A more nuanced genetic code: Rules governing expression of developmental genes in embryonic stem cells
This paradoxical state — akin to figuring out how to navigate a red and green traffic signal — has since undergone scrutiny by labs worldwide. What has been postulated is that the control regions (or promoters) of some genes, particularly those critical for development during the undifferentiated state, stay "poised" for plasticity by communicating with both activating and repressive histones, a state biologists term "bivalency." A study by researchers at the Stowers Institute for Medical Research now revisits that notion. In this week’s advance online edition of the journal Nature Structural and Molecular Biology, a team led by Investigator Ali Shilatifard, Ph.D., identifies the protein complex that implements the activating histone mark specifically at "poised" genes in mouse embryonic stem (ES) cells, but reports that its loss has little effect on developmental gene activation during differentiation. …