Chromosomal size conservation through the cell cycle supports karyotype stability in <i>Trypanosoma cruzi</i>

Galindo, Mario; Sabaj, Valeria; Espinoza, Ingrid; Toro, G. Cecilia; Búa, Jaqueline; Grenet, José; López‐Solís, Remigio; Ruiz, Andrés M.; Galanti, Norbel

doi:10.1016/j.febslet.2007.03.093

Cited by 4 publications

(2 citation statements)

References 28 publications

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“…Although the parasite's molecular karyotype seems to be relatively stable while it is maintained in the laboratory [25], chromosomal polymorphisms can be detected and probably emerge as a result of stressful conditions. This is of particular significance because T. cruzi does not undergo meiosis and the parasite generally reproduces asexually.…”

Section: Discussionmentioning

confidence: 99%

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

et al. 2013

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Trypanosoma cruzi comprises a pool of populations which are genetically diverse in terms of DNA content, growth and infectivity. Inter- and intra-strain karyotype heterogeneities have been reported, suggesting that chromosomal rearrangements occurred during the evolution of this parasite. Clone D11 is a single-cell-derived clone of the T. cruzi G strain selected by the minimal dilution method and by infecting Vero cells with metacyclic trypomastigotes. Here we report that the karyotype of clone D11 differs from that of the G strain in both number and size of chromosomal bands. Large chromosomal rearrangement was observed in the chromosomes carrying the tubulin loci. However, most of the chromosome length polymorphisms were of small amplitude, and the absence of one band in clone D11 in relation to its reference position in the G strain could be correlated to the presence of a novel band migrating above or below this position. Despite the presence of chromosomal polymorphism, large syntenic groups were conserved between the isolates. The appearance of new chromosomal bands in clone D11 could be explained by chromosome fusion followed by a chromosome break or interchromosomal exchange of large DNA segments. Our results also suggest that telomeric regions are involved in this process. The variant represented by clone D11 could have been induced by the stress of the cloning procedure or could, as has been suggested for Leishmania infantum, have emerged from a multiclonal, mosaic parasite population submitted to frequent DNA amplification/deletion events, leading to a 'mosaic' structure with different individuals having differently sized versions of the same chromosomes. If this is the case, the variant represented by clone D11 would be better adapted to survive the stress induced by cloning, which includes intracellular development in the mammalian cell. Karyotype polymorphism could be part of the T. cruzi arsenal for responding to environmental pressure.

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Section: Discussionmentioning

confidence: 99%

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

et al. 2013

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“…T . cruzi is a diploid organism [ 64 , 65 ] and according to genomic analysis and synteny maps the number of chromosomes varies across different strains [ 66 ], but is stable during the parasite cell cycle [ 67 ].…”

Section: Discussionmentioning

confidence: 99%

Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

et al. 2016

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Trypanosoma cruzi, the etiological agent of Chagas’ disease, presents three cellular forms (trypomastigotes, epimastigotes and amastigotes), all of which are submitted to oxidative species in its hosts. However, T. cruzi is able to resist oxidative stress suggesting a high efficiency of its DNA repair machinery.The Base Excision Repair (BER) pathway is one of the main DNA repair mechanisms in other eukaryotes and in T. cruzi as well. DNA glycosylases are enzymes involved in the recognition of oxidative DNA damage and in the removal of oxidized bases, constituting the first step of the BER pathway. Here, we describe the presence and activity of TcNTH1, a nuclear T. cruzi DNA glycosylase. Surprisingly, purified recombinant TcNTH1 does not remove the thymine glycol base, but catalyzes the cleavage of a probe showing an AP site. The same activity was found in epimastigote and trypomastigote homogenates suggesting that the BER pathway is not involved in thymine glycol DNA repair. TcNTH1 DNA-binding properties assayed in silico are in agreement with the absence of a thymine glycol removing function of that parasite enzyme. Over expression of TcNTH1 decrease parasite viability when transfected epimastigotes are submitted to a sustained production of H2O2.Therefore, TcNTH1 is the only known NTH1 orthologous unable to eliminate thymine glycol derivatives but that recognizes and cuts an AP site, most probably by a beta-elimination mechanism. We cannot discard that TcNTH1 presents DNA glycosylase activity on other DNA base lesions. Accordingly, a different DNA repair mechanism should be expected leading to eliminate thymine glycol from oxidized parasite DNA. Furthermore, TcNTH1 may play a role in the AP site recognition and processing.

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Nuclear Structure of Trypanosoma cruzi

Schenkman

Pascoalino

Nardelli

2011

Advances in Parasitology

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Chromosomal size conservation through the cell cycle supports karyotype stability in Trypanosoma cruzi

Cited by 4 publications

References 28 publications

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

Nuclear Structure of Trypanosoma cruzi

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