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Observations on the musculature and isolated muscle fibres of the liver fluke, Fasciola hepatica

Published online by Cambridge University Press:  17 October 2003

D. KUMAR ,
J. G. McGEOWN ,
O. REYNOSO-DUCOING ,
J. R. AMBROSIO  and
I. FAIRWEATHER
D. KUMAR
Affiliation:
Parasite Proteomics and Therapeutics Research Group, School of Biology and Biochemistry, The Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar – 243 122 (UP), India
J. G. McGEOWN
Affiliation:
Smooth Muscle Research Group, Department of Physiology, The Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland
O. REYNOSO-DUCOING
Affiliation:
Department of Microbiology and Parasitology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico 04510
J. R. AMBROSIO
Affiliation:
Department of Microbiology and Parasitology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico 04510
I. FAIRWEATHER
Affiliation:
Parasite Proteomics and Therapeutics Research Group, School of Biology and Biochemistry, The Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland
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Abstract

The liver fluke, Fasciola hepatica relies on a well-developed muscular system, not only for attachment, but for many aspects of its biology. Despite this, little is known about the system beyond the gross organization of the main somatic muscle layers. In the present study, a range of techniques have been applied to F. hepatica in order to understand more about various aspects of muscle organization, biochemistry (in terms of muscle proteins) and identity of isolated muscle fibres. Scanning electron microscopy has provided a direct visualization in situ of the somatic muscle layers and the organization of the muscle fibres within the ventral sucker. The muscle bundles contributing to the main somatic muscle layers are made up of up to 10 individual muscle fibres. Phalloidin staining for actin, in conjunction with confocal microscopy, confirmed the presence of 2 main somatic muscle layers (outer circular, inner longitudinal), beneath which lies a third layer of oblique muscle fibres. The use of propidium iodide in combination with phalloidin staining for actin demonstrated that the cell bodies associated with the 2 main somatic muscle layers are situated beneath the longitudinal muscle layer and are connected to their respective muscle fibres by short cytoplasmic processes. Myosin immunoreactivity was demonstrated in the somatic muscle layers and in the muscle layers surrounding various organ systems within the fluke. Double labelling for actin and myosin confirmed the co-localization of the 2 muscle proteins in the muscle fibres of the ventral sucker. Muscle fibres from the somatic muscle layers and the ventral sucker have been isolated and images obtained with phase-contrast microscopy and scanning electron microscopy. The muscle fibres contain actin and myosin, but lack a nucleus, the connection with the cell body having been broken during the isolation procedure.

Keywords

Fasciola hepaticamusculatureisolated muscle fibresactinmyosinelectron microscopyimmunocytochemistry
Type
Research Article
Information
Parasitology , Volume 127 , Issue 5 , November 2003 , pp. 457 - 473
Copyright
2003 Cambridge University Press

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