Knockdown of shu causes loss of cluster-derived piRNAs in both somatic and germline tissues. (A) At the top is shown a histogram of small RNAs mapping to the germline-specific 42AB cluster in flies expressing the indicated dsRNAs specifically in germ cells. In the middle, the size distribution of RNAs derived from each strand of the 42AB and flamenco clusters is shown as a histogram. At the bottom are histograms reflecting the relative enrichment of RNAs overlapping by the indicated number of nucleotides, plotted by Z-score, for the 42AB and flamenco clusters in the indicated knockdown animals. The peak at position 9 (arrow) is indicative of a ping-pong interaction. (B) A histogram shows relative piRNA levels for a series of germline and somatic clusters. Total reads were normalized across libraries to piRNAs mapping to flamenco, which is unaffected in germline-specific knockdowns. For each cluster, changes in mapping piRNAs are shown with reference to the white control, which is set to 100%. C and D are similar to A and B except that dsRNA expression is driven by a follicle cell–specific tj-GAL4 driver. In C, at the top, reads are shown mapping to the soma-specific flamenco cluster. In D, reads are normalized across libraries to those derived from 42AB, whose activity is not affected in the soma-specific knockdown.
