Unraveling mystery in 'histone code' shows how gene activity is inherited

Every cell in our body has exactly the same DNA, yet every cell is different. The genetic code carried in our DNA provides instructions for cells to manufacture specific proteins. A second code, carried by histone proteins bound to DNA, determines which genes are activated in particular cells. Researchers have found that the slightest variation in a histone protein can have dramatic effects on how the genes encoded in our DNA are used.