Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
Institute of Clinical Molecular Biology, Kiel University, Kiel, Germany.
Sci Adv. 2020 Mar 20;6(12):eaaz1138. doi: 10.1126/sciadv.aaz1138. eCollection 2020 Mar.
Epigenetic inheritance has been proposed to contribute to adaptation and acclimation via two information channels: (i) inducible epigenetic marks that enable transgenerational plasticity and (ii) noninducible epigenetic marks resulting from random epimutations shaped by selection. We studied both postulated channels by sequencing methylomes and genomes of Baltic three-spined sticklebacks () along a salinity cline. Wild populations differing in salinity tolerance revealed differential methylation (pop-DMS) at genes enriched for osmoregulatory processes. A two-generation experiment demonstrated that 62% of these pop-DMS were noninducible by salinity manipulation, suggesting that they are the result of either direct selection or associated genomic divergence at cis- or trans-regulatory sites. Two-thirds of the remaining inducible pop-DMS increased in similarity to patterns detected in wild populations from corresponding salinities. The level of similarity accentuated over consecutive generations, indicating a mechanism of transgenerational plasticity. While we can attribute natural DNA methylation patterns to the two information channels, their interplay with genomic variation in salinity adaptation is still unresolved.
（i）可诱导的表观遗传标记，使跨代可塑性，和（ii）非诱导的表观遗传标记，由随机的表观突变形成，并受选择影响。我们通过对波罗的海三刺鱼（）沿盐度梯度进行甲基组和基因组测序，研究了这两个假定的通道。在耐盐性方面存在差异的野生种群在富含渗透调节过程的基因上表现出差异甲基化（pop-DMS）。一个两代实验表明，这些 pop-DMS 中有 62%不能通过盐度处理诱导，这表明它们是直接选择的结果，或者是顺式或反式调控位点的相关基因组差异的结果。其余三分之二的可诱导 pop-DMS 与对应盐度的野生种群中检测到的模式相似性增加。相似性的水平在连续几代中逐渐增强，表明存在跨代可塑性的机制。虽然我们可以将自然 DNA 甲基化模式归因于两个信息通道，但它们与盐度适应过程中基因组变异的相互作用仍未解决。
