Antibodies to Toxoplasma in Panamanian Mammals

Abstract

mitochondrion of B. culicies. A study using serial thick sections and high voltage electron microscopy was extended to the trypomastigote form of T. cruzi. The mitochondrion of the trypomastigote form of T. cruzi is a single, unbranched, sausage-shaped structure with a smooth outer surface (Fig. 1). The kinetoplast nucleoid was found at the posterior end of the mitochondrion within a bulbous swelling (Fig. 1, K; 0.25-,um-thick section). A short, fingerlike projection of the chondriome pervades the truncated posterior pole of the cell with the major portion coursing distally through about two-thirds of the cell body, anterior to the kinetoplast. The arrow on Figure 1 indicates a portion of the mitochondrion seen as it courses anteriorly; an equivalent portion is depicted on Figure 2 for comparison. In some specimens (2 of the 6 reconstructed) the mitochondrion had a swelling or enlarged portion other than in the region of the nucleoid of the kinetoplast. These swellings were seen between the kinetoplast and the nucleus; and when the mitochondria were viewed in longitudinal section, they appeared as large mitochondrial masses (Fig. 3, 0.25-,m-thick section). The length of the mitochondrial tube between ion of B. culicies. A study using serial i s and high voltage electron microse tended to the trypomastigote form the kinetoplast and swelling was variable, e.g., Figure 4, a diagrammatic representation, shows the region to be longer than an equivalent region seen in Figure 3. The three-dimensional models generated in this study unequivocally demonstrate the unitary structure of the chondriome. The variations in the form of swellings of the mitochondrion may reflect differing physiological states of the cell or possible morphogenetic activity of the mitochondrion associated with cell division or transformation. The challenge of the morphogenetic aspects of the mitochondrion is at hand, i.e., how does it divide (split, fractionate, etc.) and what does it do during transformation from the reticulated form seen in the epimastigote to the single tubular form seen in the trypomastigote morphotype? The author is indebted to Eva Nohynkova of the Institute of Parasitology of the Czechoslovak Academy of Science, Prague, Czechoslovakia, for her skillful illustrative work of the three-dimensional models and the National Academy of Sciences Exchange Scientists Program. The high voltage microscope, an NIH Biotechnology Resource at the University of Wisconsin, was used for this study. i toplast and swelling was variable, e g., , a diagrammatic representation, shows i to be longer than an equivalent region i ure 3. e-di ensional models generated in this