Figure 2. 21U-RNAs are expressed in the C. elegans germ line.
(A and B) Northern blot analysis of 21U-RNA-1 and 21U-RNA-3442 small RNAs. The SL1 precursor is shown as a loading control. In (A), RNA was generated from synchronized wild-type populations at distinct developmental stages. In (B) RNA generated from wild-type worms was compared to RNA obtained from strains with no germline: glp-4(bn2) and eft-3(q145); a male-only population: fog-2(q71); and a population of worms with no sperm: fem-1(hc17). (C) The expression profile for the bulk population of 21U-RNAs as determined by large-scale sequencing. The percent of reads from each library with 21U-RNA identity are shown. Light blue libraries were prepared for sequencing with Rnl2(1−249) ligase, dark blue with T4 RNA ligase 1 (see methods).