Life stage specific poly(A) site selection regulated by Trypanosoma brucei DRBD18

In this work, we examine the function of DRBD18 in T. brucei, here using single cell RNA sequencing (scRNAseq) of uninduced and induced DRBD18 knockdowns. In insect procyclic form, we identified one major and one minor population of cells that dramatically increased upon DRBD18 knockdown. Both of these cell populations were significantly enriched for transcripts that are normally upregulated in the quiescent stumpy bloodstream form and metacyclic (MF) life cycle stages, consistent with a role for DRBD18 in life cycle progression. Furthermore, the 3’ end bias of our sequencing technique allowed us to investigate the effect of DRBD18 on poly(A) site selection, and extension of gene annotations permitted a comprehensive analysis of these changes. We found that 3’UTR shortening upon DRBD18 depletion was prevalent, with over 1500 transcripts exhibiting this this phenotype, and RIPseq analyses showed significant overlap between bound transcripts and those with 3’UTR shortening 10x genomics single cell RNA sequencing (scRNAseq) of uninduced and induced DRBD18 knockdowns