Wassenegger M, Heimes S, Riedel L, Sänger H L
Max-Planck-Institut für Biochemie, Abteilung Viroidforschung, Martinsried, Federal Republic of Germany.
Cell. 1994 Feb 11;76(3):567-76. doi: 10.1016/0092-8674(94)90119-8.
One monomeric and three oligomeric potato spindle tuber viroid (PSTVd) cDNA units were introduced into the tobacco genome via the Agrobacterium-mediated leaf-disc transformation. Southern analysis of the integrates revealed that only their PSTVd-specific sequences become fully methylated, whereas the flanking T-DNA and the genomic plant DNA remain unaltered. Viroid cDNA methylation could only be observed after autonomous viroid RNA-RNA replication had taken place in these plants. These findings demonstrate that a mechanism of de novo methylation of genes might exist that can be induced and targeted in a sequence-specific manner by their own mRNA.
通过农杆菌介导的叶盘转化法，将一个单体和三个寡聚体马铃薯纺锤块茎类病毒（PSTVd）cDNA单元导入烟草基因组。对整合体的Southern分析表明，只有其PSTVd特异性序列完全甲基化，而侧翼T-DNA和植物基因组DNA保持不变。只有在这些植物中发生自主类病毒RNA-RNA复制后，才能观察到类病毒cDNA甲基化。这些发现表明，可能存在一种基因从头甲基化机制，该机制可以被其自身的mRNA以序列特异性方式诱导并靶向。
