Single molecule analysis of Trypanosoma brucei DNA replication dynamics.
Nucleic Acids Res
; 43(5): 2655-65, 2015 Mar 11.
Article
en En
| MEDLINE
| ID: mdl-25690894
ABSTRACT
Eukaryotic genome duplication relies on origins of replication, distributed over multiple chromosomes, to initiate DNA replication. A recent genome-wide analysis of Trypanosoma brucei, the etiological agent of sleeping sickness, localized its replication origins to the boundaries of multigenic transcription units. To better understand genomic replication in this organism, we examined replication by single molecule analysis of replicated DNA. We determined the average speed of replication forks of procyclic and bloodstream form cells and we found that T. brucei DNA replication rate is similar to rates seen in other eukaryotes. We also analyzed the replication dynamics of a central region of chromosome 1 in procyclic forms. We present evidence for replication terminating within the central part of the chromosome and thus emanating from both sides, suggesting a previously unmapped origin toward the 5' extremity of chromosome 1. Also, termination is not at a fixed location in chromosome 1, but is rather variable. Importantly, we found a replication origin located near an ORC1/CDC6 binding site that is detected after replicative stress induced by hydroxyurea treatment, suggesting it may be a dormant origin activated in response to replicative stress. Collectively, our findings support the existence of more replication origins in T. brucei than previously appreciated.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Trypanosoma brucei brucei
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ADN Protozoario
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Origen de Réplica
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Replicación del ADN
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Biología Molecular
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2015
Tipo del documento:
Article
País de afiliación:
Brasil