Strain-specific genome evolution in Trypanosoma cruzi, the agent of Chagas disease

• DOI: 10.1371/journal.ppat.1009254
• Publication Date: 2021-01-28T19:45:59Z
• Authors: Wei Wang; Duo Peng; Rodrigo P. Baptista; Yiran Li; Jessica C. Kissinger; Rick L. Tarleton
• Keywords: Chagas Disease; Antigenic variation

The protozoan Trypanosoma cruzi almost invariably establishes life-long infections in humans and other mammals, despite the development of potent host immune responses that constrain parasite numbers. consistent, decades-long persistence T . human hosts arises at least part from remarkable level genetic diversity multiple families genes encoding primary target antigens anti-parasite responses. However, highly repetitive nature genome–largely a result these same extensive genes–have prevented full understanding extent gene its maintenance In this study, we have combined long-read sequencing proximity ligation mapping to generate very high-quality assemblies two strains representing apparent ancestral lineages species. These reveal not only repertoire members large strains, demonstrating extreme within between isolates, but also provide evidence processes maintain diversity, including amplification, dispersion copies throughout genome diversification via recombination situ mutations. Gene amplification events yield significant copy number variations substantial presumably required for or involved evasion, thus forming second strain-dependent variation flexibility evident appears create unique challenges with respect preserving core functions expression sets species apart related kinetoplastids.