Reactivation of a silenced minimal Mutator transposable element system following low-energy nitrogen ion implantation in maize
Reactivation of a silenced minimal Mutator transposable element system following low-energy nitrogen ion implantation in maize
复制标题
低能氮离子植入玉米后沉默的最小突变转座元件系统的重新激活
DOI：
10.1007/s00299-010-0922-9
复制
发表时间：
2010-12-01
影响因子：
6.2
通讯作者：
Cheng, Beijiu
中科院分区：
文献类型：
--
作者：
Qian, Yexiong;Cheng, Xiao;Cheng, Beijiu
在玉米中，突变体转座元件在基因组中要么是活跃的，要么是沉默的。作为对环境胁迫的响应，沉默的突变子元件可以被重新激活，导致基因组结构和基因功能的变化。然而，没有直接的实验证据表明环境胁迫与突变体转座子重新激活有关。利用一个含有单个非活性MuDR和一个非自主突变元件的玉米品系，即在一个非活性突变背景中隐性报告等位基因A1-Mum2中插入一个MU1，我们直接评估了低能氮离子注入后突变体的重新激活。我们观察到，N(+)注入减少了MuDR末端反向重复序列中的胞嘧啶甲基化，并增加了Mudra和MudrB的表达。这两个变化都与MuDR通过重新激活不活跃的最小突变体转座元件系统而增加的转座活性有关。本研究为环境胁迫因子与玉米突变体转座子动员之间的联系提供了直接证据。此外，观察到的DNA甲基化的变化表明了低能离子注入突变的一种新机制。
In maize, Mutator transposable elements are either active or silenced within the genome. In response to environmental stress, silenced Mutator elements could be reactivated, leading to changes in genome structure and gene function. However, there is no direct experimental evidence linking environmental stress and Mutator transposon reactivation. Using a maize line that contains a single inactive MuDR and a lone nonautonomous Mutator element, a Mu1 insertion in the recessive reporter allele a1-mum2 in an inactive Mutator background, we directly assessed Mutator reactivation following low-energy nitrogen ion implantation. We observed that N(+) implantation decreased cytosine methylation in MuDR terminal inverted repeats and increased expression of mudrA and mudrB. Both changes were associated with increased transpositional activity of MuDR through reactivation of the inactive minimal Mutator transposable element system. This study provides direct evidence linking environmental stress agents and Mutator transposon mobilization in maize. In addition, the observed changes to DNA methylation suggest a new mechanism for mutations by low-energy ion implantation.