9Eukaryotic cells, including fungi, release extracellular vesicles (EVs). These lipid 2 0 bilayered compartments play essential roles in cellular communication and pathogenesis.
1EV composition is complex and includes proteins, glycans, pigments, and RNA. RNA 2 2 classes with putative roles in pathogenesis have been described in EVs produced by 2 3 fungi. Here we describe the RNA content in EVs produced by the G186AR and G217B 2 4 strains of Histoplasma capsulatum, an important human fungal pathogen. A total of 124 2 5 mRNA were identified in both strains. In this set of RNA classes, 93 transcripts were 2 6 enriched in EVs from the G217B strain, while 31 enriched in EVs produced by the G186AR 2 7 strain. This result suggests that there are important strain-specific properties in the mRNA 2 8 composition of fungal EVs. We also identified short fragments (25-40 long) that were 2 9 strain-specific, with a greater number of them identified in EVs produced by the G217B 3 0 strain. Remarkably, the most enriched processes were stress responses and translation.
1Half of these fragments aligned to the reverse strand of the transcript, suggesting the 3 2 occurrence of miRNA-like molecules in fungal EVs. We also compared the transcriptome 3 3 profiles of H. capsulatum with the RNA composition of EVs and no correlation was 3 4observed. Altogether, our study provided information about the RNA molecules present in 3 5 H. capsulatum EVs, and the differences in composition between the G186AR and G217B 3 6 strains. In addition, we showed that the correlation between the most expressed 3 7 transcripts in the cell and their presence in the EVs, reinforcing the idea that the RNAs 3 8were directed to the EVs by a regulated mechanism.