The program of gene expression during development of plants and animals is controlled by epigenetic mechanisms . This control can be accomplished by methylation / demethylation of DNA or methylation / demethylation of specific lysines in histones H3 and H4 . Polycomb group proteins ( PcG ) is responsible for maintaining repressed genes and the group of proteins tritorax ( trxG ) genes maintained in the active state . Methylation of lysine 9 and 27 in histone H3 lysine 20 methylation and histone H4 results in gene silencing .

The role of communication symplastowej as part of an information exchange system between the cells of the body plant during its growth and development has been described as an example embriogenezyArabidopsis thaliana. Studies in recent years have demonstrated fact that one of the mechanisms of regulation of developmental processes are changes in the permeability of plasmodesmata between the cells of the embryo.