"Knowing the parts of isolated entities is not enough. A musical metaphor expresses it best: molecular biology could read notes in the score, but it couldn’t hear the music." - Carl Woese, A New Biology for a New Century (2004)
"Chance events—injuries, infections, infatuations; the haunting trill of that particular nocturne—impinge on one twin and not on the other. Genes are turned on and off in response to these events, as epigenetic marks are gradually layered above genes, etching the genome with its own scars, calluses, and freckles." - Siddhartha Mukherjee, The Gene: An Intimate History (2015)
Nothing about development in multicellular organisms makes sense except in the light of epigenetics. It captures the remarkable capacity for cells with identical genomes, such as the billion or so cells in our bodies, to differentially regulate their genes and retain these patterns of expression throughout the life of the organism. This process of establishing epigenetic gene expression states is intricately tied to how the genome is organized and packaged by proteins called histones. Molecular labels in the form of histone modifications constitute a major pathway that bookmarks gene expression states in eukaryotic cells without alterations to the underlying DNA sequence. Using yeast as a model system, my laboratory takes a highly interdisciplinary perspective that synthesizes genetics, biochemistry and biophysical approaches to define how cells encode and transmit heritable patterns of gene expression.