Dual roles for piRNAs in promoting and preventing transgenerational gene silencing in C. elegans

To explore the roles of piRNAs in regulating 22G-RNA production and transgenerational gene silencing, we used RNA-seq to assess changes in small RNA and mRNA levels in piwi/prg-1 and mutator mutants at an early generation and again at a late generation. We identified that in the absence of piRNAs, many genes gain 22G-RNAs which in turn guide transgenerational gene silencing. Small RNA and mRNA high-throughput sequencing was done using RNA isolated from adult wild type and prg-1 and mutator mutant whole animals. Differential expression analysis was done to identify changes in gene expression in mutants relative to wild type animals.