Microstructure of muscles in cercariae of the digenetic trematodes Schistosoma mansoni and Tetrapapillatrema concavocorpa
Apparent structural periodicity along the muscle fibers of the cercaria of Schistosoma mansoni (Digenea: Anepitheliocystidia: Schistosomatidae) stimulated the study of the ultrastructure of muscles in this stage of the life history of the Trematoda. Classic investigations (e. g. (1)] have demonstrated an outer circular, an intermediate longitudinal, and, in various species, an inner layer of diagonally oriented muscle fibers in the subcuticula of trematodes. Specialized musculature present in the suckers, and tails of the cercariae are derived from these layers. Myocytes were found to be bipolar, with myofibrillae in the polar processes, and multipolar, with simple or multibranced protoplasmic strands extending from the bodies of the myocytes to relatively distant, otherwise separate myofibrillae. More recently, striated myofibrillae “with areas corn-parable to the Z-line, J-disk, and Q-disk” (2) recognized in striated muscles of some other animals have been reported. Exellent studies of the ultrastructure of the striatet muscles of vertebrates (4, 5, 6) have facilitated the present interpretations.
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- 1.Bettendorf, H.: Zool. Jahr. Abt. Anat. u. Ont. 10, 307 (1897).Google Scholar
- 3.Vatter, A. E., and R. S. Wolfe: J. Bacteriol. 75, 480 (1958)Google Scholar
- 4.Andersson, E.: Proc. Stockholm Conf. Elec. Micr. 1956. New York: Acad. Press Inc. p. 208, 1957.Google Scholar
- 5.Sjöstrand, F. S., and E. Andersson: Proc. Stockholm Conf. Elec. Micr. 1956. New York: Acad. Press Inc. p. 204, 1957.Google Scholar
- 6.Porter, K. R., and G. E. Palare• J biophys. biochem. Cytol. 3, 269 (1957).Google Scholar