Discovery of Reversible "Master Switch" Sheds Light on Regulation of Developmental Genes
Credit: Michael Worful
In a paper published in Genes & Development, BWH principal investigator Mitzi Kuroda, PhD, and her team identified a reversible "master switch" on most developmental genes. The team unearthed this biological insight through studies in the fruit fly -- a powerful model organism for studying how human genes are organized and function.
The human genome contains billions of DNA "letters," that can only be read as words, phrases and sentences with the help of proteins that, metaphorically, mark the DNA with punctuation. Together, the DNA-protein combinations form chromatin which provides the essential annotation for gene transcription. However, it is still not understood how the annotation and readout of a single genome differs across cell types. The differences are crucial for normal development and are mutated in cancer. Currently, it is thought that different combinations of proteins act at each of the thousands of genes, and deciphering the numerous complex patterns is a difficult task.
In Kang et al., the Kuroda lab identifies a reversible "master switch" that sits on potentially all developmental genes in a model organism, the fruit fly. Their bivalent master switch model provides a conceptually simple explanation for how each developmental step is made along the path to different cell types, dependent on cell type-specific proteins, but acting through this common module.
In this case the fly model is likely to extend and synergize with seminal work by Harvard Medical School professor Brad Bernstein, MD, PhD, and colleagues on the regulation of key developmental genes in mammalian embryos.
This article has been republished from materials provided by Brigham and Women's Hospital. Note: material may have been edited for length and content. For further information, please contact the cited source.
Kang, H., Jung, Y. L., McElroy, K. A., Zee, B. M., Wallace, H. A., Woolnough, J. L., ... & Kuroda, M. I. (2017). Bivalent complexes of PRC1 with orthologs of BRD4 and MOZ/MORF target developmental genes in Drosophila. Genes & Development, 31(19), 1988-2002.
Since Darwin's era, scientists have wondered how flightless birds like emus, ostriches, kiwi, cassowaries and others are related, and for decades the assumption was that they must all share a common ancestor who abandoned the skies for a more grounded life. A team of Harvard researchers believes they may now have part of the answer.READ MORE
Victims of bullying in secondary school have dramatically increased chances of mental health problems and unemployment in later life. New research reveals stark consequences a decade on for pupils subjected to bullying. Those who are the victims of persistent or violent bullying suffer the worst consequences.READ MORE
Why is it that we can get sad, when we see someone else crying? Why is it that we wince, when a friend cuts his finger? Researchers from the Netherlands Institute for Neuroscience have found that the rat brain activates the same cells when they observe the pain of others as when they experience pain themselves.READ MORE