Ultrastructure of rhoptry development in Plasmodium falciparum erythrocytic schizonts
| Autor: | Ruth E. Fowler, John M. Hopkins, L. H. Bannister, Graham H. Mitchell, Sanjeev Krishna |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Erythrocytes
Rhoptry Vesicle Plasmodium falciparum Coated vesicle Biology Golgi apparatus Cell biology Microscopy Electron symbols.namesake Infectious Diseases medicine.anatomical_structure Organelle Image Processing Computer-Assisted medicine Ultrastructure symbols Golgi cisterna Animals Freeze Fracturing Animal Science and Zoology Parasitology Nuclear membrane |
| Zdroj: | Parasitology. 121:273-287 |
| ISSN: | 1469-8161 0031-1820 |
| DOI: | 10.1017/s0031182099006320 |
| Popis: | Prior to the separation of merozoites from the Plasmodium falciparum schizont, various stage-specific organelles are synthesized and assembled within each merozoite bud. The apical ends of the merozoites are initiated close to the ends of endomitotic spindles. At each of these sites, the nuclear membrane forms coated vesicles, and a single discoidal or cup- like Golgi cisterna appears. Reconstruction from serial sections indicates that this structure receives vesicles from the nuclear envelope and in turn gives off coated vesicles to generate the apical secretory organelles. Rhoptries first form as spheroidal structures and grow by progressive fusion of small vesicles around their margins. As each rhoptry develops, 2 distinctive regions separate within it, an apical reticular zone with electron-lucent areas separated by cords of granular material, and a more homogenously granular basal region. The apical part elongates into the duct, with evidence for further vesicular fusion at the duct apex. The rounded rhoptry base becomes progressively more densely packed to form a spheroidal mass, and compaction also occurs in the duct. Typically, one rhoptry matures before the other. Cryofractured rhoptry membranes show asymmetry in the sizes and numbers of intramembranous particles at the internally- and externally-directed fracture faces. |
| Databáze: | OpenAIRE |
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