Trypanosoma cruzi: An analysis of the minicircle hypervariable regions diversity and its influence on strain typing

• Autores: Velázquez, Melisa María del Luján; Diez, Cristina Noemí; Mora, C.; Diosque, Patricio; Marcipar, Iván Sergio
• Año de publicación: 2008
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Deoxynucleotide Triphosphate; Dntp; Kdna; Kinetoplastid Dideoxy Nucleotide Acid; Lineage; Low Stringency Single Specific Primer Polymerase Chain Reaction; Lssp-Pcr; Mhvr; Minicircle; Minicircle Hypervariable Regions; Pcr; Polimerase Chain Reaction; Randomly Amplified Polymorphic Dna; Rapd; Restriction Fragment Length Polymorphism; Rflp; Strain; Trypanosoma Cruzi; Typing
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The current intraspecific nomenclature in Trypanosoma cruzi describes two major lineages, named T. cruzi I and T. cruzi II, and five sublineages within T. cruzi II, named IIa, IIb, IIc, IId and IIe. The polymorphism of minicircle hypervariable regions (mHVRs) of T. cruzi has been used in many studies for the molecular characterization of parasite populations directly from biological samples. However, the molecular bases that allow strain typing by these markers are still unclear. In this work we examined forty cloned mHVRs sequences of CL-Brener reference strain (IIe sublineage), and we found a predominant group of sequences, with 40% of frequency in this strain, with a 97% of identity among them. Out of the forty clones analyzed, we identified other less representative types, and a few unique ones. This predominant sequence is also present in different reference strains belonging to the other main T. cruzi lineages and sublineages (TcI, IIa, IIb, IIc and IId) although in a many thousand times lower frequency than in the CL-Brener strain, as shown by semiquantitative PCR. Similarly, predominant mHVR sequences previously described for TcIId strains, were clearly more frequent (many thousand times higher) in the IId reference strain analyzed by us (Mncl2) than within the reference strains belonging to the other lineages and sublineages. The analysis of the cloned sequences shows that more sequences than just the major one contribute to define the global pattern of mHVRs RFLP in the CL-Brener strain. The possible usefulness of these predominant sequences for typing TcIId and TcIIe sublineages by semiquantitative PCR, as well as the possible role of these sequences in genotype identification by mHVR probes are discussed.
Fil: Velázquez, Melisa María del Luján. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; Argentina
Fil: Diez, Cristina Noemí. Universidad Nacional del Litoral; Argentina
Fil: Mora, C.. Universidad Nacional del Litoral; Argentina
Fil: Diosque, Patricio. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentina
Fil: Marcipar, Iván Sergio. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina