FIG. 3.

Sizes of short RNAs produced by dsRNA processing in vitro and detected in vivo. (a) Twenty-one- to 23-nt RNA fragments of lacZ and Su(Ste) are produced by dsRNA processing in cell culture and testis extracts. In vitro-synthesized, uniformly labeled lacZ or Su(Ste) dsRNAs were incubated with cell culture or testis extracts, and RNAs were isolated and separated on a 15% denaturing acrylamide gel. Total testis RNA from wild-type males was separated in parallel. ³²P-labeled RNA oligonucleotides were used as size markers. (b) The same gel was electroblotted to a membrane and hybridized with a Su(Ste) probe to detect the 25- to 27-nt Su(Ste) RNA in the total testis RNA preparation. Hybridization also increased the strength of signals from the in vitro-synthesized Su(Ste) dsRNA.