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- Endocytobiosis and ...
- Volume 2
- Issue 3
- Ultrastructural asp...
- Autor(in)
- Seitenbereich
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139 - 158
- Zusammenfsg.
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Beside normal endocytobionts, structures that might be regarded as degenerating bacteria could be observed in mycetocytes. There were often exfoliating membranes as well as concentric membranous figures in the bacteriophoric vacuoles that surrounded the endocytobionts. The accumulation of membranes occurred both around endocytobionts and around concentric figures. It was possible to watch a row of transition stages of the formation of round or oval myelin-like figures (up to 5 u in size) situated both inside as well as outside the bacteriophoric vacuoles. Comparatively rare were large (up to 10 μ) configurations with electronoptically alternating dense and light layers with a period of 50 A. Near the endocytobionts of the third type multivesicular structures were found. In the cytoplasm of neighbouring cells no such myelinlike organised structures were found, which indicates their specificity. The ultrastructural peculiarities of the bacteriophoric vacuoles indicate their functional activity in such interconnections of pro- and eukaryotic cells. The existence of myelin-like figures we may regard as some evidence of the fact that the host is probably able to regulate the number of endocytobionts by digesting them and, in this way, getting the necessary nutritive substances for itself, leaving the residual bodies in the mycetocytes. Another possibility is that these structures represent some kind of intracellular depot of certain substances required by the insect, which are secreted by endocytobionts. Some additional confirmation of the opinion that concentric myelin-like figures are final stages of cellular degeneration consisting mainly of llpoproteids was obtained by treating the sections with phospholipase, pronase and trypsin.
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