title: Subtelomeric I-SceI-Mediated Double-Strand Breaks Are Repaired by Homologous Recombination inTrypanosoma cruzi.
abstract: Trypanosoma cruzichromosome ends are enriched in surface protein genes and pseudogenes (e.g., trans-sialidases) surrounded by repetitive sequences. It has been proposed that the extensive sequence variability among members of these protein families could play a role in parasite infectivity and evasion of host immune response. In previous reports we showed evidence suggesting that sequences located in these regions are subjected to recombination. To support this hypothesis we introduced a double-strand break (DSB) at a specific target site in aT. cruzisubtelomeric region cloned into an artificial chromosome (pTAC). This construct was used to transfectT. cruziepimastigotes expressing the I-SceI meganuclease. Examination of the repaired sequences showed that DNA repair occurred only through homologous recombination (HR) with endogenous subtelomeric sequences. Our findings suggest that DSBs in subtelomeric repetitive sequences followed by HR between them may contribute to increased variability inT. cruzimultigene families.
authors.affiliation: Laboratorio de Genética Molecular "Dr. Yunis-Turbay," Decanato de Ciencias de la Salud, Universidad Centroccidental Lisandro Alvarado Barquisimeto, Venezuela.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Chiurillo
authors.affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville MD, USA.
authors.forename: Roberto R
authors.initials: RR
authors.lastname: Moraes Barros
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, Brazil.
authors.forename: Renata T
authors.initials: RT
authors.lastname: Souza
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, Brazil.
authors.forename: Marjorie M
authors.initials: MM
authors.lastname: Marini
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, Brazil.
authors.forename: Cristiane R
authors.initials: CR
authors.lastname: Antonio
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, Brazil.
authors.forename: Danielle R
authors.initials: DR
authors.lastname: Cortez
authors.affiliation: Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular - Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires, Argentina.
authors.forename: María Á
authors.initials: MÁ
authors.lastname: Curto
authors.affiliation: Department of Infectious Diseases, J. Craig Venter Institute, Rockville MD, USA.
authors.forename: Hernán A
authors.initials: HA
authors.lastname: Lorenzi
authors.affiliation: Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular - Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires, Argentina.
authors.forename: Alejandro G
authors.initials: AG
authors.lastname: Schijman
authors.affiliation: Centro de Biotecnología, Fundación Instituto de Estudios Avanzados Caracas, Venezuela.
authors.forename: José L
authors.initials: JL
authors.lastname: Ramirez
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, Brazil.
authors.forename: José F
authors.initials: JF
authors.lastname: da Silveira
keywords: DNA repair; I-SceI meganuclease; T. cruzi; artificial chromosomes; double-strand break; homologous recombination; telomere