Introgression of the Kinetoplast DNA: An Unusual Evolutionary Journey in Trypanosoma cruzi

Introduction: Phylogenetic relationships between different lineages of Trypanosoma cruzi, the agent of Chagas disease, have been controversial for several years. However, recent phylogenetic and phylogenomic analyses clarified the nuclear relationships among such lineages. However, incongruence between nuclear and kinetoplast DNA phylogenies has emerged as a new challenge. This incongruence implies several events of mitochondrial introgression at evolutionary level. However, the mechanism that gave origin to introgressed lineages is unknown. Here, I will review and discuss how maxicircles of the kinetoplast were horizontally and vertically transferred between different lineages of T. cruzi. Conclusion: Finally, I will discuss what we know - and what we don't - about the kDNA transference and inheritance in the context of sexual reproduction in this parasite.