Navegando por Palavras-chave "nucleus"

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    Chromatin and nuclear organization in Trypanosoma cruzi
    (Future Medicine Ltd, 2009-10-01) Elias, Maria Carolina; Nardelli, Sheila Cristina [UNIFESP]; Schenkman, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Inst Butantan
    A total of 100 years have passed since the discovery of the protozoan Trypanosoma cruzi, the etiologic agent of Chagas' disease. Since its discovery, the molecular and cellular biology of this early divergent eukaryote, as well as its interactions with the mammalian and insect hosts, has progressed substantially. It is now clear that this parasite presents unique mechanisms controlling gene expression, DNA replication, cell cycle and differentiation, generating several morphological forms that are adopted to survive in different hosts, in recent years, the relationship between the chromatin structure and nuclear organization with the unusual transcription, splicing, DNA replication and DNA repair mechanisms have been investigated in T. cruzi. This article reviews the relevant aspects of these mechanisms in relation to chromatin and nuclear organization.
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    Morphological events during the Trypanosoma cruzi cell cycle
    (Elsevier B.V., 2007-04-01) Elias, Maria Carolina; Cunha, Julia P. C. da; Faria, Flavio P. de; Mortara, Renato A.; Freymueller, Edna; Schenkman, Sergio; Universidade Federal de São Paulo (UNIFESP); Inst Butantan
    The replication and segregation of organelles producing two identical daughter cells must be precisely controlled during the cell cycle progression of eukaryotes. in kinetoplastid flagellated protozoa, this includes the duplication of the single mitochondrion containing a network of DNA, known as the kinetoplast, and a flagellum that grows from a cytoplasmic basal body through the flagellar pocket compartment before emerging from the cell. Here, we show the morphological events and the timing of these events during the cell cycle of the epimastigote form of Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease. DNA staining, flagellum labeling, bromodeoxyuridine incorporation, and ultra-thin serial sections show that nuclear replication takes 10% of the whole cell cycle time. in the middle of the G2 stage, the new flagellum emerges from the flagellar pocket and grows unattached to the cell body. While the new flagellum is still short, the kinetoplast segregates and mitosis occurs. the new flagellum reaches its final size during cytokinesis when a new cell body is formed. These precisely coordinated cell cycle events conserve the epimastigote morphology with a single nucleus, a single kinetoplast, and a single flagellum status of the interphasic cell. (C) 2006 Elsevier GmbH. All rights reserved.