Topologically associating domains (TADs), CTCF loop domains, and A/B compartments have been identified as important structural and functional components of 3D chromatin organization, yet the relationship between these features is not well understood. Using high-resolution Hi-C and HiChIP, we show that Drosophila chromatin is organized into domains we term compartmental domains that correspond precisely with A/B compartments at high resolution. We find that transcriptional state is a major predictor of Hi-C contact maps in several eukaryotes tested, including C. elegans and A. thaliana. Architectural proteins insulate compartmental domains by reducing interaction frequencies between neighboring regions in Drosophila, but CTCF loops do not play a distinct role in this organism. In mammals, compartmental domains exist alongside CTCF loop domains to form topological domains. The results suggest that compartmental domains are responsible for domain structure in all eukaryotes, with CTCF playing an important role in domain formation in mammals.

拓扑关联域（TAD），CTCF环域和A / B区域已被确定为3D染色质组织的重要结构和功能组件，但这些特征之间的关系尚未得到很好的理解。使用高分辨率的Hi-C和HiChIP，我们显示了果蝇染色质被组织成我们称为隔室区域的区域，这些区域与高分辨率下的A / B隔室精确对应。我们发现，在包括C. elegans和A. thaliana在内的几种真核生物中，转录状态是Hi-C接触图的主要预测因子。建筑蛋白通过减少果蝇相邻区域之间的相互作用频率来隔离区隔结构域，但CTCF环在这种生物中没有扮演独特的角色。在哺乳动物中，隔室结构域与CTCF环结构域并存，以形成拓扑结构域。结果表明，间隔域负责所有真核生物的域结构，而CTCF在哺乳动物的域形成中起着重要作用。