DEEP DESCRIPTION OF MITOCHONDRIAL GUIDE RNA REPERTOIRES IN THE SIX MAIN LINEAGES OF TRYPANOSOMA CRUZI

FANNY RUSMAN; NICOLÁS TOMASINI; NOELIA FLORIDIA-YAPUR; PAULA G. RAGONE; LEONARDO ACUÑA; PATRICIO DIOSQUE

Salta

Congreso; The LV Annual SAIB Meeting and XIV PABMB Congress; 2019

Sociedad Argentina de Bioquímica y Biología Molecular

The kinetoplast (mitochondrial) DNA of Trypanosoma cruzi consists of two types of molecules: maxicircles and minicircles. Maxicircles encodetypical mitochondrial products (rRNA and respiratory chain subunits), although some of the protein-coding genes are encrypted. To generatefunctional mRNAs, it is required an intricate process of RNA editing that involves the insertion and elimination of uridine residues at specificmessenger sites. Genetic information for editing is provided by guide RNAs (gRNAs) encoded by minicircles. Unfortunately, mRNA edition andgRNA repertoires are mostly unknown in T. cruzi. In the present work, we have inferred gRNAs on deep-sequenced minicircle hypervariableregions (mHVRs) and rebuilt edition cascades for nine T. cruzi strains belonging to the six main lineages (TcI-TcVI). A total of 6743029 gRNAswere detected. Inferred gRNAs were clustered according to sequence similarity to constitute gRNA classes. Results showed an extreme diversityof gRNA classes, highly frequent minicircles that presumably do not code gRNAs, and very divergent gRNA repertoires, among lineages andwithin some lineages. In addition, we observed variable gRNA class redundancy (different gRNA classes that edit the same mRNA region) amongstrains. It was also observed that some strains have upon four times more gRNA classes than the others. In addition, we failed to rebuild completecascades for components of the respiratory complex I in several strains. Finally, we observed that gRNA classes from different strains maypotentially edit mRNAs from other lineages in the same way as they edit their self mRNAs. This is a requisite for the suitability of biparentalinheritance of minicircles in hybrids, a recently proposed hypothesis in T. cruzi. Different evolutionary mechanisms and biological processes arediscussed in order to explain differences among strains and lineages.