhealthy or dying parasites. (B–E) Scale bars, 10 μm; scale bars crops, 2 μm.