Fig. 5: Expression levels of genes involved in mitochondrial respiration and formation of cristae in the parasite Amoebophrya across different intracellular stages within its host (the dinoflagellate Scrippsiella acuminata) and in dinospores (extracellular).

Heatmap showing the expression level of genes of the TCA cycle (A) and the OXPHOS (D) pathway of the parasite. See also Fig. S10 and Table S2; (B) Expression levels of genes encoding MiC60 from the MICOS complex (MItochondrial contact site and Cristae Organizing System), and the prohibitin Phb1 and Phb2 genes. C Transmission Electron microscopy (TEM) micrographs showing the internal morphology of the mitochondrion of the parasite at different infection stages. In the cytoplasmic parasite, the electron dense mitochondrion harbored cristae (internal invagination of the inner mitochondrial membrane), which were absent in the mitochondrion of the nuclear trophont parasites (young and mature trophonts). Some vesicles could be observed in the mitochondrion of the mature trophont. Cristae reappeared in the sporont stage where the mitochondrion was substantially developed. The list of genes, their sequences and expression values can be found in Table S2.