Fine structure and permeability of the metacercarial cyst wall of Clinostomum marginatum (Digenea)

Omer R. Larson; Gary L. Uglem; Kook J. Lee

doi:10.1007/bf00539457

The Fine Structure of the Cyst Wall of the Metacercaria of Fasciola hepatica

Journal of Cell Science ◽

10.1242/jcs.s3-105.72.385a ◽

1964 ◽

Vol s3-105 (72) ◽

pp. 385-389

Author(s):

K. E. DIXON ◽

E. H. MERCER

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Cyst Wall ◽

Fasciola Hepatica ◽

Fibrous Layer ◽

Protein Layer ◽

Compact Layer

Observations with the electron microscope have shown that 4 major layers can be distinguished in the cyst wall: (a) an outer tanned-protein layer, consisting of a meshwork of irregular bodies made up of cigar-shaped particles; (b) a predominantly mucopolysaccharide, finely-fibrous layer, closely adherent to the tanned layer; (c) an inner, mainly mucopolysaccharide layer, which can be resolved into two layers differing in fine texture; (d) a dense, compact layer, composed of numerous protein sheets stabilized by disulphide linkages. This layer is formed from tightly wound scrolls, developed in intracellular vacuoles, which are unrolled at the surface of the animal after secretion.

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Histochemical characteristics of the metacercarial cyst wall of Gynaecotyla adunca

Journal of Helminthology ◽

10.1017/s0022149x00014176 ◽

1995 ◽

Vol 69 (3) ◽

pp. 223-228

Author(s):

J. Lee ◽

M.A. Medlin ◽

S.T. Dunn

Keyword(s):

Outer Layer ◽

Cyst Wall ◽

Light Microscope ◽

Structural Modification ◽

Microscope Level ◽

Histochemical Analysis ◽

Light Microscope Level ◽

Metacercarial Cyst

AbstractThe cyst wall of the metacercaria of Gynaecotyla adunca (Microphallidae: Digenea) was subjected to comprehensive histochemical analysis. At the light microscope level, a uniformly thick, bipartite cyst wall, probably wholly of parasite origin, was evident. Structural modification of the cyst wall to provide an escape aperture was not apparent. The thicker, inner layer was comprised of phospholipid and glyco- and/or mucoproteins, possibly similar in structure to collagen. The outer layer was highly proteinaceous and contained additional amounts of acidic and neutral mucosubstances. The results are discussed in the context of previous observations regarding the excystment requirements of this microphallid species.

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Evidence for the presence of quinone methide isomerase in the metacercarial cyst of Microphallus sp. (Trematoda: Microphallidae)

Parasitology ◽

10.1017/s0031182000059576 ◽

1991 ◽

Vol 103 (2) ◽

pp. 299-303

Author(s):

K. Nellaiappan ◽

R. Ramakrishnan ◽

M. Jameela Banu

Keyword(s):

Cyst Wall ◽

Quinone Methide ◽

Metacercarial Cyst ◽

White Colour

The white colour of the cyst wall of the metacercaria of Microphallus sp., even in the presence of dihydroxy phenol and phenoloxidase, is due to proteins generated through a possible quinone methide interaction. The quinone methide isomerase converts the phenoloxidase mediated quinone into β-hydroxy catechol. Formation of catechol from quinone by cyst extracts was observed spectrophotometrically and chromatographically. This enzyme is involved in detoxification of excess quinone and β-sclerotization of the cyst wall.

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On the histology, histochemistry and ultrastructure of the cysticercoid of Raillietina cesticillus (Molin, 1858) Fuhrmann, 1920 (Cestoda, Cyclophyllidea)

Parasitology ◽

10.1017/s003118200007147x ◽

1971 ◽

Vol 62 (2) ◽

pp. 233-245 ◽

Cited By ~ 27

Author(s):

P. J. Baron

Keyword(s):

Fine Structure ◽

Cyst Wall ◽

Financial Support ◽

North East ◽

The North ◽

College Of Technology ◽

Histochemical Tests ◽

Electron Microscopes ◽

The University

The structure of the cysticercoid of Raillietina cesticillus has been studied with the aid of light and electron microscopes. While the ultrastructure of the superficial parts of the scolex closely resembles that of other cestodes, the fine structure of the cyst wall differs from both these. The arrangement and functions of the tissues in the cyst wall are discussed and interpreted with reference to the tissues of the scolex of the cysticercoid of R. cesticillus and to the tissues of other cestodes. R. cesticillus cysticercoids, subjected to various histochemical tests, were shown to contain proteins and carbohydrate materials.The author wishes to thank the Principal and Governors of West Ham College of Technology, a constituent college of the North-east London Polytechnic, for their general and financial support of this work. Thanks are also due to the Directors and Governors of the several institutions whose electron microscopes the author used. The work described here forms part of a thesis approved by the University of London for the degree of Ph.D.

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Fine Structure of Posthodiplostomum Minimum Metacercarial Cyst Wall

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072897 ◽

1973 ◽

Vol 31 ◽

pp. 490-491

Author(s):

C. W. Mitchell

Keyword(s):

Cyst Wall ◽

Outer Wall ◽

Digenetic Trematode ◽

Ultrastructural Organization ◽

Fresh Water Fish ◽

Intermediate Hosts ◽

Metacercarial Cyst ◽

Posthodiplostomum Minimum ◽

Water Fish ◽

Host Origin

The metacercaria of the digenetic trematode Posthodiplostomum minimum inhabit the major visceral organs, e.g. liver, kidney or heart, of numerous species of fresh-water fish as second intermediate hosts. These larval trematodes establish a thin cyst wall which is composed of a cellular, outer wall of host origin and an inner, acellular layer of parasitic origin. This report describes some preliminary observations on the ultrastructural organization of the metacercarial cyst wall found within naturally infected sunfish liver.These observations represent the first strigeid cyst studied by electron microscopy. However, cyst structure resembled others encysted within tissues of an intermediate host. A primary wall, apparently secreted by the parasite, prevents host destruction of the metacercaria.

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