Two main clusters within Trypanosoma cruzi zymodeme 3 are defined by distinct regions of the ribosomal RNA cistron

Abstract

Trypanosoma cruzi is currently classified into 2 major phylogenetic lineages, T. cruzi I and II, that correlate with the formerly described zymodeme 1 and 2, respectively. Another isoenzymic group (zymodeme 3-Z3) was also described. In this study, we analysed the genetic diversity among Z3 isolates of the Brazilian Amazon by restriction fragment length polymorphism of the intergenic transcribed spacers (ITSs) of the ribosomal RNA cistron and the size of the divergent domain D7 of the 24Salpha rRNA gene. DNAs from 12 T. cruzi Z3 isolates obtained from humans (2), Panstrongylus geniculatus (1), and Rhodnius brethesi (9) were submitted to PCR amplification of the ITSs plus the 5.8S rDNA. The PCR products were digested with 4 distinct endonucleases and the profiles analysed by a numerical methodology. The phenetic dendrogram revealed a clear dichotomy in the Z3 group, defining 2 groups that were named Z3-A and Z3-B. Dimorphism was also found in the band sizes of the amplified D7 divergent domain of the 24Salpha rDNA, which showed a perfect correlation with the ITSs clustering. The organization of the ribosomal cistron was investigated by Southern blotting and shown to be conserved in the genome of the 2 Z3 groups. This study shows that the rDNA cistron allows the definition of 2 distinct subclusters in Z3 isolates.

Coexistence of Trypanosoma cruzi Genotypes in Wild and Periodomestic Mammals in Chile

“…Genotype TCII includes five sub-genotypes: TCIIa (clonets 27-29), TCIIb (clonets 30-34), TCIIc (clonets [35][36][37], TCIId (clonets 38-39), and TCIIe (clonets 40-43), [19][20][21][22][23] Genotype TCIIb corresponds to Z2 17 and genotypes TCIIa and TCIIc correspond to Z3. 24 It has been proposed that the fusion between genotypes TCI and TCIIb generated the heterozygous hybrids TCIIa and TCIIc, and fusion between genotypes TCIIb and TCIIc generated the hybrids TCIId and TCIIe. 25,26 In this study, we report T. cruzi genotypes circulating in four wild and one peridomestic mammal hosts from central Chile.…”

Two Hybridization Events Define the Population Structure of Trypanosoma cruzi

“…Understanding the relationship of DTUs IIa and IIc (Zymodeme III) to other DTUs has been complicated by experimental results yielding contrary associations: MLEE and RAPD assays and HSP60 gene sequences show an overall similarity to DTU IIb (Tibayrenc 1995;Sturm et al 2003), while individual enzyme profiles and SL RNA and rRNA gene sequences indicate similarity to DTU I (Miles et al 1978;Coura et al 2002;Mendonc xa et al 2002).…”

Genes de cisteíno proteases (Catepsina L-like) de Trypanosoma rangeli: polimorfismo, relações filogenéticas e alvos para diagnóstico e genotipagem.

“…Análises de sítios de restrição do ITS rDNA amplificado por PCR revelaram variabilidade inter e intra-específica em T. cruzi (MENDONÇA et al, 2002), T. rangeli (MAIA DA SILVA et al, 2004b;BELTRAME-BOTELHO et al, 2005) e outras espécies de tripanossomas (DESQUENES et al, 2001;RODRIGUES et al, 2006;CORTEZ et al, 2006). A utilização de seqüências de ITS rDNA para inferências filogenéticas revelou que os isolados de T. rangeli podem ser distribuídos em 5 linhagens (MAIA DA SILVA et al, 2004b;2009 In Press).…”