Keeping to the margins of the nucleus, many genes seem to be left out of the cell development dance. These genes, like wallflowers at the prom, might even appear to be physically tethered. In fact, according to a new study, they are physically tethered—but not always. There are times when the tethers are released and seemingly shy genes are drawn into the whirl of activity that drives cell differentiation. These genes may even alter the choreography within stem cells that determines whether they become a muscle cell, say, or a nerve cell.

The tether is an epigenetic enzyme called histone deacetylase (Hdac3). It organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. In other words, it attaches DNA to the nuclear periphery.

This connection—not just the physical connection, but also the connection to lineage restriction—was uncovered by scientists based at the Perelman School of Medicine …