摘要
Dear Editor, The maize Mutator （MuDRIMu） transposon family is the most active DNA transposon in plants （Lisch, 2002）. The Mu family contains diverse elements, all sharing similar -215-bp terminal inverted repeats （TIRs）. MuDR is the autonomous element, and a transcriptionally active MuDR is required for transposition of the non-autonomous Mu elements （Chomet et al., 1991）. MuDR contains two genes, mudrA and mudrB （Figure 1A）; mudrA encodes the MURA transposase, and mudrB encodes a protein with unknown function. To avoid the deleterious effects of transposons, plants have acquired mechanisms to epigenetically silence them. Silenced Mu ele- ments become heavily methylated, and their reactivation is very rare. To date, only UV-B radiation treatments have reac- tivated silenced Mu （Walbot, 1999）.
Dear Editor, The maize Mutator （MuDRIMu） transposon family is the most active DNA transposon in plants （Lisch, 2002）. The Mu family contains diverse elements, all sharing similar -215-bp terminal inverted repeats （TIRs）. MuDR is the autonomous element, and a transcriptionally active MuDR is required for transposition of the non-autonomous Mu elements （Chomet et al., 1991）. MuDR contains two genes, mudrA and mudrB （Figure 1A）; mudrA encodes the MURA transposase, and mudrB encodes a protein with unknown function. To avoid the deleterious effects of transposons, plants have acquired mechanisms to epigenetically silence them. Silenced Mu ele- ments become heavily methylated, and their reactivation is very rare. To date, only UV-B radiation treatments have reac- tivated silenced Mu （Walbot, 1999）.
