Researchers at University of California San Diego have produced a single-cell chromatin atlas for the human genome. Chromatin is a complex of DNA and protein found in eukaryotic cells; regions of chromatin at key gene regulatory elements appear in open configurations within certain cell nuclei. Precisely delineating these accessible chromatin regions in cells of different human tissue types would be a major step toward understanding the role of gene regulatory elements (non-coding DNA) in human health or disease.
Although the human genome was sequenced 20 years ago, there is still much interpreting left to do.
“A major reason is that the majority of the human DNA sequence, more than 98 percent, is non-protein-coding, and we do not yet have a genetic code book to unlock the information embedded in these sequences,” said Bing Ren, director of the Center for Epigenomics, professor of cellular and molecular medicine at UC San Diego School of Medicine.
Working with mice, Ren and collaborators turned their attention to a single-cell atlas of chromatin in the human genome.
They applied assays to more than 600,000 human cells sampled from 30 adult human tissue types from multiple donors, then integrated that information with similar data from 15 fetal tissue types to reveal the status of chromatin at approximately 1.2 million candidate cis-regulatory elements in 222 distinct cell types.
Ren said the new findings identify disease-trait-relevant cell types for 240 multi-genic traits and diseases, and annotate the risk of noncoding variants.
“We believe that this resource will greatly facilitate the study of mechanism across a broad spectrum of human diseases for many years to come.”