National Engineering Laboratory for Tree Breeding, Beijing Forestry University, No. 35 Qinghua East Road, Beijing 100083, People's Republic of China.
Plant Cell Rep. 2012 Aug;31(8):1393-405. doi: 10.1007/s00299-012-1255-7. Epub 2012 Apr 4.
The andromonoecious poplar is an exceptional model system for studying sex-specific flower development in dioecious plants. There is increasing evidence that epigenetic regulation, particularly DNA methylation, is an important regulatory factor during flower development. Here, methylation-sensitive amplified polymorphism (MSAP) was used to screen for sex-specific DNA methylation alterations in the andromonoecious poplar. The sequences of 27 sex-specific amplified fragments were obtained from DNA prepared from sex-specific flower tissues. PtGT2, PtPAL3, and PtCER4, which are homologous to MF26, MF29, and MF35, respectively, were cloned as candidate genes. Expression analysis and DNA methylation pattern profiling of the three candidate genes revealed that gene expression upregulation was always associated with gene body methylation. The results suggested that DNA methylation sites have the potential to regulate the genes' transcript levels. These three genes were shown to play important roles during different phases of flower development. This study will help to provide candidates for future experiments aimed at understanding the mechanism, whereby DNA methylation regulates gene expression in poplar.
We report the first screen for sex-specific DNA methylation alterations in the andromonoecious poplar. 27 sex-specific methylation sites were identified. The gene expression levels and DNA methylation patterns were detected for three candidate genes.
雌雄同株杨树是研究雌雄异株植物中性别特异性花发育的特殊模式系统。越来越多的证据表明，表观遗传调控，特别是 DNA 甲基化，是花发育过程中的一个重要调控因子。在这里，使用甲基化敏感扩增多态性（MSAP）筛选雌雄同株杨树中的性别特异性 DNA 甲基化改变。从性别特异性花组织中制备的 DNA 中获得了 27 个性别特异性扩增片段的序列。PtGT2、PtPAL3 和 PtCER4 分别与 MF26、MF29 和 MF35 同源，被克隆为候选基因。对三个候选基因的表达分析和 DNA 甲基化模式分析表明，基因表达上调总是与基因体甲基化相关。结果表明，DNA 甲基化位点有可能调节基因的转录水平。这三个基因在花发育的不同阶段发挥重要作用。这项研究将有助于为未来旨在了解 DNA 甲基化如何调节杨树中基因表达的实验提供候选基因。
我们报告了在雌雄同株杨树中首次筛选性别特异性 DNA 甲基化改变。鉴定了 27 个性别特异性甲基化位点。检测了三个候选基因的基因表达水平和 DNA 甲基化模式。
