Elucidation of the Aspergillus fumigatus tRNA-derived RNA repertoire from conidia and mycelium

Abstract

Aspergillus fumigatus is a ubiquitous filamentous fungus that causes devastating infections in severely immunocompromised individuals in the clinic. Pathogenesis relies in part on a combination of fine-tuned stress response pathways and rapid growth rate. Previous literature suggests that A. fumigatus produces a finite pool of small RNAs, consisting in part of tRNA-derived RNAs (tDRs). Here, we improve our understanding of the tDRs of A. fumigatus produced in conidia and mycelium using small RNA-sequencing and a cutting-edge tDR-sequencing approach. We find tDRs to be differentially abundant across fungal morphotypes, with specific fragments proving dominant in particular morphotypes (e.g., Asp(GTC)-5’tRH in conidia; His(GTG)-5’tRH in mycelium). Consistent with the literature, we observed distinct patterns of tDRs from nuclear- and mitochondria-derived tDRs and found tDR-seq to provide a modestly improved view of the tDRs of A. fumigatus over standard sRNA-seq. Ultimately, we have provided an improved description of the sRNA landscape of A. fumigatus and uncovered numerous small RNA species likely linked to gene regulation in this important human pathogen.