Single-Cell Atlas Simultaneously Maps 3D Genome Architecture and DNA Methylation
Researchers at the Salk Institute and the Arc Institute have released the first body-wide single-cell atlas mapping two vital epigenetic systems. By measuring three-dimensional genome folding and DNA methylation simultaneously within 86,689 individual cells from 16 human tissues, the team identified 35 major cell types and 206 subtypes.
This project, supported by the NIH 4D Nucleome program, provides a new way to understand how the genome is organized to regulate gene expression. While DNA methylation and 3D genome folding generally align, the study uncovered instances where they disagree. In skeletal muscle and peripheral nervous system cells, the 3D genome architecture often shifts before the methylation patterns catch up, suggesting these processes operate on different time scales during cell development.
Most genetic variants associated with disease exist in noncoding regions of the genome. These regions do not contain instructions for proteins, making their role in disease difficult to trace. This atlas provides a map to connect noncoding variations to the genes they influence in specific tissues. Researchers linked specific genetic risks for atrial fibrillation, blood-glucose regulation, and even balding to their corresponding cell types.
Beyond basic biology, this dataset offers a critical resource for training artificial intelligence models. As AI becomes a standard tool for predicting how genetic variants impact human health, high-quality, cell-resolved data becomes the primary bottleneck for accuracy. This public database provides that information, including 195 billion methylation measurements and 18 billion chromatin contacts.
Early findings from the atlas are already changing medical consensus. A study using this data found that microglia in the brain are replaced by cells resembling blood monocytes as people age, challenging the belief that these immune cells persist unchanged from birth. The public web browser allows scientists to look at every tissue type profiled to see how genome organization varies across the body.