光照诱导广叶绣球菌基因组甲基化分析

Light Induced DNA Methylation in Sparassis latifolia Mycelium

利用荧光标记甲基化敏感扩增多态性技术(fluorescence-labeled methylation-sensitive amplified polymorphism,F-MSAP)比较广叶绣球菌(Sparassis latifolia)菌丝在光、暗条件下基因组胞嘧啶甲基化的变化。F-MSAP分析显示,15对选择性扩增引物共扩增出6383个CCGG位点,平均每个处理每对引物扩增47个条带,其中2849条片段发生甲基化。黑暗组、光照24h和光照48h处理组总甲基化水平分别是49.54%、41.71%和42.88%,黑暗组和光照处理组的总甲基化水平差异显著(P<0.01),而光照组间甲基化水平差异不显著(P=0.10)。与黑暗组相比,光照诱导全甲基化率升高,半甲基化率降低,差异显著(P<0.01)。总的趋势是光照引起广叶绣球菌菌丝DNA去甲基化。

Sparassis latifolia mycelia were grown on potato dextrose agar for 20 d in darkness and then incubated as follows： （ I ） a further 48 h in the dark, （II） exposed to light （300 Ix） for 24 h and （ III ） exposed to light （300 Ix） for 48 h. DNA methylation levels and patterns in mycelia subjected to the three different dark/light regimes were then analyzed using fluorescence-labeled methylation-sensitive amplified polymorphism （F-MSAP） ~ A total of 6383 CCGG sites were detected, including 2849 methylated sites, using 15 selective primer pairs, equivalent to approximately 47 sites per replicate sample （n = 3） for each primer pair. Total methylation ratios for the three treatments were 49.54%, 41.71% and 42.88%, respectively. Differences in the total methylation ratios between dark and light treatments were significant （P〈0.01）, but the difference between the 24 h and 48 h light treatments was not significant （P = 0.1）. Full-methylation levels increased and hemi-methylation levels decreased （P〈 0.01） in mycelia exposed to light compared to unexposed samples. Our data indicate that exposure to light induced DNA demethylation in S. latifolia mycelium.