CYTOCHEMICAL ELECTRON MICROSCOPY ON POLYSACCHARIDE GRANULES IN THE ENDOGENOUS FORMS OF EIMERIA BRUNETTI

Abstract

The endogenous stages in the life cycle of Eimeria brunetti were tested for polysaccharide material by electron microscopical cytochemistry using the periodic acid‐thiocarbohydrazideosmium tetroxide (PATO)‐method. The parasites were observed within the epithelial cells of the small intestine of infected domestic fowls. Two types of granules reacted positively for polysaccharide. The first was large, approximately 500 nm by 250 nm. These granules had an appearance similar to the polysaccharide granules reported for other coccidian parasites. They were observed in mature merozoites, macrogamonts, and developing oocysts. The second type of granule was smaller (15–30 nm in diameter) and was only observed at the periphery of the residual cytoplasmic mass of mature microgamonts. It was more similar in appearance to metazoan glycogen than the former. However, since the PATO‐method does not differentiate between different polysaccharides it can not be proven if these granules in fast contain glycogen. The WFB I of the macrogamete and the outer layer of the oocyst wall gave a slight positive reaction but after examination of the controls it appeared that this was not a specific reaction for polysaccharides.

The fine structure of sexual stage development and sporogony ofCryptosporidium parvumin cell-free culture

“…Homologs of this cysteine-rich oocyst wall protein were also found in other apicomplexan parasites, such as Toxoplasma gondii (Templeton et al 2004) and Gregarina niphandrodes (Omoto et al 2004). The presence of amylopectin granules with finely stained natural content within the developing oocysts shown by our data is supported by other studies on C. parvum (Harris et al 2004) and other coccidians (Ferguson et al 1977). The three electron-dense layers with the intermediate electron-translucent layer of the TKW oocysts identified here are identical to micrographs observed in previous studies on purified oocyst walls viewed by negative staining or thin sectioning EM (Reduker et al 1985 a ; Harris and Petry, 1999; Jenkins et al 2010).…”

Hypoxia-induced GBE1 expression promotes tumor progression through metabolic reprogramming in lung adenocarcinoma

“…The specific staining of polysaccharides was performed using the periodic acid-thiocarbohydrazide-osmium tetroxide (PATO) method 47 . Transmission electron microscopy staining for the PATO method revealed stained electron-dense deposits in the cytoplasmic structures.…”