Cell Differentiation
After fertilization and as the cell divides, the resulting DNA folds onto histones as chromatins, coils of chromosomes on proteins, and can do so in many different ways that determine the characteristic of a cell type that makes it different from another, though genetically identical, and this is dependent on the niche(environmental conditions). Genes for Histone acetylase(remodeler), DNA methylases and ribonucleases, which determine the fate of the cell will all be expressed in the totipotent or pluri-potent stem cell to bring about the possible arrangements. But what pushes(drives) the cell to specialize will be the master genes, genes that code for the transcription factors that regulate other genes being expressed in each cell. Transcription factors are usually synthesized, then expressed on the cell surface as receptors or antennae. They respond to environmental cues such as steroid hormones, cytokines and other growth factors, light, heat and contact, hence the importance of th...