Lack of evidence for integration of Trypanosoma cruzi minicircle DNA in South American human genomes

Horizontal gene transfer involving kinetoplast DNA minicircles between Trypanosoma cruzi and its mammalian hosts has recently been proposed as a usual consequence of infection ( Hecht et al., 2010). However, we have found no sequences longer than 29 bp perfectly matching minicircles of T. cruzi in the unassembled reads from Colombian and Peruvian human populations provided by the 1,000 Genome project (129 individuals in total, coverage from 1.4× to 36.3×, read length from 42 to 101 bp). The weak sequence matches that were identified are shared with a Finnish population used as a control from a non-endemic area.

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► Genomic reads of three human populations were screened for Trypanosoma cruzi minicircle sequences.
► No perfect matches longer than 29 bp were detected in 129 individuals.
► Presence of similar matches in South Americans and Europeans suggests they are accidental.
► Heritable integration of kDNA minicircles into the human genome is probably not a usual consequence of Chagas disease.