| 主权项 |
1. A method for reducing or eliminating expression of a target gene encoding a biological substance in an Aspergillus niger strain, an Aspergillus oryzae strain, or a Trichoderma reesei strain, comprising:
(a) inserting into the genome of the Aspergillus niger strain, the Aspergillus oryzae strain, or the Trichoderma reesei strain a double-stranded transcribable nucleic acid construct comprising a promoter operably linked to a first polynucleotide comprising a first transcribable region with homology to the target gene or a homologue thereof encoding the biological substance and a second polynucleotide comprising a second transcribable region with no effective homology to the target gene or the homologue thereof, wherein the second transcribable region comprises two segments complementary to each other in reverse orientation relative to each other and the first and second transcribable regions are transcribed as a single mRNA molecule; and (b) inducing production of short interfering RNAs (siRNAs), comprising sequences of the target gene to be silenced by the process of transitive RNAi, by cultivating the Aspergillus niger strain, the Aspergillus oryzae strain, or the Trichoderma reesei strain under conditions to produce RNA transcripts of the double-stranded transcribable nucleic acid construct that are then converted to the siRNAs, which interact with RNA transcripts of the target gene or the homologue thereof to reduce or eliminate expression of the target gene or the homologue thereof encoding the biological substance. |
