Abstract: The invention provides a method for changing the genetic properties of an eukaryotic organism by suppression of expression of a target gene. Proposed method can be used in gene-therapy in medicine, agriculture, or industrial biotechnology. Genetic properties of an eukaryotic organism are changed by gene-specific silencing of a selected gene using small RNA molecules, that are complementary in a parallel orientation (pcRNAs) to mRNA of the selected gene; wherein pcRNAs are synthesized in vivo or in vitro on the artificial DNA sequence encoding pcRNA, said artificial DNA sequence possesses symmetrical nucleotide ordering (mirror inversion) in respect to the nucleotide sequence of the gene.