Transcriptome analysis upon TFIIS4 silencing during autogamy time course

At each sexual cycle, during development of the somatic macronucleus (MAC) from the germline micronucleus (MIC), the genome of the ciliate Paramecium tetraurelia is massively rearranged through the reproducible elimination of germline-specific sequences. It has been reported previously that targeting of these sequences is mediated by non-protein-coding RNAs including different classes of small RNAs and longer non-coding transcripts. Using RNA interference, we showed that TFIIS4 gene encoding development-specific TFIIS elongation factor is essential for the formation of a functional somatic genome. We demonstrated that genome rearrangements taking place during MAC development were inhibited in TFIIS4-depleted cells, which led to high lethality in the sexual progeny. The role of TFIIS4 elongation factor in coding transcription at the genome-wide level was studied by performing a microarray hybridization experiment using RNA samples extracted during vegetative growth and at five time points during the progression of the sexual cycle (autogamy). Total RNA samples were extracted during vegetative growth and at five different time points of autogamy from mass cultures fed with bacteria producing dsRNA to induce TFIIS4 or ICL7a silencing. TFIIS4 gene encodes TFIIS elongation factor and is strongly induced during autogamy, a self-fertilization process. RNAi against TFIIS4 leads to strong lethality in post-autogamous progeny. ICL7a is a non-essential gene; the loss of function of this gene by with dsRNA feeding results in mutant phenotypes: absence of intraciliary lattice and defect in calcium-induced cell contractility.