Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-26T01:13:42.541Z Has data issue: false hasContentIssue false

Schistosoma mansoni: a scanning electron microscope study of the developing schistosomulum

Published online by Cambridge University Press:  06 April 2009

Jean E. Crabtree
Affiliation:
Department of Biology, University of York, York YO1 5DD
R. A. Wilson
Affiliation:
Department of Biology, University of York, York YO1 5DD

Summary

The surface morphology of schistosomula extracted from the skin, lungs and hepatic portal system (hps) of mice was investigated from Days 0 to 18 post-infection. Skin schistosomula and newly arrived schistosomula from the hps were of similar dimensions but were morphologically distinct. Lung schistosomula were considerably elongated with an estimated 53% increase in surface area compared to skin schistosomula. The pitted tegument of lung schistosomula was formed into ridges and troughs. These were compressed together in contracted individuals recovered from the hps on Day 10. The annular ridges were cross-linked by longitudinal septae which possibly prevent further elongation of the body. A regression of the spines between the mouth and the ventral sucker was observed in Day 2 skin schistosomula. In lung schistosomula only the spines at the anterior and posterior of the body remained. New spines were formed after the schistosomula reached the hps. It is suggested that the spines in the mid-region of the body are selectively disassembled and that their loss facilitates migration along the lumina of capillaries with the residual spines acting as anterior and posterior anchors. The mouth opening was enlarged in schistosomula from the hps recovered from Day 10 onwards. Skin schistosomula lost the cercarial apical tegumentary ridges between 24 and 48 h after penetration but a spineless protrusible area remained. After arrival in the hps this area became integrated into the anterior surface as the oral sucker developed around the sub-terminal mouth. The cercarial ciliated papillae were lost on penetration. The migrating schistosomulum had few visible sensory papillae but following arrival in the hps new papillae were observed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Clegg, J. A. (1965). In vitro cultivation of Schistosoma mansoni. Experimental Parasitology 16, 133–47.CrossRefGoogle ScholarPubMed
Clegg, J. A. & Smithers, S. R. (1972). The effects of immune rhesus monkey serum on schistosomula of Schistosoma mansoni during cultivation in vitro. International Journal for Parasitology 2, 7998.CrossRefGoogle ScholarPubMed
Cohen, A. L. (1974). Critical point drying. In Principles and Techniques of Scanning Electron Microscopy, vol. 1 (ed. Hayat, M. A.), pp. 44112. New York: van Norstrand Reinhold Company.Google Scholar
Dorsey, C. H. (1976). Schistosoma mansoni: description of the head gland of cercariae at the ultrastructural level. Experimental Parasitology 39, 444–59.CrossRefGoogle ScholarPubMed
Hockley, D. J. (1968). Scanning electron microscopy of Schistosoma mansoni cercariae. Journal of Parasitology 54, 1241–3.CrossRefGoogle ScholarPubMed
Hockley, D. J. & McLaren, D. J. (1973). Schistosoma mansoni: changes in the outer membrane of the tegument during development from cercaria to adult worm. International Journal for Parasitology 3, 1325.CrossRefGoogle ScholarPubMed
Imohiosen, E. A. E., Sher, A. & von Lichtenberg, F. (1978). Early developmental changes of schistosomula of schistosomula mansoni in vitro and in mouse lung. Parasitology 76, 317–26.CrossRefGoogle ScholarPubMed
Lawson, J. R. & Wilson, R. A. (1980). Metabolic changes associated with the migration of the schistosomulum of Schistosoma mansoni in the mammal host. Parasitology 81, 325–36.CrossRefGoogle ScholarPubMed
Lefebvre, P. A., Nordstrom, S. A., Moulder, J. E. & Rosenbaum, J. L. (1978). Flagellar elongation and shortening in Chlamydomonas. IV. Effects of flagellar detachment, regeneration and resorption on the induction of flagellar protein synthesis. Journal of Cell Biology 78, 827.CrossRefGoogle ScholarPubMed
McLaren, D. J., Clegg, J. A. & Smithers, S. R. (1975). Acquisition of host antigens by young Schistosoma mansoni in mice: correlation with failure to bind antibody in vitro. Parasitology 70, 6775.CrossRefGoogle ScholarPubMed
Miller, P. & Wilson, R. A. (1978). Migration of the schistosomula of schistosoma mansoni from skin to lungs. Parasitology 77, 281302.CrossRefGoogle ScholarPubMed
Miller, P. & Wilson, R. A. (1980). Migration of the schistosomula of Schistosoma mansoni from the lungs to the hepatic portal system. Parasitology 80, 267–88.CrossRefGoogle Scholar
Morris, G. P. (1971). The fine structure of the tegument and associated structures of the cercariae of schistosoma mansoni. Zeitschrift für Parasitenkunde 36, 1531.CrossRefGoogle ScholarPubMed
Nuttman, C. J. (1971). The fine structure of ciliated nerve endings in the cercaria of Schistosoma mansoni. Journal of Parasitology 57, 855–9.CrossRefGoogle Scholar
Rifkin, E. (1971). Interaction between Schistosoma mansoni schistosomules and penetrated mouse skin at the ultrastructural level. In The Biology of Symbiosis, (ed. Cheng, T. C.), pp. 2543. Baltimore, Maryland: University Park Press.Google Scholar
Robson, R. T. & Erasmus, D. A. (1970). The ultrastructure, based on stereoscan observations, of the oral sucker of the cercaria of schistosoma mansoni with special reference to penetration. Zeitschrift für Parasitenkunde 35, 7686.CrossRefGoogle ScholarPubMed
Senft, A. W. & Gibler, W. B. (1977). Schistosoma mansoni tegumental appendages: scanning microscopy following thiocarbohydrazine-osmium preparation. American Journal of Tropical Medicine and Hygiene 26, 1169–77.CrossRefGoogle ScholarPubMed
Short, R. B. & Cartrett, M. L. (1973). Argentophilic ‘papillae’ of Schistosoma mansoni cercaria. Journal of Parasitology 59, 1041–59.CrossRefGoogle Scholar
Smith, J. H., Reynolds, E. S. & von Lichtenberg, F. (1969). The integument of Schistosoma mansoni. American Journal of Tropical Medicine and Hygiene 18, 2849.CrossRefGoogle ScholarPubMed
Smithers, S. R. & Terry, R. J. (1965). The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of adu1ts. Parasitology 55, 695700.CrossRefGoogle Scholar
Stirewalt, M. A. (1974). Schistosoma mansoni: cercaria to schistosomule. Advances in Parasitology 12, 115–82.CrossRefGoogle ScholarPubMed
Voge, M., Price, Z. & Bruckner, D. A. (1978). Changes in tegumental surface during development of Schistosoma mansoni. Journal of Parasitology 64, 585–92.CrossRefGoogle ScholarPubMed
Wheater, P. R. & Wilson, R. A. (1979). Schistosoma mansoni: a histological study of migration in the laboratory mouse. Parasitology 79, 4962.CrossRefGoogle ScholarPubMed
Wilson, R. A., Draskau, T., Miller, P. & Lawson, J. R. (1978). Schistosoma mansoni: the activity and development of the schistosomulum during migration from the skin to the hepatic portal system. Parasitology 77, 5773.CrossRefGoogle Scholar
Wilson, R. A. & Lawson, J. R. (1980). An examination of the skin phase of schistosome migration using a hamster cheek pouch preparation. Parasitology 80, 257–66.CrossRefGoogle ScholarPubMed