Patent ID: 8143061

Claim:
A method for producing a heterologous RNA of interest, comprising: (1) transforming mitochondria of a yeast cell lacking mitochondrial DNA with a mitochondrial transcription vector that comprises at least one copy of the DNA encoding said heterologous RNA of interest under the control of regulatory element(s) for mitochondrial transcription, and a mitochondrial transformation reporter gene or a fragment of said reporter gene, (2) identifying a yeast mitochondrial transformant obtained in (1) which has mitochondria comprising the mitochondrial transcription vector but no mitochondrial DNA, wherein the only RNAs which are produced in said mitochondria by said mitochondrial transcription vector, are the heterologous RNA of interest alone, when the reporter gene or the fragment thereof are not transcribed, or the heterologous RNA of interest and the transcript of the reporter gene or reporter gene fragment, when said reporter gene or fragment thereof are transcribed; (3) culturing the yeast mitochondrial transformant selected in (2), (4) isolating the mitochondria from the yeast mitochondrial transformant obtained in (3), and (5) extracting and purifying the heterologous RNA of interest from said mitochondria.