Endosymbiosis in protozoa of the Trypanosomatidae family

Abstract

A small number of trypanosomatids present bacterium endosymbionts in the cytoplasm, which divide synchronously with the host cell. Crithidia oncopleti, Crithidia deanei. Crithidia desouzai, Blastocrithidia culicis and Herpetomonas roitmani are the best characterized species. The endosymbiont is surrounded by two membranes separated from each other by an electron-lucent space. The presence of the endosymbiont led to the appearance of morphological changes which include the lack of the paraflagellar rod associated to the axoneme, the morphology of the kinetoplast and the association of the sub-pellicular microtubules with portions of the protozoan plasma membrane. Aposymbiotic strains could be obtained by antibiotic treatment, opening the possibility to make comparative analysis of endosymbiont-containing an endosymbiont-free populations of the same species. It is clear that metabolic cycles are established between the prokaryiont and the host cell. The results obtained show that endosymbiont-containing species of trypanosomatids constitute an excellent model to study basic processes on the endosymbiont-host cell relationship and the origin of new organelles.

Development of a toolbox to dissect host-endosymbiont interactions and protein trafficking in the trypanosomatid Angomonas deanei

“…5b). In contrast, cells transfected with the pAEX-EGFP-SKL cassette showed the characteristic punctate pattern of fluorescence in accord with localization of the EGFP to trypanosomatid glycosomes [36, 37], while cells transfected with the pAEX-mito-EGFP cassette showed a tubule-like fluorescence pattern that reflects the unique shape of the A. deanei mitochondrion [38] (Fig. 5b).…”

Biological Roles of Peptidases in Trypanosomatids~!2009-11-26~!2010-02-15~!2010-03-18~!

“…It is well known that the symbiont interferes with several aspects of the host trypanosomatid physiology [233], including the production of proteolytic enzymes [10,23,26]. In this sense, previous studies showed that endosymbiont-bearing strains are more efficient in binding to insect cell lines and midguts, as compared to symbiotic free strains, which is probably related to differential expression of surface molecules [27,234].…”

The surface charge of trypanosomatids

“…Crithidia deanei belongs to a restrict group of trypanosomatids presenting bacterium endosymbionts in the cytoplasm, which divide synchronously with the host cell (De Souza and Motta 1999). This group also includes C. oncopleti (Newton and Horne 1957), C. desouzai (Fiorini et al 1989), Blast- Pimenta and De Souza 1983, Saraiva et al 1989, Silva Filho et al 1990.…”

“…The possibility of elimination of the endosymbiont by the use of antibiotics has increased the interest in the study of endosymbiont-harboring species. The available data indicate that the presence of the endosymbiont induces morphological changes, as the lack of paraflagellar structure located in the flagellum (Freymüller and Camargo 1981) interferes with the metabolism of the trypanosomatid (Newton 1957, Mundim et al 1974, Alfieri and Camargo 1982, Salzman et al 1985, De Souza and Motta 1999, diminishes the secretion of proteolytic enzymes (d'Avila-Levy et al 2001), interferes with surface properties of the protozoan such as exposition of carbohydrate residues (Dwyer and Chang 1976, Esteves et al 1982, McLaughlin and Cain 1985, Faria e Silva et al 1994) and on the surface charge (Oda et al 1984). Symbiont-free C. deanei presents a mean EPM of −0.99µm.s −1 .V −1 .cm, which is 15% more negative than the symbiont-free strain.…”