不同倍性(2×、3×、4×)鸭梨基因组DNA甲基化水平与模式分析

Analyzing the Levels and Patterns of DNA Methylation in Yali Pear Autopolyploid

以鸭梨(Pyrus.bretschneideri Rehd.cv.‘Yali')多倍体(2×、3×、4×)为材料,应用甲基化敏感扩增多态性(methylation sensitive amplified polymorphism,MSAP)技术研究不同倍性鸭梨基因组DNA甲基化水平及模式变化.共筛选22对引物,平均每对引物产生约50条带,统计100～500 bp的扩增带,共计954个位点.分析表明:鸭梨2×、3×、4×分别检测到831、886、852个位点,发生甲基化位点分别占15.5%、20.0%、16.8%,其中全甲基化占9.7%、11.9%、9.7%.分析这些位点甲基化模式表明:甲基化模式在三个倍性间类型相同的占所检测位点的69.2%,仅两种倍性相同的为25.4%,各不相同的占5.5%,其中三倍体41.4%甲基化位点发生改变,显示出独特的DNA甲基化特点.

The methylation-sensitive amplification polymorphism（MSAP）is used to analyze the levels and patterns of methylation in Yali pear autopolyploid（Pyrus.bretschneideri Rehd. cv.＇Yali＇）.We select twenty-two primers combinations to reveal the cytosine methylation polymorphism among the autopolyploid（2×,3×,4×）.And it amount to 954 sites from 100 to 500 bp on the gel electrophoresis.It is suggested that the identified sites of diploid,triploid and tetraploid is 831,886 and 852,and the percentage of total methylation sites of the three autopolyploid is 15.5%,20.0%,16.8%respectively.Fully methylation rate of them is 9.7%, 11.9%,9.7%.The percentage of the same cytosine methylation patterns among the autopolyploid is 69.2%,and the different patterns is 5.5%.The rate that one autopolyploid methylation patterns is identical to another is 25.4%.And 41.4%of methylation cytosine patterns in the offspring（triploid）differ from that of the parents（diploid and tetraploid）.