Pseudouridine RNA modification on small non-coding RNAs in Trypanosoma brucei : identification of novel sites and functional implications

Y-seq and HydraPsiSeq are the two genome-wide approaches available for mapping pseudouridine on RNAs. Trypanosoma brucei is the causative agent of sleeping sickness that cycles between an insect and a mammalian host. Here, three mapping approaches were applied for mapping Ys on T. brucei small nucleolar RNA (snoRNA), 7SL RNA, Vault RNA and tRNAs. Ys mapped on C/D snoRNA guiding 2-O-methylation were shown to increase the efficiency of guiding the modification on its target. Differential level of Ys on these ncRNAs were found in the two life stages of the parasite. tRNA isoform abundance were identified in the two life stages and is correlated with stage specific mRNA expression. The data supports the contribution of Y to regulating gene expression during cycling of the parasite between its two hosts.