Down-regulation of gene expression using artificial microRNAs

摘要

Isolated nucleic acid fragments comprising precursor miRNAs, and artificial miRNAs and their use in down-regulating gene expression are described.

主权项

1. An isolated nucleic acid fragment encoding an artificial microRNA (amiRNA) precursor, said fragment comprising a deoxyribonucleotide sequence wherein (i) nucleotides 196 to 216 of SEQ ID NO:17 are replaced by a first variable nucleotide subsequence ranging in size from 19 to 24 nucleotides depending upon a target sequence whose expression is to be reduced, (ii) nucleotides 262 to 282 of SEQ ID NO:17 are replaced by a second variable nucleotide subsequence ranging in size from 19 to 24 nucleotides, said second variable nucleotide subsequence being capable of hybridizing to the first variable subsequence, and (iii) the amiRNA precursor produced by said isolated nucleic acid fragment has the same stem structure as the precursor miRNA produced by endogenous SEQ ID NO:17.