One major form of epigenetic controls is methylation of areas of DNA,which modifies the expression of the DNA code. It is now found that a certain protein maintains the methlyation and it not just DNA reduplication that causes the retention of the methyl groups. Again, the genetic controls are shown to be more and more complex. -http://phys.org/news/2012-09-scientists-link-players-epigenetic-code.html-Also see how incRNA can play a role resulting in heritable changes:-http://the-scientist.com/2012/10/01/the-epigenetic-lnc/