PRJNA270821
small RNA sequencing from Paramecium tetraurelia cells deficient in the dsRNA-inducible RNA interference pathway.
In the ciliate Paramecium tetraurelia, an efficient RNAi response can be triggered by feeding cells with bacteria producing double-stranded RNA against an endogenous gene. Some of the genes involved also control the production of endogenous siRNAs, but the natural functions of these interconnected pathways are unknown. In this study, we provide the first deep-sequencing data of small RNAs produced in vegetatively growing wild-type and RNAi-mutant Paramecium strains. Cells were subjected to dsRNA feeding with the aims (i) to test the previous hypothesis that a transitivity mechanism produces secondary siRNAs, (ii) to shed light on the mechanisms of primary and secondary siRNA synthesis by dissecting their genetic requirements, and (iii) to provide new insight into the natural functions of these pathways. These data demonstrate that the production of secondary siRNAs from the target mRNA, transitive to their previous trigger, is a component of RNAi in ciliates, but that the mechanism differs from the previously described ones in nematodes and plants. Moreover, the study shows that essential and non-essential factors of the dsRNA-inducible RNAi pathway are required to accumulate endogenous siRNAs.