Cytochemical localization of enzyme markers inTritrichomonas foetus

Abstract

Cytochemical techniques associated with transmission electron microscopy were used for the localization in Tritrichomonas foetus of enzymes used as markers of different cell structures. Reaction product indicating the presence of Mg(2+)-adenosine triphosphatase (Mg(2+)-ATPase) and 5'-nucleotidase was observed in the plasma membrane. Glucose-6-phosphatase was seen in association with the endoplasmic reticulum, revealing its organization as parallel cisternae. Thiamino-pyrophosphatase was located in the cis-most region of the Golgi complex. Acid phosphatase was found within lysosomes as well as in several cisternae of the Golgi complex, in contrast to previous observations in mammalian cells. These observations provide support for the use of enzyme markers in future studies on cell fractionation of T. foetus.

Cytochemical localization of enzymes in the spermatid and the spermatozoon of Culex quinquefasciatus say (Diptera : Culicidae)

“…One of the features observed in the present study was the presence of the glucose-6-phosphatase reactivity in cisternae located in the transition zone between the endoplasmic reticulum and the Golgi complex. The present observations confirm a close topographical association of endoplasmic reticulum cisternae with the cisface of the Golgi complex in germinal cells (Sandoz, 1970;Hermo et al, 1980;ThorneTjomsland et al, 1991) and other cell types (Farquhar, 1985;Queiroz et al, 1991). The regions of the axoneme where acid phosphatase activity was detected coincide with known descriptions for the spermatozoa of a few insects Bigliardi et al, 1970;Baccetti, 1972;Baccetti et al, 1971Baccetti et al, , 1973bBeaulaton and PerrinWaldemer, 1973;Bao and Dolder, 1990;Bao, 1991).…”

Transient invagination of flagella by Tritrichomonas foetus

“…The size of internalized particles or structures does not necessarily determine which mechanism predominates, although in mammalian macrophages the contribution of phagocytosis generally increases with increasing particle size (Pratten and Lloyd 1986;Koval et al 1998). A very active endocytic machinery exists at the T. foetus cell surface (Benchimol et al 1981(Benchimol et al , 1986(Benchimol et al , 1990(Benchimol et al , 1992Queiroz et al 1991;Aonso et al 1994Aonso et al , 1997Granger and Warwood 1996;Tachezy et al 1996Tachezy et al , 1998, raising the possibility that the¯agella might be laterally internalized by a process akin to receptor-mediated endocytosis. Hypertonic medium inhibits clathrin-mediated endocytosis in mammalian cells by preventing clathrin from interacting with adaptor proteins (Daukas and Zigmond 1985;Hansen et al 1993); these conditions also inhibited¯a-gellar internalization by T. foetus.…”

“…Acid phosphatase activity was detected as previously described (Queiroz et al 1991) using either lead or cerium as the capture agent. For localization of surface-exposed carbohydrate residues the cells were incubated in the presence of gold-labeled Helix pomatia agglutinin (HPA) and wheat-germ agglutinin (WGA).…”

Cell fractionation of parasitic protozoa: a review

“…The fraction contained a population of small and large vesicles, some of which showed a multivesicular appearance. Enzyme assays showed an enrichment in the fraction of 5'-nucleotidase and Na + -K + -ATPase, two well characterized markers of the plasma membrane of eukaryotic cells and previously shown, using a cytochemical approach (Queiroz et al 1991), to be localized in the plasma membrane of T. foetus.…”