Ultrastructural Analysis of the Midgut of Drosophila auraria larvae—Distribution of Alkaline Phosphatase, Acid Phosphatase, Leucine Aminopeptidase, and Glycogen

Abstract

Anatomically, the insect midgut is the largest, and, functionally, the most important section of the digestive tract of insects. Its function is accomplished by the secretion of digestive enzymes which, in some species, is complemented by the secretion of amylase by the salivary glands which are mixed with the foodstuffs before the latter are ingested (Agrawal and Bahadur 1978, Hansen Bay 1978). The anterior midgut, along with the gastric caeca, have been considered as important regions for the uptake of water, ions and nutrients (Wigglesworth 1933, Ramsay 1950, Treherne 1967, Berridge 1970). Specifically in D. melanogaster, the posterior midgut has been considered responsible for nutrient absorption, while the anterior and the middle midgut for the secretion of digestive enzymes (Strasburger 1935, Bodenstein 1950). In this paper, we report ultrastructural histochemical data concerning the localization of certain enzymes as well as of glycogen in the various regions of the larval midgut of D. auraria, which are important for the above mentioned processes. © 1985, Japan Mendel Society, International Society of Cytology. All rights reserved.