Figure 1. Northern blots of small RNA transcripts. (A through C) Total RNA from C. elegans larvae (stages L1 through L4) or from mixed stage (M) populations were blotted and probed with oligonucleotides complementary to either the 5' or 3' half of the indicated transcript (13). U6 = the same filters were probed with probe to U6 snRNA as a loading control. (A)
mir-60 5' probe detects a transcript of ~65 nt. The ratio of L1 to L4
mir-60 signal, normalized to U6, is about 5:1. The
mir-60 3' probe (not shown) detects a similar-sized species with a similar developmental profile. (B)
mir-80 3' probe detects a ~22-nt RNA expressed uniformly at all stages. (C)
mir-52 5' probe. The normalized
mir-52 signal is threefold greater in the L1 versus the L3. (D)
mir-1 3' probe detects a transcript of ~22 nt in total RNA from mouse (Mm) 17-day embryos, mixed-stage C. elegans (Ce), Drosophila melanogaster (Dm) mixture of embryo-larvae-pupae, and in a sample of human heart (ht) tissue. Other human tissue samples were brain (br), liver (li), kidney (ki), and lung (lu). (E)
mir-1 and
mir-58 probes to total RNA from mixed populations of wild-type (+) and
dcr-1(
ok247) (-) animals. An increase in the proportion of unprocessed ~65-nt precursor is observed in the
dcr-1 RNA.