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Salivary glands of the tsetse Glossina pallidipes Austen infected with Trypanosoma brucei and virus particles: Ultrastructural study

Published online by Cambridge University Press:  19 September 2011

E. D. Kokwaro
Affiliation:
The International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya
L. H. Otieno
Affiliation:
The International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya
M. Chimtawi
Affiliation:
The International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya
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Abstract

The effects of infection by Trypanosoma brucei and DNA virus on the ultrastructure of the salivary gland cells in Glossina pallidipes Austen were investigated. Cytoplasm of uninfected cells contains a dense ribosomal population and rough endopiasmic reticulum, scattered Golgi areas and mitochondria. In infected ceils of salivary glands the ultrastructural integrity of the cytoplasm is profoundly changed due to cellular proliferation giving rise to a stratified epithelium and gland enlargement; cell degeneration characterized by formation of cytoplasmic vacuoles, chromatin margination, disorganization and elimination of cell organelles and gland hypertrophy. The virus particles are found in the nucleoplasm as well as the cytoplasm of cells. The ultrastructural evidence indicates that the virus are largely assembled in nuclei of cells and virions pass through the nuclear membrane. The trypanosomes are found within the degenerating cytoplasm and lumen of the cell.

The implications of the features observed in the infected cells are discussed, and possible suggestions are made regarding alteration of the metabolic functions due to infection.

Résumé

Les effets de l'infection due aux Trypanosoma brucei et au DNA-virus sur l'ultrastructure des cellules de glandes salivaires des Glossina pallidipes Austen furent analysée. Le cytoplasme des cellules non-infecté contient une population dense de ribosomes et un reticulum endoplasmique rugeux, des surfaces de Golgl et de mitochondries eparpilles. Chez les cellules infectées l'integral de l'ultrastructure du cytoplasme est profondement changée grâce à une prolifération celluiaire donnant naissance à un epithelium stratifié et à une hypertrophie de la glande; dégéneration cellulaire characterisée par la formation des vacoules cytoplasmiques, marginalisation de la chromatine, désorganisation et élimination de la substance celluiaire et hypertrophie de la glande. Les particules virales se trouvaient dans le nucleoplasme ainsi que dans le cytoplasme des cellules. L'évidence ultrastructurale indique que les virus sont asemblées dans le noyeau celluiaire et que le virion passe à travers la membrane nucleaire. Les trypanosomes ont été trouvé dans le cytoplasme en dégéneration.

Les implications de ces observations dans les cellules infectées ont été discuté et des suggestions ont été faites en ce que regarde l'alterations des fonction metaboliques due à l'infection.

Type
Part II: Symposium on Insect Pests and Sustainable Food Production: Insect Physiology
Copyright
Copyright © ICIPE 1991

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