piRNAs induce transcriptional silencing and heterochromatinizationin the progeny.

heterochromatinization-500Piwi targets transposon sequences for chromatin-mediated transcriptional silencing. Mapping of regions showing decreased H3K9me3 signal upon Piwi knockdown along the Drosophila melanogaster genome (outer circle). Transposon density is shwon in the inner circle.