Identification of novel interspersed DNA repetitive elements in the trypanosoma cruzi genome associated with the 30UTRs of surface multigenic families

Abstract

Trypanosoma cruzi is the etiological agent of Chagas disease, which affects millions ofpeople in Latin America. No transcriptional control of gene expression has been demonstrated inthis organism, and 50% of its genome consists of repetitive elements and members of multigenic families. In this study, we applied a novel bioinformatics approach to predict new repetitive elementsin the genome sequence of T. cruzi. A new repetitive sequence measuring 241 nt was identified and found to be interspersed along the genome sequence from strains of different DTUs. This new repeatwas mostly on intergenic regions, and upstream and downstream regions of the 241 nt repeat were enriched in surface protein genes. RNAseq analysis revealed that the repeat was part of processedmRNAs and was predominantly found in the 30 untranslated regions (UTRs) of genes of multigenic families encoding surface proteins. Moreover, we detected a correlation between the presence ofthe repeat in the 30UTR of multigenic family genes and the level of differential expression of thesegenes when comparing epimastigote and trypomastigote transcriptomes. These data suggest that thissequence plays a role in the posttranscriptional regulation of the expression of multigenic families.