Summary
Midgut epithelial cells of female Aedes aegypti deriving from 2 different mosquito strains were compared morphometrically. One of the 2 strains was recently isolated from nature (East Africa). The other strain is an old laboratory strain, reared under laboratory conditions for about 30 years.
The quantitative morphological comparison demonstrates, that the ultrastructural composition of the midgut epithelial cells corresponds generally in both strains. It can be shown, however, that in the old strain, compared to the new strain, the organelle amount of midgut epithelial cells is significantly reduced during the first 53 days of the mosquito's life. Parallel to decreased relative volumes of organelles and reduced surface densities of membrane systems an increase in lysosome-like structures is observed. These observations are interpreted as deterioration processes, possibly due to the long rearing in the laboratory. Therefore, care should be taken in the selection of an A.aegypti strain for any quantitative morphological or physiological investigation.
Zusammenfassung
Die Mitteldarmepithelzellen der Weibchen zweier Aedes aegypti- Stämme wurden morphometrisch verglichen. Ein Stamm wurde relativ frisch aus der Natur (Ostafrika) isoliert; der andere ist ein alter Laborstamm, der seit etwa 30 Jahren unter künstlichen Bedingungen gehalten wird.
Der quantitativ morphologische Vergleich zeigt, daß die ultrastrukturelle Zusammensetzung der Mitteldarmepithelzellen in beiden Stämmen im wesentlichen übereinstimmt. Hingegen wird beim Laborstamm mit zunehmendem Alter der Mücken der Anteil der Organellen an den Darmzellen gegenüber dem frischen Stamm signifikant reduziert. Gleichzeitig beobachtet man eine starke Zunahme lysosomaler Strukturen. Diese Vorgänge werden als Degenerationserscheinungen interpretiert, die durch die lange Laborhaltung der Tiere entstehen könnten. Die Auswahl des für quantitativ morphologische oder physiologische Untersuchungen zu verwendenden yA.aegypti-Stammes ist demzufolge von Bedeutung.
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This investigation has partly been supported by the “Swiss National Foundation for Scientific Research”. The authors are indebted to Prof. T.A. Freyvogel, P.D.Dr.P.H. Burri, P. D. Dr. H. P. von Hahn and Dr. W. Rudin for their interest in this study and for their valuable discussions. The technical assistance of Miss Silvia Bleiker and Charlotte Fauser is greatly acknowledged. We would like to thank Mrs. M. Schmid for typing the manuscript.
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Hecker, H., Brun, R. Morphometric differences in midgut epithelial cells between strains of female Aedes aegypti (L.) (Insecta, Diptera). Cell Tissue Res. 159, 91–99 (1975). https://doi.org/10.1007/BF00231998
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DOI: https://doi.org/10.1007/BF00231998