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Ultrastructural changes associated with exsheathment of infective juveniles of Haemonchus contortus

Published online by Cambridge University Press:  06 April 2009

D. A. Wharton
D. A. Wharton
Affiliation:
Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand
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Extract

Ultrastructural changes associated with exsheathment of the infective juveniles of Haemonchus contortus are described. Hyaline ring formation occurs associated with annulations 10 and 20 and consists of the dissolution of the basal zone and the inner electron-dense layer resulting in the rupture of the sheath. These changes are consistent with the action of a protease-exsheathing enzyme. There is a significant reduction associated with exsheathment in the size of the excretory cells and the number of excretory granules contained within them. No changes in the oesophagus were observed associated with exsheathment. These, and the observations of earlier workers, suggest that it is the excretory cells and not the oesophagus which are the source of exsheathing fluid during exsheathment.

Keywords

Haemonchus contortustrichostrongylecuticlesheathnematodeexsheathmentultrastructureexcretory celloesophagushyaline ring
Type
Research Article
Information
Parasitology , Volume 103 , Issue 3 , December 1991 , pp. 413 - 420
Copyright
Copyright © Cambridge University Press 1991

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