Division of Molecular and Cellular Biology, Department of Supramolecular Biology, Graduate School of Nanobioscience, Yokohama City University, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
Nucleic Acids Res. 2012 Dec;40(22):e173. doi: 10.1093/nar/gks765. Epub 2012 Aug 16.
Gene downregulation by antisense morpholino oligonucleotides (MOs) is achieved by either hybridization around the translation initiation codon or by targeting the splice donor site. In the present study, an antisense MO method is introduced that uses a 25-mer MO against a region at least 40-nt upstream from a poly(A) tail junction in the 3'-untranslated region (UTR) of maternal mRNA. The MO removed the poly(A) tail and blocked zebrafish cdk9 (zcdk9) mRNA translation, showing functional mimicry between miRNA and MO. A PCR-based assay revealed MO-mediated specific poly(A) tail removal of zebrafish mRNAs, including those for cyclin B1, cyclin B2 and tbp. The MO activity targeting cyclins A and B mRNAs was validated in unfertilized starfish oocytes and eggs. The MO removed the elongated poly(A) tail from maternal matured mRNA. This antisense method introduces a new application for the targeted downregulation of maternal mRNAs in animal oocytes, eggs and early embryos.
反义吗啉代寡核苷酸（MOs）通过翻译起始密码子周围的杂交或靶向剪接供体位点来实现基因下调。在本研究中，引入了一种反义 MO 方法，该方法使用针对多聚（A）尾连接在 3'非翻译区（UTR）中至少 40 个核苷酸上游的区域的 25 个核苷酸 MO。该 MO 去除了多聚（A）尾并阻断了斑马鱼 cdk9（zcdk9）mRNA 的翻译，显示 miRNA 和 MO 之间的功能模拟。基于 PCR 的分析显示 MO 介导的斑马鱼 mRNA 的特异性多聚（A）尾去除，包括 cyclin B1、cyclin B2 和 tbp。针对 cyclins A 和 B mRNA 的 MO 活性在未受精卵的海星卵母细胞和卵中得到验证。该 MO 从母体成熟 mRNA 中去除了延长的多聚（A）尾。这种反义方法为在动物卵母细胞、卵子和早期胚胎中靶向下调母体 mRNA 引入了一种新的应用。
