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Cellular organization and peritrophic membrane formation in the cardia (Proventriculus) of Drosophila melanogaster
Author(s) -
King David G.
Publication year - 1988
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051960302
Subject(s) - midgut , foregut , endoplasmic reticulum , biology , proventriculus , cuboidal cell , apical membrane , columnar cell , microbiology and biotechnology , apical cell , membrane , cytoplasm , golgi apparatus , ultrastructure , anatomy , septate junctions , brush border , epithelium , vesicle , cell , biochemistry , cell junction , botany , genetics , larva
The peritrophic membrane of Drosophila melanogaster consists of four layers, each associated with a specific region of the folded epithelial lining of the cardia. The epithelium is adapted to produce this multilaminar peritrophic membrane by bringing together several regions of foregut and midgut, each characterized by a distinctively differentiated cell type. The very thin, electron‐dense inner layer of the peritrophic membrane originates adjacent to the cuticular surface of the stomadeal valve and so appears to require some contribution by the underlying foregut cells. These foregut cells are characterized by dense concentrations of glycogen, extensive arrays of smooth endoplasmic reticulum, and pleated apical plasma membranes. The second and thickest layer of the peritrophic membrane coalesces from amorphous, periodic acid‐Schiff‐positive material between the microvilli of midgut cells in the neck of the valve. The third layer of the peritrophic membrane is composed of fine electron‐dense granules associated with the tall midgut cells of the outer cardia wall. These columnar cells are characterized by cytoplasm filled with extensive rough endoplasmic reticulum and numerous Golgi bodies and by an apical projection filled with secretory vesicles and covered by microvilli. The fourth, outer layer of the peritrophic membrane originates over the brush border of the cuboidal midgut cells, which connect the cardia with the ventriculus.