Table_1_Transgenerational Epigenetic Inheritance Under Environmental Stress by Genome-Wide DNA Methylation Profiling in Cyanobacterium.DOCX

Epigenetic modifications such as DNA methylation are well known as connected with many important biological processes. Rapid accumulating evidence shows environmental stress can generate particular defense epigenetic changes across generations in eukaryotes. This transgenerational epigenetic inheritance in animals and plants has gained interest over the last years. Cyanobacteria play very crucial role in the earth, and as the primary producer they can adapt to nearly all diverse environments. However, few knowledge about the genome wide epigenetic information such as methylome information in cyanobacteria, especially under any environment stress, was reported so far. In this study we profiled the genome-wide cytosine methylation from a model cyanobacterium Synechocystis sp. PCC 6803, and explored the possibility of transgenerational epigenetic process in this ancient single-celled prokaryote by comparing the DNA methylomes among normal nitrogen medium cultivation, nitrogen starvation for 72 h and nitrogen recovery for about 12 generations. Our results shows that DNA methylation patterns in nitrogen starvation and nitrogen recovery are much more similar with each other, significantly different from that of the normal nitrogen. This study reveals the difference in global DNA methylation pattern of cyanobacteria between normal and nutrient stress conditions and reports the evidence of transgenerational epigenetic process in cyanobacteria. The results of this study may contribute to a better understanding of epigenetic regulation in prokaryotic adaptation to and survive in the ever changing environment.

表观遗传修饰，如DNA甲基化，因其与众多重要生物学过程紧密相连而广为人知。大量迅速累积的证据表明，环境应激能够在真核生物中引发跨代特定的防御性表观遗传变化。近年来，动物与植物中的这种跨代表观遗传遗传在科学界引起了广泛关注。蓝细菌在地球上扮演着至关重要的角色，作为初级生产者，它们能够适应几乎所有多样化的环境。然而，关于蓝细菌的全基因组表观遗传信息，例如甲基化组信息，特别是在任何环境应激条件下，目前所知甚少。在本研究中，我们对模式蓝细菌 Synechocystis sp. PCC 6803 的全基因组胞嘧啶甲基化进行了分析，并通过比较正常氮培养基培养、72小时的氮饥饿以及大约12代的氮恢复过程中的DNA甲基化组，探讨了这种古老的真核原核生物中跨代表观遗传过程的可能性。我们的结果显示，氮饥饿和氮恢复条件下的DNA甲基化模式彼此之间具有更高的相似性，与正常氮条件下的甲基化模式显著不同。本研究揭示了蓝细菌在正常和营养应激条件下的全球DNA甲基化模式的差异，并报告了蓝细菌中跨代表观遗传过程的证据。本研究的结果可能有助于更深入地理解原核生物在环境不断变化的环境中适应和生存的表观遗传调控。