title: Lysosome-like compartments of Trypanosoma cruzi trypomastigotes may originate directly from epimastigote reservosomes.
abstract: Trypanosoma cruzi epimastigote reservosomes store nutrients taken up during the intense endocytic activity exhibited by this developmental form. Reservosomes were classified as pre-lysosomal compartments. In contrast, trypomastigote forms are not able to take up nutrients from the medium. Interestingly, trypomastigotes also have acidic organelles with the same proteases contained in epimastigote reservosomes. Nevertheless, the origin and function of these organelles have not been disclosed so far. Given the similarities between the compartments of epimastigotes and trypomastigotes, the present study aimed to investigate the origin of metacyclic trypomastigote protease-containing organelles by tracking fluorospheres or colloidal gold particles previously stored in epimastigotes' reservosomes throughout metacyclogenesis. Using three-dimensional reconstruction of serial electron microscopy images, it was possible to find trypomastigote compartments containing the tracer. Our observations demonstrate that the protease-containing compartments from metacyclic trypomastigotes may originate directly from the reservosomes of epimastigotes.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: Juliana C
authors.initials: JC
authors.lastname: Vidal
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: Carolina DE L
authors.initials: CL
authors.lastname: Alcantara
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: Wanderley
authors.initials: W
authors.lastname: DE Souza
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro,Rio de Janeiro,Brazil.
authors.forename: Narcisa L
authors.initials: NL
authors.lastname: Cunha-E-Silva
mesh_terms: D000704:Analysis of Variance; D004705:Endocytosis / Q000502:physiology; D005434:Flow Cytometry; D006046:Gold / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D021621:Imaging, Three-Dimensional; D008018:Life Cycle Stages; D008247:Lysosomes / Q000378:metabolism* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D014349:Trypanosoma cruzi / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D049452:Green Fluorescent Proteins; D006046:Gold
keywords: 
                 Trypanosoma cruzi
              ; lysosome-like organelles; metacyclogenesis; reservosomes; trypomastigotes