EMBL: Chromatin usage reveals developmental trajectories
Information (arrows) emanating out of chromatin to give rise to different cell types. IMAGE: Campbell Medical Illustration
Both cell type and developmental stage can be deduced from measurements of chromatin accessibility in thousands of single cells, researchers at EMBL and the University of Washington show. They used this approach to uncover how cells in developing embryos regulate their identity as they decide what kind of cell to become. Nature publishes the results on March 14.
This new and more systematic approach allows researchers to analyse all the different cell types in an embryo at the same time, and importantly at a single cell resolution. “I expect this approach to save labs around the world lots of time,” says Eileen Furlong, who co-led the work at EMBL in Heidelberg with Jay Shendure at the University of Washington School of Medicine in Seattle.
Previously, a researcher would have to first isolate the various cell types, and then investigate the chromatin of each type in separate batches. That lengthy method provided an averaged view across thousands of cells of a given cell type. “Previous studies have used differences in RNA content to identify cell types and their developmental trajectories,” says Shendure. “Here, we instead measure the state of chromatin in single cells, which contains the regulatory program that governs how and when RNAs are expressed in each cell.”
“For the first time, we have looked upstream at how these expression signatures are regulated and therefore drive single cell trajectories during early development,” Furlong adds.
RESEARCH ARTICLE Cusanovich, Reddington, Garfield et al., The cis-regulatory dynamics of embryonic development at single cell resolution. Nature, published online 14 March 2018. DOI: 10.1038/nature25981
Read more here.