Interest and limitations of Spliced Leader Intergenic Region sequences for analyzing Trypanosoma cruzi I phylogenetic diversity in the Argentinean Chaco

NICOLÁS TOMASINI; JUAN JOSÉ LAUTHIER; MARÍA M. MONJE RUMI; PAULA G. RAGONE; ANAHÍ M. ALBERTI DAMATO; CECILIA PÉREZ BRANDAN; CAROLINA I. CURA; ALEJANDRO G. SCHIJMAN; CHRISTIAN BARNABÉ; MICHEL TIBAYRENC; MIGUEL A. BASOMBRÍO; ALEJANDRA FALLA; CLAUDIA HERRERA; FELIPE GUHL; PATRICIO DIOSQUE

Infection, Genetics and Evolution

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011 vol. 11 p. 300 - 307

1567-1348

Internal and geographical clustering within Trypanosoma cruzi I (TcI) has been recently revealed by using Multilocus Microsatellite Typing and sequencing of the Spliced-Leader Intergenic Region (SL-IR). In the present work, 14 isolates and 11 laboratory-cloned stocks obtained from a geographically restricted area in Chaco Province, Argentina, were analyzed by PCR and sequencing of SL-IR. We were able to differentiate 8 different genotypes that clustered into 4 groups. One of these groups was classified within the formerly described haplotype A and another one within the recently described SL-IR group E. Both were phylogenetically well-supported. In contrast, none of the stocks from the Chaco province were grouped within the cluster previously named haplotype D despite the fact that they shared a similar microsatellite motif in the SL-IR. No evidence of recombination or gene conversion within these stocks was found. On the other hand, multiple ambiguous alignments in the microsatellite region of SL-IR, affecting the tree topology and relationships among groups were detected. Finally, since there are multiple copies of the SL-IR, and they are arranged in tandem, we discuss how molecular processes affecting this kind of sequences could mislead phylogenetic inference.