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

RUSMAN FANNY; TOMASINI NICOLÁS; FLORIDIA YAPUR NOELIA; RAGONE PAULA GABRIELA; ACUÑA LEONARDO; DIOSQUE PATRICIO

Salta

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

The kinetoplastic (mitochondrial) DNA of Trypanosoma cruzi consists in two types of molecules: maxicircles and minicircles. Maxicirclesencode typical mitochondrial products (rRNA and respiratory chain subunits), although some of the protein coding genes are encrypted. Togenerate functional mRNAs, it is required an intricate process of RNA editing that involves the insertion and elimination of uridine residues atspecific messenger sites. Genetic information for editing is provided by guide RNAs (gRNAs) encoded by minicircles. Unfortunately, mRNAedition and gRNA repertoires are mostly unknown in T.cruzi. In the present work, we have inferred gRNAs on deep-sequenced minicirclehypervariable regions (mHVRs) and rebuilt edition cascades for nine T. cruzi strains belonging to the six main lineages (TcI-TcVI). A total of6,743,029 gRNAs were detected. Inferred gRNAs were clustered according to sequence similarity to constitute gRNA classes. Results showedan extreme diversity of gRNA classes, highly frequent minicircles that apparently do not code gRNAs and very divergent gRNA repertoiresamong lineages and within some lineages. In addition, we observed variable gRNA class redundancy (different gRNA classes that edits the samemRNA region) among strains. It was also observed that some strains have upon four times more gRNA classes than others. In addition, we failedto rebuild complete cascades for components of the respiratory complex I in several strains. Finally, we observed that gRNA classes fromdifferent strains may potentially edit mRNAs from other lineages in the same way as they edit their self mRNAs. This is a requisite forsuitability of biparental inheritance of minicircles in hybrids, a recently proposed hypothesis in T. cruzi. Different evolutionary mechanisms andbiological process are discussed in order to explain differences among strains and lineages.