Analysis of DNA methylation in different maize tissues
Analysis of DNA methylation in different maize tissues
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DOI：
10.1016/s1673-8527(08)60006-5
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发表时间：
2008-01-01
影响因子：
5.9
通讯作者：
Cao, Moju
中科院分区：
文献类型：
--
作者：
Lu, Yanli;Rong, Tingzhao;Cao, Moju
DNA甲基化在植物生物发育和组织分化过程中的基因表达调控中起着重要作用。本研究采用甲基化敏感扩增片段长度多态性（methylation-sensitive Amplified fragment length polymorphism，AFLP）技术，对玉米自交系18白色和18红色的雄穗、苞叶和穗部叶片的CCGG位点DNA甲基化水平进行了比较，并对3种组织的特异性甲基化模式进行了分析。三种组织中胞嘧啶甲基化水平差异显著，两个自交系的变化趋势相同。甲基化敏感扩增多态性（methylation sensitive amplification polymorphism，MSAP）比率和全甲基化水平均以苞叶最高，雄穗最低。同时，在来自自交系18号白色和18号红色的相同组织中观察到不同的甲基化水平。玉米基因组内胞嘧啶完全甲基化是主要的甲基化类型。观察三种组织中的差异甲基化模式。此外，对9个差异甲基化片段的测序和随后的blast搜索显示，胞嘧啶甲基化的5' -CCGG-3'序列分布在编码区和非编码区的重复序列中。采用Southern杂交技术验证甲基化多态性。这些结果清楚地证明了MSAP技术用于玉米基因组中大规模DNA甲基化检测的能力，以及植物生长和发育过程中DNA甲基化变化的复杂性。不同的甲基化水平可能与不同组织中特定基因的表达有关。
DNA methylation plays an important role in gene expression regulation during biological development and tissue differentiation in plants. This study adopted methylation-sensitive Amplified fragment length polymorphism (AFLP) to compare the levels of DNA cytosine methylation at CCGG sites in tassel, bracteal leaf, and ear leaf from maize inbred lines, 18 White and 18 Red, respectively, and also examined specific methylation patterns of the three tissues. Significant differences in cytosine methylation level among the three tissues and the same changing tendency in two inbred lines were detected. Both MSAP (methylation sensitive amplification polymorphism) ratio and full methylation level were the highest in bracteal leaf, and the lowest in tassel. Meanwhile, different methylation levels were observed in the same tissue from the inbred lines, 18 White and 18 Red. Full methylation of internal cytosine was the dominant type in the maize genome. The differential methylation patterns in the three tissues were observed. In addition, sequencing of nine differentially methylated fragments and the subsequent blast search revealed that the cytosine methylated 5' -CCGG-3' sequences were distributed in repeating sequences, in the coding and noncoding regions. Southern hybridization was used to verify the methylation polymorphism. These results clearly demonstrated the power of the MSAP technique for large-scale DNA methylation detection in the maize genome, and the complexity of DNA methylation change during plant growth and development. The different methylation levels may be related to specific gene expression in various tissues.