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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Cryoelectron Microscopy, Electron Microscope Tomography, Imaging, Three-Dimensional, Intracellular Membranes, Merozoites, Microscopy, Electron, Transmission, Plasmodium berghei, Plasmodium falciparum, Plastids.
user
Does cryo-electron tomography reveal four-membrane architecture of the Plasmodium apicoplast? Context: The apicoplast is a plastid organelle derived from a secondary endosymbiosis, containing biosynthetic pathways essential for the survival of apicomplexan parasites. The Toxoplasma apicoplast clearly possesses four membranes but in related Plasmodium spp. the apicoplast has variably been reported to have either three or four membranes. Cryo-electron tomography was employed to image merozoites of Plasmodium falciparum and Plasmodium berghei frozen in their near-native state. Three-dimensional reconstructions revealed the number of apicoplast membranes and the association of the apicoplast with other organelles. Routine transmission electron microscopy of parasites preserved by high-pressure freezing followed by freeze substitution techniques was also used to analyse apicoplast morphology. Cryo-preserved parasites showed clearly four membranes surrounding the apicoplast. A wider gap between the second and third apicoplast membranes was frequently observed. The apicoplast was found in close proximity to the nucleus and to the rhoptries. The apicoplast matrix showed ribosome-sized particles and membranous whorls.
assistant
The Plasmodium apicoplast possesses four membranes, as do the apicoplasts of other apicomplexan parasites. This is consistent with a four-membraned secondary endosymbiotic plastid ancestor. Final Decision: yes