Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg 69120, Germany.
J Exp Biol. 2013 Apr 15;216(Pt 8):1423-9. doi: 10.1242/jeb.080754. Epub 2012 Dec 21.
DNA methylation is a widely conserved epigenetic modification. The analysis of genome-scale DNA methylation patterns in various organisms suggests that major features of animal methylomes are widely conserved. However, based on the variation of DNA methyltransferase genes in invertebrates, it has also been proposed that DNA methylation could provide a molecular mechanism for ecological adaptation. We have now analyzed the methylome of the desert locust, Schistocerca gregaria, which represents an organism with a high degree of phenotypic plasticity. Using genome-scale bisulfite sequencing, we show here that the S. gregaria methylome is characterized by CpG- and exon-specific methylation and thus shares two major features with other animal methylomes. In contrast to other invertebrates, however, overall methylation levels were substantially higher and a significant fraction of transposons was methylated. Additionally, genic sequences were densely methylated in a pronounced bimodal pattern, suggesting a role for DNA methylation in the regulation of locust gene expression. Our results thus uncover a unique pattern of genome methylation in locusts and provide an important foundation for investigating the role of DNA methylation in locust phase polyphenism.
DNA 甲基化是一种广泛保守的表观遗传修饰。对各种生物体中全基因组范围的 DNA 甲基化模式的分析表明，动物甲基组的主要特征是广泛保守的。然而，基于无脊椎动物中 DNA 甲基转移酶基因的变异，也有人提出 DNA 甲基化可以为生态适应提供一种分子机制。我们现在分析了具有高度表型可塑性的沙漠蝗 Schistocerca gregaria 的甲基组。使用全基因组亚硫酸氢盐测序，我们在这里表明，S. gregaria 甲基组的特征是 CpG 和外显子特异性甲基化，因此与其他动物甲基组有两个主要特征。然而，与其他无脊椎动物不同的是，整体甲基化水平显著较高，并且转座子的很大一部分被甲基化。此外，基因序列呈明显的双峰模式密集甲基化，表明 DNA 甲基化在调节蝗虫基因表达中的作用。因此，我们的研究结果揭示了蝗虫中独特的基因组甲基化模式，并为研究 DNA 甲基化在蝗虫相位多态性中的作用提供了重要基础。
