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[摘要]
目的 分析半夏多倍体复合体DNA甲基化状态的变化(甲基化水平和甲基化差异模式)。方法 应用甲基化敏感扩增多态性(methylation sensitive amplified polymorphism,MSAP)技术,采用34对引物进行选择性扩增。结果 扩增共得到7708条带,其中5636条带为甲基化多态性带在半夏7倍、8倍、9倍、10倍体值株间DNA甲基化水平变化不大。总扩增位点甲基化水平在54%~58%,全甲基化率为24.1%~24.3%,高倍性植株甲基化程序相应比较高。除甲基化水平稍有变化外,半夏不同倍性株间的DNA甲基化模式也形式各异,检测到的带型分为两大类(和型)。其中,不同倍性间DNA甲基化状态保持不变的位点占52.5%,归为型;少部分检测位点(占47.5%,归为型)的DNA甲基化模式在不同倍性间存在显著差异。结论 半夏多倍体复合体各倍性植株间存在大量的胞嘧啶甲基化变异且整体甲基化水平较高。
[Key word]
[Abstract]
Objective To analyze the DNA methylation status of polyploid complex of Pinellia ternata. Methods Methylation sensitive amplified polymorphism(MSAP) technique was carried out to analyze the methylation status of polyploid complex of P.ternata. Thirty-four selective primer amplifications were used to check the status of cytosine methylation DNA samples. Results A total of 7 708 bands were obtained.Among them 5 636 bands,each representing a recognition site cleaved by one or both of the isoschizomers(Hpa Ⅱ and Msp Ⅰ),were amplified.Furthermore,methylation patterns varied among the four polyploids:heptaploid,octoploid,nonuploid,and decaploid.Total and full methylation levels in P.ternata were 54%-58% and 24.1%-24.3%.All types of MSAP patterns detected in the study belonged to two classes,type Ⅰ and Ⅱ. 52.5% of detected bands belonged to Type Ⅰ; Another 47.5% were type Ⅱ,which showed the methylation differences among the four polyploids. Conclusion The results demonstrate DNA methylation events occur in P.ternata and the general methylation levels are higher.
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[基金项目]
教育部博士点基金项目(20040023022)