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The functional significance of scolex retraction and subsequent cyst formation in the cysticercoid larva of Hymenolepis microstoma

Published online by Cambridge University Press:  06 April 2009

Jennifer Caley
Jennifer Caley
Affiliation:
Department of Zoology and Comparative Physiology, University of Birmingham, P.O. Box 363, Birmingham B15 2TT
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Extract

The cysticercoid type of larval development, involving the retraction of the scolex and the associated development of a cyst, is of widespread occurrence within cyclophyllidean cestodes, but previously its possible adaptive value has been unexplained. Scolex retraction in Hymenolepis microstoma is an active, muscular process which takes only about a minute to complete. Following its retraction the scolex develops adult structures. The cyst enclosing the scolex also differentiates further, involving the secretion of three layers of collagen fibres and the development of a myelin-like layer adjacent to the retracted scolex. The cells within the cyst, including the muscle, become condensed or are autolysed causing a decrease in thickness of the cyst and an increase in the proportion of fibrous tissue. The collagenous part of the cyst provides mechanical protection for the scolex during grinding by the teeth on entry into the mouse host. The myelin-like layer insulates the scolex from the low pH conditions of the stomach. Values of lower than pH 3·0 are lethal to newly excysted worms. The myelin-like layer loses its insulatory capacity following exposure to bile salts.

Type
Research Article
Information
Parasitology , Volume 68 , Issue 2 , April 1974 , pp. 207 - 227
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Ashhurst, D. E. (1968). Fibroblasts—Vertebrate and Invertebrate. In Cell Structure and its Interpretation (eds. McGee-Russell, S. M. and Ross, K. F. A.). London: Edward Arnold Ltd.Google Scholar
Baron, P. J. (1971). On the histology, histochemistry and ultrastructure of the cysticercoid of Raillietina cesticillus (Cestoda: Cyclophyllidea). Parasitology 62, 233–45.Google Scholar
Béguin, F. (1966). Étude au microscope electronique de la cuticle et do ses structures associées chez quelques cestodes. Essai d'histologie comparée. Zeitschrift für Zellforschung und mikroskopische Anatomie 72, 30–46.CrossRefGoogle Scholar
Farquhar, M. G. & Palade, G. E. (1965). Cell junctions in amphibian skin. Journal of Cell Biology 26, 263–91.CrossRefGoogle ScholarPubMed
Freeman, R. S. (1952). The biology and life history of Monoecocestus Beddard, 1914 (Cestoda: Anoplocephalidae) from the porcupine. Journal of Parasitology 38, 111–29.CrossRefGoogle ScholarPubMed
Green, J. A. (1960). Digestion of collagen and reticulin in paraffin sections by collagenase. Stain Technology 35, 273–6.Google Scholar
Humason, G. L. (1967). Animal Tissue Techniques, 2nd ed. London: W. H. Freeman.Google Scholar
Lee, D. L. (1966). The structure and composition of the helminth cuticle. Advances in Parasitology 4, 187–254.CrossRefGoogle ScholarPubMed
Lingard, A. M. & Crompton, D. W. T. (1972). Observations on the establishment of Polymorphus minutus (Acanthocephala) in the intestines of domestic ducks. Parasitology 65, 159–65.Google Scholar
Lumsden, R. D. & Byram, J. (1967). The ultrastructure of cestode muscle. Journal of Parasitology 53, 326–42.Google Scholar
Lyons, K. M. (1969). The fine structure of the body wall of Gyrocotyle urna. Zeitschrift für Parasitenkunde 33, 95–109.Google Scholar
Manton, I. (1964). The possible significance of some details of flagellar bases in plants. Journal of the Royal Microscopical Society 82, 279.Google Scholar
Millonig, G. (1962). Further observations on a phosphate buffer for osmium solutions in fixation. Proceedings of the 5th International Conference of Electron Microscopy 2, Sect. P 8.Google Scholar
Morgan, J. F., Morton, H. J. & Parker, R. C. (1950). Nutrition of animal cells in tissue culture. I. Initial studies on a synthetic medium. Proceedings of the Society for Experimental Biology and Medicine 73, 1–8.Google Scholar
Pearse, A. G. E. (1960). Histochemistry, Theoretical and Applied, 2nd ed. London: J. and A. Churchill, Ltd.Google Scholar
Pedersen, K. J. (1966). The organisation of the connective tissue of Discocelides langi (Turbellaria: Polycladida). Zeitschrift für Zellforschung und mikroskopische Anatomie 71, 94–117.Google Scholar
Rees, F. G. (1973 a). Cysticercoids of three species of Tatria (Cyclophyllidea: Amabiliidae) including T. octacantha sp.nov. from the haemocoele of the damsel-fly nymphs Pyrrhosoma nymphula, Sulz and Enallagma cyathigerum, Charp. Parasitology 66, 423–6.CrossRefGoogle Scholar
Rees, F. G. (1973 b). The ultrastructure of the cysticercoid of Tatria octacantha Rees, 1973 (Cyclophyllidea: Amabiliidae) from the haemocoele of the damsel-fly nymphs Pyrrhosoma nymphula, Sulz and Enallagma cyathigerum, Charp. Parasitology 67, 83–103.Google Scholar
Reynolds, E. S. (1963). The use of lead citrate at high pH as an electron opaque stain in electron microscopy. Journal of Cell Biology 17, 208–11.Google Scholar
Ross, R. & Bornstein, P. (1971). Elastic fibres in the body. Scientific American 224, 44–52.Google Scholar
Rothman, A. H. (1959). Studies on the excystment of tapeworms. Experimental Parasitology 8, 336–64.CrossRefGoogle ScholarPubMed
Stempak, J. G. & Ward, R. J. (1964). An improved staining method for electron microscopy. Journal of Cell Biology 22, 697–701.Google Scholar
Threadgold, L. T. & Gallagher, S. S. E. (1966). Electron microscope studies of Fasciola hepatica. I. The ultrastructure and interrelationship of the parenchyma cells. Parasitology 56, 266–304.Google Scholar
Ubelaker, J. E., Cooper, N. B. & Allison, V. F. (1970). The fine structure of the cysticercoid of Hymenolepis diminuta. Zeitschrift für Parasitenkunde 34, 258–70.CrossRefGoogle ScholarPubMed
Voge, M. (1963). Studies in cysticercoid histology. VII. Observations on the fully developed cysticercoid of Hymenolepis microstoma (Cestoda: Cyclophyllidea). Proceedings of the Helminthological Society of Washington 30, 67–70.Google Scholar
Voge, M. (1964). Development of Hymenolepis microstoma (Cestoda: Cyclophyllidea) in the intermediate host Tribolium confusum. Journal of Parasitology 50, 77–80.CrossRefGoogle ScholarPubMed
Voge, M. (1967). The post-embryonic developmental stages of cestodes. Advances in Parasitology 5, 247–98.Google Scholar
Waele, A. De (1933). Recherches sur les migrations des cestodes. III. Sur le méchanism de l'infection de l'hôte définitif par la larve. Expériences sur le type cysticerque. Bulletin de l'Académie royale de Belgique. Classe des Sciences 19, 1126–35.Google Scholar
Waele, A. De (1934). Recherches sur les migrations des cestodes. IV. Étude de l'infection de l'hôte définitif par une larve du type cénure. Bulletin de l'Académie royale de Belgique. Classe des Sciences 20, 910–21.Google Scholar
Waele, A. De & Dedeken, L. (1936). Le phénoménon de l'évagination chez Cysticercus bovis et la migration du parasite chez l'homme. Mémoires du Musée royale d'histoire naturelle de Belgique 2, 369–73.Google Scholar