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以萌动期与展叶期的叶籽银杏和银杏为试材,采用基于DNA甲基化敏感扩增多态性分析(Methylation-sensitive amplification polymorphism,MSAP)方法,在全基因组水平上探究叶籽银杏、银杏不同发育期DNA序列中CCGG位点的甲基化水平及模式变化特征。萌动期选用22对引物,在叶籽银杏和银杏中检测到扩增位点为498和384个,甲基化位点为237和165个,其总甲基化率分别为47.6%和42.4%;展叶期选用40对引物,在叶籽银杏有叶生胚珠(YZ2)、无叶生胚珠(YC)及银杏(CK)叶片中检测到扩增位点767、600及367个,甲基化位点分别为370、244及152个,其总甲基化率分别为48.3%、40.5%及41.5%。进一步对不同发育期叶籽银杏、银杏DNA甲基化模式的变化特征进行分析,结果显示:萌动期、展叶期叶籽银杏与银杏相比均有超过半数的位点(52.1%、54.6%及64.2%)DNA甲基化模式发生多态性变化,萌动期叶籽银杏相对于银杏其变化趋势以超甲基化为主;展叶期叶籽银杏有叶生胚珠相对于叶籽银杏无叶生胚珠及银杏甲基化的变化趋势以超甲基化为主,叶籽银杏有叶生胚珠相对于银杏DNA甲基化模式变异幅度更大,超甲基化水平更高,显示出叶籽银杏基因组独特的DNA甲基化特征。
The leaves of Ginkgo biloba and Ginkgo biloba were used as materials during germination and leaf expanse. Methylation-sensitive amplification polymorphism (MSAP) method was used to explore the genetic level of Ginkgo biloba , The gingko DNA at different developmental stages of CCGG methylation levels and pattern changes. In the germinating period, 22 pairs of primers were selected and 498 and 384 amplification sites were detected in the leaves of Ginkgo biloba and Ginkgo biloba. The number of methylation sites was 237 and 165, respectively. The total methylation rates were 47.6% and 42.4% 40 pairs of primers were selected at the leaf-setting stage, and 767, 600 and 367 amplification sites were detected in leaves of YZ2, leafless ovule (YC) and ginkgo (CK) 370,244 and 152, respectively. The total methylation rates were 48.3%, 40.5% and 41.5% respectively. Further analysis of the DNA methylation patterns of Ginkgo biloba and Ginkgo biloba at different developmental stages revealed that more than half of the Ginkgo biloba leaves (52.1%, 54.6% And 64.2%, respectively). The changes of DNA methylation patterns in ginkgo seedlings during the germination period were mainly hypermethylation. The trend of methylation of leaf ovule and gingko was mainly hypermethylation. The variation of methylation pattern of leaf ovule and leaf ginkgo has more variation with DNA methylation pattern and the hypermethylation level is higher, The unique DNA methylation characteristics of Ginkgo biloba genome.