The Use of Osmium Mixtures in Localizing Ions in Caenorhabditis Elegans

Abstract

Electron microscopy of Caenorhabditis elegans fixed in an aqueous solution of osmium tetroxide mixed with potassium pyroantimonate, silver lactate or lead nitrate revealed the following. Calcium is localised in the median and basal layers of the cuticle, in the myofibrils of the body wall muscle, in mitochondria, and in intestinal cytosomes. Chloride ions are localised in the cortical zone of the cuticle along the apical membrane infoldings of the hypodermal cells and in the ground substance of the cytoplasm and vesicles of intestinal cells. Orthophosphate ions are localised in nucleoli and heterochromatin, in cytosomes of the intestinal cells, infoldings of the external membranes of the hypodermis, and in the intracristal space of mitochondria. Orthophosphates and/or sulphates surround the microvilli of intestinal cells. The results suggest that chloride ion regulation may occur in the hypodermal cells and intestinal cells rather than in the excretory tubules of C. elegans.