A linear double-stranded RNA in Trichomonas vaginalis.
A "double-stranded" RNA was identified in the anaerobic, parasitic protozoan Trichomonas vaginalis. Electron microscopic evidence indicated linear double-stranded structure 1.5 micron in length, with no apparent hairpins or loops. Boiling in 30% dimethyl sulfoxide denatured it into single strands of 1.5 micron and shorter fragments. It consists of 23.4% G, 23.4% C, 23.0% A, and 30.3% U and melts at a transition temperature of 81.7 degrees C in 75 mM NaCl and 7.5 mM sodium citrate, pH 7.0, with 7-15% hyperchromicity. The 32P-labeled double-stranded RNA hybridized specifically with T. vaginalis DNA fragments in a single DNA band from EcoRI digest and two DNA bands from HindIII digest. Of the 33 different strains or isolates of T. vaginalis examined, all contained this double-stranded RNA. However, the only two metronidazole-resistant T. vaginalis strains examined thus far (IR78 and 85) contained no detectable double-stranded RNA, although the corresponding DNA sequence was present. DNA fragments of Escherichia coli and Giardia lamblia did not hybridize with the double-stranded RNA. But DNA fragments of a metronidazole-sensitive Tritrichomonas foetus hybridized specifically with the double-stranded RNA, even though this organism does not contain the double-stranded RNA itself.
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D000818:Animals; D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D004996:Ethidium; D009693:Nucleic Acid Hybridization; D012330:RNA, Double-Stranded / Q000032:analysis*; D014246:Trichomonas vaginalis / Q000235:genetics*
D012330:RNA, Double-Stranded; D004247:DNA; D004262:DNA Restriction Enzymes; D004996:Ethidium