Journal article

Publication year: 1977

Pages: 145-162

Volume number: 88

Issue number: 2

Abstract: 
In some diplopod families the midgut is surrounded by an enveloping cell layer. Basal runners of their perikarya get through the longitudinal and transversal muscle fibers and ramify secondarily before entering the thick basement membrane of the midgut epithelium. The terminal branches of each cell enter into a basal labyrinth of only 1 differentiated midgut cell interlacing intensively with the epithelium in this way. There seem to be open junctions (fusomes) between terminal branches and the midgut cell and therefore an intracellular transport of materials. The enveloping layer is not an epithelium. There are no typical contacts between neighboring cells; each enveloping cell is surrounded by its own thin basement membrane, a common basement membrane does not exist. Enveloping cells of normally nourished individuals are characterized by a large storage of glycogen in the cytoplasm. Besides this are many distinct cytosomes which indicate a significant metabolic activity. Many mitochondria which mostly pushed off towards the cell periphery or lie in the primarily ramifications indicate the same. Close by is the smooth endoplasmic reticulum. Free ribosomes are not rare. The nucleus gives the impression of metabolic activity too; a nucleolus is present. Microtubules arranged parallel to the cell surface in the cortex, especially in the basal ramifications in longitudinal direction can be seen. Though lipids are not stored, these cells may be compared with the chloragoged tissue in annelids or with the liver cells in vertebrates. They seem to accept food from the midgut cells, to digest and release, or store it temporarily, depositing valueless nitrogen containing molecules into the cytosomes. The term liver cell is well chosen. Animals after 14 days without food show significant shrinkage of the liver cells. The plasmalemma is fixed only at certain points to the basement membrane; the extracellular space between them is widened extremely. Glycogen is mostly lost. The contrast of the cell elements if very faint under the EM. Microtubules have disappeared. Cytosomes contrast distinctly, but, seem to be transformed and joined into a few accumulations. This points to mobiliation of the stored glycogen, but could also by symptomatic of degeneration.

Harvard Citation style: SEIFERT, G. and ROSENBERG, J. (1977) FINE-STRUCTURE OF LIVER-CELLS OF OXIDUS-GRACILIS-(CL KOCH, 1847) (DIPLOPODA, PARADOXOSOMATIDAE), 88(2), pp. 145-162

APA Citation style: SEIFERT, G., & ROSENBERG, J. (1977). FINE-STRUCTURE OF LIVER-CELLS OF OXIDUS-GRACILIS-(CL KOCH, 1847) (DIPLOPODA, PARADOXOSOMATIDAE). 88(2), 145-162.