基于ISSR分子标记技术的山核桃幼胚DNA甲基化初步研究

用简单序列重复区间扩增(inter-simple sequence repeat,ISSR)DNA分子标记技术对山核桃Carya cathayensis不同发育阶段幼胚(第9周至13周)的DNA进行甲基化状态检测。结果表明:17个引物在各个发育时期山核桃幼胚样品中共扩增检测到的128个甲基化位点。甲基化比例随着幼胚的发育逐渐升高,5个时期幼胚甲基化比例依次为23.44%,25.78%,28.90%,40.62%和42.19%。进一步研究表明:5个时期均存在全甲基化位点和半甲基化位点,其中,全甲基化位点所占比例分别为7.81%,8.59%,16.40%,24.22%和25.00%;半甲基化位点所占分别为15.62%,17.19%,12.50%,16.41%,17.19%。因此,山核桃幼胚5个发育时期在基因组DNA甲基化水平上存在着较大差异(P<0.01)。

ISSR analysis of DNA methylation variety on immature embryos of Carya cathayensis

To evaluation the methylation status of different immature embryo stages of Carya cathayensis, DNA methylation variety was detected on immature embryos of Carya cathayensis, and an inter-simple sequence repeat （ISSR） analysis was performed to reveal the DNA methylation in five developmental stages of immature embryos （9 - 13 weeks post pollination）. Results revealed 128 bands obtained from 17 primers. With development of the immature embryos, the methylation percentage from 9 to 13 weeks post pollination increased gradually from 23.4% to 25.8%, 28.9%, 40.6%, and then 42.2%. Also, total DNA methylation （7.8%, 8.6%, 16.4%, 24.2%, and 25.0%） and half DNA methylation （15.6%, 17.2%, 12.5%, 16.4%, and 17.2%） existed. Thus, there was DNA methylation variety with the development of the immature embryos of Carya cathayensis（P＜0.01）.［Ch, 3 fig. 5 tab. 21 ref.］