Electron microscopy of bacterized and axenic trophozoites of Entamoeba histolytica showed only slight differences in ultrastructure between the two. As with other species of Entamoeba so far studied, this species lacks typical mitochondrial structures and formed endoplasmic reticulum. Dense clusters of glycogen particles are especially characteristic in axenic amebas. Microtubular structures 360 A in diameter appear randomly oriented in both bacterized and axenic trophozoites. Ribonucleoprotein (RNP) bodies are of two typical forms—elongate, parallel arrays of helices (the classical chromatoid bodies), and short helical fragments. Both kinds of helix show a recurring pitch angle of 68–80° and an over-all diameter of 480 A. RNP particles comprising the helices average 180 A in diameter. The longitudinal axes of adjacent helices are 440 A apart. Following RNase digestion of water-soluble methacrylate sections, helices show a core approximately 60 A in diameter. Short helices are also associated with digestive vacuoles. Free RNP particles per se are never seen within digestive vacuoles, but intact short helices are frequently detected closely associated with the external membrane of digestive vacuoles. In some cases, continuation of externally intact helical forms could be related to filamentous material within the vacuole. Acid phosphomonoesterase activity could be demonstrated within digestive vacuoles where deposition of reaction product is especially intense on the filamentous material.
Article|
May 01 1970
ULTRASTRUCTURE OF BACTERIZED AND AXENIC TROPHOZOITES OF ENTAMOEBA HISTOLYTICA WITH PARTICULAR REFERENCE TO HELICAL BODIES
Robert M. Rosenbaum,
Robert M. Rosenbaum
From the Department of Pathology, Albert Einstein College of Medicine, New York 10461
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Murray Wittner
Murray Wittner
From the Department of Pathology, Albert Einstein College of Medicine, New York 10461
Search for other works by this author on:
Robert M. Rosenbaum
From the Department of Pathology, Albert Einstein College of Medicine, New York 10461
Murray Wittner
From the Department of Pathology, Albert Einstein College of Medicine, New York 10461
Received:
September 22 1969
Revision Received:
December 15 1969
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Copyright © 1970 by The Rockefeller University Press
1970
J Cell Biol (1970) 45 (2): 367–382.
Article history
Received:
September 22 1969
Revision Received:
December 15 1969
Citation
Robert M. Rosenbaum, Murray Wittner; ULTRASTRUCTURE OF BACTERIZED AND AXENIC TROPHOZOITES OF ENTAMOEBA HISTOLYTICA WITH PARTICULAR REFERENCE TO HELICAL BODIES . J Cell Biol 1 May 1970; 45 (2): 367–382. doi: https://doi.org/10.1083/jcb.45.2.367
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