Distinct Functions for the Drosophila piRNA Pathway in Genome Maintenance and Telomere Protection
Figure 4
piRNAs linked to a 4th chromosome cluster containing telomeric transposon fragments.
A. Length histograms showing plus genomic strand (blue) and minus genomic strand (red) mapping piRNAs in wt, armi, aub, rhi and ago3 mutants. The relative abundance is normalized to sequencing depth and is plotted on the y-axis. Note that sense strand of the transposon fragments in this cluster are on the minus genomic strand, and that the scales differ. Preferential loss of shorter piRNAs from aub and armi leads to a prominent endo-siRNA peak at 21 nt (marked by a black arrow). B. Abundance of longer (23–29 nt) plus strand (blue) and minus strand (red) piRNAs in the indicated mutants relative to their respective wild-type controls. All four mutations reduce plus strand piRNAs, which are anti-sense to the telomeric transposons. C. 19–22 nt genomic plus and minus strand piRNAs in the indicated mutants. All four mutations reduce plus strand RNAs. However, minus strand species are retained at near wild type levels in both rhi and ago3 mutants. For panels B and C, bars show normalized reads in mutants divided by normalized reads in wild-type controls.