Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
Department of Biology, York University, Toronto, Canada.
BMC Biol. 2019 Apr 10;17(1):30. doi: 10.1186/s12915-019-0646-4.
Epigenetic mechanisms play fundamental roles in brain function and behavior and stressors such as social isolation can alter animal behavior via epigenetic mechanisms. However, due to cellular heterogeneity, identifying cell-type-specific epigenetic changes in the brain is challenging. Here, we report the first use of a modified isolation of nuclei tagged in specific cell type (INTACT) method in behavioral epigenetics of Drosophila melanogaster, a method we call mini-INTACT.
Using ChIP-seq on mini-INTACT purified dopaminergic nuclei, we identified epigenetic signatures in socially isolated and socially enriched Drosophila males. Social experience altered the epigenetic landscape in clusters of genes involved in transcription and neural function. Some of these alterations could be predicted by expression changes of four transcription factors and the prevalence of their binding sites in several clusters. These transcription factors were previously identified as activity-regulated genes, and their knockdown in dopaminergic neurons reduced the effects of social experience on sleep.
Our work enables the use of Drosophila as a model for cell-type-specific behavioral epigenetics and establishes that social environment shifts the epigenetic landscape in dopaminergic neurons. Four activity-related transcription factors are required in dopaminergic neurons for the effects of social environment on sleep.
表观遗传机制在大脑功能和行为中起着基础性作用,社会隔离等应激源可以通过表观遗传机制改变动物行为。然而,由于细胞异质性,识别大脑中特定细胞类型的表观遗传变化具有挑战性。在这里,我们报告了改良的特定细胞类型细胞核标记分离(INTACT)方法在黑腹果蝇行为表观遗传学中的首次应用,我们称之为 mini-INTACT。
使用 mini-INTACT 纯化的多巴胺能细胞核进行 ChIP-seq,我们在社会隔离和社会丰富的雄性果蝇中鉴定了表观遗传特征。社会经验改变了参与转录和神经功能的基因簇中的表观遗传景观。这些变化中的一些可以通过四个转录因子的表达变化和它们在几个簇中的结合位点的普遍性来预测。这些转录因子以前被鉴定为活性调节基因,它们在多巴胺能神经元中的敲低降低了社会经验对睡眠的影响。
我们的工作使 Drosophila 成为一种用于特定细胞类型行为表观遗传学的模型,并证实社会环境改变了多巴胺能神经元中的表观遗传景观。四个与活性相关的转录因子在多巴胺能神经元中是社会环境对睡眠影响所必需的。