Shan X H, Li Y D, Liu X M, Wu Y, Zhang M Z, Guo W L, Liu B, Yuan Y P
College of Plant Science, Jilin University, Changchun, P.R. China.
Genet Mol Res. 2012 Aug 17;11(3):2749-59. doi: 10.4238/2012.August.17.2.
We analyzed genetic diversity and population genetic structure of four artificial populations of wild barley (Hordeum brevisubulatum); 96 plants collected from the Songnen Prairie in northeastern China were analyzed using amplified fragment length polymorphism (AFLP), specific-sequence amplified polymorphism (SSAP) and methylation-sensitive amplified polymorphism (MSAP) markers. Indices of (epi-)genetic diversity, (epi-)genetic distance, gene flow, genotype frequency, cluster analysis, PCA analysis and AMOVA analysis generated from MSAP, AFLP and SSAP markers had the same trend. We found a high level of correlation in the artificial populations between MSAP, SSAP and AFLP markers by the Mantel test (r > 0.8). This is incongruent with previous findings showing that there is virtually no correlation between DNA methylation polymorphism and classical genetic variation; the high level of genetic polymorphism could be a result of epigenetic regulation. We compared our results with data from natural populations. The population diversity of the artificial populations was lower. However, different from what was found using AFLP and SSAP, based on MSAP results the methylation polymorphism of the artificial populations was not significantly reduced. This leads us to suggest that the DNA methylation pattern change in H. brevisubulatum populations is not only related to DNA sequence variation, but is also regulated by other controlling systems.
我们分析了野生大麦（短芒大麦草）四个人工种群的遗传多样性和群体遗传结构；利用扩增片段长度多态性（AFLP）、特异序列扩增多态性（SSAP）和甲基化敏感扩增多态性（MSAP）标记，对从中国东北松嫩草原采集的96株植物进行了分析。由MSAP、AFLP和SSAP标记产生的（表观）遗传多样性、（表观）遗传距离、基因流、基因型频率、聚类分析、主成分分析和方差分析指标具有相同趋势。通过Mantel检验，我们发现人工种群中MSAP、SSAP和AFLP标记之间存在高度相关性（r>0.8）。这与之前的研究结果不一致，之前的研究表明DNA甲基化多态性与经典遗传变异之间几乎没有相关性；高水平的遗传多态性可能是表观遗传调控的结果。我们将我们的结果与自然种群的数据进行了比较。人工种群的群体多样性较低。然而，与使用AFLP和SSAP的结果不同，基于MSAP结果，人工种群的甲基化多态性没有显著降低。这使我们认为，短芒大麦草种群中DNA甲基化模式的变化不仅与DNA序列变异有关，还受其他控制系统的调控。
