Total RNA was extracted from Tetrahymena cells using the RNeasy Protect Cell minikit (Qiagen), as described (TetraFGD, http://tfgd.ihb.ac.cn/index/smphelp). Polyadenylated transcripts were enriched using Sera-Mag magnetic oligo-dT beads (GE). First strand-specific libraries were constructed using the Illumina TruSeq Stranded mRNA sample preparation kit (RS-122-2101). Small RNA was enriched by a mirVana™ miRNA isolation kit (Ambion). Small RNA libraries were constructed using the Illumina TruSeq Small RNA Sample Prep kit (RS-200-0012). Sequencing was performed using an Illumina HiSeq-2500 sequencer. Analysis of polyadenylated transcripts was performed as described previously (Xiong et al. 2012 (link); Feng et al. 2017 (link)). Analysis of small RNA was performed as described (Schoeberl et al. 2012 (link)).