Fine structure of the fat body of the female of Calliphora erythrocephala during the first egg-maturation cycle

1974 ◽  
Vol 152 (2) ◽  
pp. 193-217 ◽  
Author(s):  
Ellen Thomsen ◽  
Mathias Thomsen
Author(s):  
Brendan Clifford

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.


1975 ◽  
Vol 21 (6) ◽  
pp. 1257-1263 ◽  
Author(s):  
A. Bar-Zev ◽  
Esther Wajc ◽  
E. Cohen ◽  
Lea Sapir ◽  
S.W. Applebaum ◽  
...  

1971 ◽  
Vol 17 (2) ◽  
pp. 281-289 ◽  
Author(s):  
R. Y. Zacharuk

The ultrastructural changes that occur in the cells of the hypodermis, fat body, Malpighian tubule, midgut, ventral abdominal ganglion, and muscle during mycoses in three species of elaterid larvae infected with Metarrhizium anisopliae are described. The fungus penetrated all the above tissues before host death in most of the larvae examined. In some infected larvae, however, particularly in the smaller individuals or species, only the hypodermal and fat tissues were penetrated before death. Changes in fine structure appear in all the tissues soon after the fungus enters the hemocoel, even when no fungal growths are present near the host cells. In general, there is initially an increase in the number of lysosomes and of endoplasmic reticulum and ribosomes, followed by a vesiculation of the endoplasmic reticulum and of the cristae of the mitochondria and a progressive vacuolation of the cytoplasm. In some tissues the mitochondria increase in number before vesiculation. Glycogen granules and lipid and oil inclusions disappear rapidly during mycosis. Clear, membrane-limited vacuoles become particularly abundant in the Malpighian tubules and the midgut, suggesting increased secretion of fluids into their lumens. At or soon after death, the lysosomes disappear and all the membranous structures of the cells are disrupted, and laminated or whorled bodies of thickened membranes become numerous. Disintegration of all tissues, including muscle and nerve, was extensive in some larvae that were still capable of some sluggish movement before fixation for the study. It is suggested that the fungus incites lysosome production by the host tissues along with the other initial changes observed, and that final disintegration of the host tissues is by a process of autohistolysis.


1969 ◽  
Vol 112 (2) ◽  
pp. 133-138 ◽  
Author(s):  
G. M. Price ◽  
R. J. Kuhr

1. Carbaryl is metabolized more rapidly by fat body of the blowfly larva than by gut, muscle, cuticle or haemolymph. 2. Metabolism of carbaryl by the fat body is affected by the age of the larva, the pH of the incubation medium, and the concentration of magnesium chloride in the incubation medium. 3. Chloramphenicol, 2,4-dinitrophenol and 5-dimethylamino-6-nitro-1,3-benzodioxole (a carbaryl synergist) inhibit carbaryl metabolism by the fat body. 4. Subcellular fractionation of the fat body indicates that the pellet sedimenting at 30000g is the most reactive with carbaryl. 5. Probable metabolites of carbaryl formed by the fat body include the 4- and 5-hydroxy derivatives, and, possibly, the N-hydroxymethyl and 5,6-dihydrodihydroxy derivatives.


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