Differential expression of Xenopus laevis miRNAs and pri-miRNAs. Total RNA was isolated from X. laevis oocytes and adult tissues were resolved on denaturing polyacrylamide gels, electroblotted to nylon membranes, and hybridized with DNA oligonucleotides complementary to computationally identified Xenopus miRNAs. Specific Xenopus miRNAs sequences probed are indicated at the top and detected miRNA transcripts indicated at right. Xenopus tissues extracted for RNA analysis are indicated at the top. (M) muscle; (L) liver; (O) oocyte; (SK) skin; (SP) spleen; (K) kidney; (H) heart. (A) Differential expression of Xenopus laevis miRNAs located on the 5′ and 3′ arms of the same pre-miRNA. The folded structure of these pre-miRNAs is illustrated. (B) Tissue-specific expression of Xenopus laevis miRNAs. (C) Tissue-specific expression of Xenopus laevis miRNAs clustered on the same pre-miRNA transcript. (D) Differential expression of transcribed Xenopus laevis pri-miRNA precursors at the level of pre-miRNA and/or miRNA processing.
