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Reservosome: an endocytic compartment in epimastigote forms of the protozoan <e1>Trypanosoma cruzi</e1> (Kinetoplastida: Trypanosomatidae). Correlation between endocytosis of nutrients and cell differentiation

Authors :
FIGUEIREDO, R. C. B. Q.
ROSA, D. S.
GOMES, Y. M.
NAKASAWA, M.
SOARES, M. J.
Source :
Parasitology; October 2004, Vol. 129 Issue: 4 p431-438, 8p
Publication Year :
2004

Abstract

Reservosomes are large membrane-bound organelles found at the posterior end of epimastigote forms of &lt;e1&gt;Trypanosoma cruzi&lt;/e1&gt;, but absent in amastigotes and trypomastigotes. We have transferred bloodstream trypomastigotes to LIT medium supplemented with gold-labelled transferrin in order to analyse, at the ultrastructural level, the occurrence of reservosomes and endocytosis during the trypomastigote to epimastigote differentiation. After 24 h, the trypomastigotes differentiated into amastigotes, which adhered to each other forming large clusters. Electron-dense vesicles were detected close to the Golgi complex in cells with intermediary characteristics between amastigotes and epimastigotes, but typical reservosomes at the posterior cell tip were still absent. Transferrin–gold complexes were observed only bound to the surface of clustered cells. After 72 h, epimastigotes were observed being released from the clusters and free-swimming epimastigotes appeared, containing electron-dense vesicles at their posterior region. Typical reservosomes, labelled with transferrin–gold, were observed only in free-swimming epimastigotes. When fully differentiated epimastigotes were incubated with transferrin–gold complexes and then processed for the immunocytochemical detection of cysteine proteinase, all reservosomes were positive for the enzyme, but co-localization of both markers did not occur in all organelles. Our data demonstrate that in &lt;e1&gt;T. cruzi&lt;/e1&gt; epimastigotes endocytosis is strongly related to reservosome biogenesis during the trypomastigote to epimastigote differentiation process.

Details

Language :
English
ISSN :
00311820 and 14698161
Volume :
129
Issue :
4
Database :
Supplemental Index
Journal :
Parasitology
Publication Type :
Periodical
Accession number :
ejs6408165