| 摘要 |
This invention concerns recombinant RNA molecules comprising a recognition sequence for the binding of an RNA-directed RNA polymerase, a sequence for the initiation of product strand synthesis and a heterologous sequence of interest inserted at a specific site in the internal region of the recombinant molecule. Such recombinant RNA molecules are capable of serving as a template for the synthesis of complementary single-stranded molecules by RNA-directed RNA polymerase. The product molecules so formed are also capable of serving as a template for the synthesis of additional copies of the original recombinant RNA molecule. In a preferred embodiment of the invention ~.beta. replicase is used as the RNA-directed RNA polymerase. The invention also concerns methods of selectively cleaving RNA molecules at specific sites, methods of constructing recombinant RNA molecules, and methods for the autocatalytic in vitro replication of recombinant RNA molecules. The recombinant RNA molecules of this invention, or fragments thereof, are useful in methods of sequencing nucleic acids, as hybridization probes, as labels, in cell-free methods of protein synthesis, in methods for identifying or characterizing RNA processing enzymes, in methods for producing mutant viruses or viroids and in isolating from mRNA mixtures a desired mRNA in the form of a recombinant mRNA molecule.
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