TY - JOUR
T1 - Plasmodium simium
T2 - Ultrastructure of erythrocytic phase
AU - Seed, Thomas M.
AU - Sterling, Charles R.
AU - Aikawa, Masamichi
AU - Rabbege, John
N1 - Funding Information:
We gratefully acknowledge the expert technical assistance of Mr. Michael Hale and Mrs. Darlene Brindley. Supported in part by Public Health Service Training Grant (GM-01784), by NIH Research Grants (RR-05384, RR-05737, and Al-10645), and by U.S. Army R&D Command Contract (DADA 17-70-C-006). This is contribution Number 305 from the American National Red Cross Blood Research Laboratory.
PY - 1976/4
Y1 - 1976/4
N2 - An electron microscopic study of Plasmodium simium infections in the squirrel monkey has supplied information on the ultrastructure of erythrocytic trophozoites, schizonts, merozoites, and gametocytes, in addition to an unusual form of host cell pathology. In general, the structural features, as well as certain specialized functions, e.g., hemoglobin ingestion and utilization, nuclear and cytoplasmic division, were found to be similar to those described for other malarial parasites. Some striking features were noted, however. A highly asynchronous mode of merozoite production was observed within single segmenting parasites in spite of the overall developmental synchrony displayed by the population as a whole. Secondly, during parasite segmentation, newly formed merozoites are connected to one another, as well as to the parasitophorous membrane, by periodic surface strands. It is speculated that these interparasite bridges serve as structural support to the segmenting parasite. When merozoites are matured fully, these interconnections break, leaving a uniform array of short surface bristles. In addition, a number of different pathological changes in host cell structure have been noted. Localized surface discontinuities appear in region of infected cells where apical regions of developing or fully mature merozoites are abutted against the plasma membrane. These profiles suggest that these specialized apical regions of the merozoite function in release as well as in host cell penetration. More generalized surface pathology occurs within parasitized erythrocytes in the form of surface blebs, surface clefts, and associated cytoplasmic microvesicles. The severity of this pathology increases as the intraerythrocytic parasite matures. Topographically these altered cells have a "berry-like" surface texture which makes them quite distinctive when viewed by scanning electron microscopy.
AB - An electron microscopic study of Plasmodium simium infections in the squirrel monkey has supplied information on the ultrastructure of erythrocytic trophozoites, schizonts, merozoites, and gametocytes, in addition to an unusual form of host cell pathology. In general, the structural features, as well as certain specialized functions, e.g., hemoglobin ingestion and utilization, nuclear and cytoplasmic division, were found to be similar to those described for other malarial parasites. Some striking features were noted, however. A highly asynchronous mode of merozoite production was observed within single segmenting parasites in spite of the overall developmental synchrony displayed by the population as a whole. Secondly, during parasite segmentation, newly formed merozoites are connected to one another, as well as to the parasitophorous membrane, by periodic surface strands. It is speculated that these interparasite bridges serve as structural support to the segmenting parasite. When merozoites are matured fully, these interconnections break, leaving a uniform array of short surface bristles. In addition, a number of different pathological changes in host cell structure have been noted. Localized surface discontinuities appear in region of infected cells where apical regions of developing or fully mature merozoites are abutted against the plasma membrane. These profiles suggest that these specialized apical regions of the merozoite function in release as well as in host cell penetration. More generalized surface pathology occurs within parasitized erythrocytes in the form of surface blebs, surface clefts, and associated cytoplasmic microvesicles. The severity of this pathology increases as the intraerythrocytic parasite matures. Topographically these altered cells have a "berry-like" surface texture which makes them quite distinctive when viewed by scanning electron microscopy.
KW - Erythrocytes
KW - Gametocytes
KW - Malaria
KW - Merozoites
KW - Monkeys, Squirrel
KW - Plasmodia
KW - Plasmodium simium
KW - Scanning, transmission electron microscopy
KW - Schizonts
KW - Trophozoites
KW - Ultrastructure
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U2 - 10.1016/0014-4894(76)90126-0
DO - 10.1016/0014-4894(76)90126-0
M3 - Article
C2 - 816667
AN - SCOPUS:0017133452
SN - 0014-4894
VL - 39
SP - 262
EP - 276
JO - Experimental parasitology
JF - Experimental parasitology
IS - 2
ER -