External temperature change has been shown to modify epigenetic patterns, such as DNA methylation, which regulates gene expression. DNA methylation is heritable, and as such provides a mechanism to convey environmental information to subsequent generations. Studies on epigenetic response to temperature increase are still scarce in wild mammals, even more so studies that compare tissue-specific epigenetic responses. Here, we aim to address differential epigenetic responses on a gene and gene pathway level in two organs, liver and testis. We chose these organs, because the liver is the main metabolic and thermoregulation organ, and epigenetic modifications in testis are potentially transmitted to the F2 generation. We focused on the transmission of DNA methylation changes to naive male offspring after paternal exposure to an ambient temperature increase of 10 °C, and investigated differential methylated regions of sons sired before and after the paternal exposure using Reduced Representation Bisulfite Sequencing. We detected both a highly tissue-specific epigenetic response, reflected in genes involved in organ-specific metabolic pathways, and a more general regulation of single genes epigenetically modified in both organs. We conclude that genomes are context-specifically differentially epigenetically regulated in response to temperature increase. These findings emphasize the epigenetic relevance in cell differentiation, which is essential for the specific function(s) of complex organs, and is represented in a diverse molecular regulation of genes and gene pathways. The results also emphasize the paternal contribution to adaptive processes.

外部温度变化已显示出可改变表观遗传模式，例如调节基因表达的DNA甲基化。DNA甲基化是可遗传的，因此提供了将环境信息传达给后代的机制。在野生哺乳动物中，对于温度升高的表观遗传反应的研究仍然很少，比较组织特异性表观遗传反应的研究更是如此。在这里，我们旨在解决肝脏和睾丸这两个器官在基因和基因途径水平上的不同表观遗传反应。我们选择这些器官是因为肝脏是主要的代谢和体温调节器官，而睾丸的表观遗传修饰可能会传递给F2代。我们将重点放在父本暴露于环境温度升高10°C后向幼稚雄性后代的DNA甲基化变化的传递上，并使用减少的代表性亚硫酸氢盐测序研究父本暴露前后子代的差异甲基化区域。我们既检测到了高度组织特异性表观遗传反应，反映了参与器官特异性代谢途径的基因，又检测了在两个器官中表观遗传修饰的单个基因的更一般的调控。我们得出的结论是，基因组是响应温度升高而受到上下文特异性差异表观遗传调控的。这些发现强调了细胞分化中的表观遗传学相关性，这对于复杂器官的特定功能至关重要，并以多种多样的基因和基因途径分子调控方式出现。结果还强调了父亲对适应性过程的贡献。