title: Irreversible gene repression model for control of development.
abstract: As the pluripotent cells of early embryos differentiate, each progressively loses the potency to develop into several phenotypes. Ultimately, each cell becomes irreversibly restricted to the expression of a single phenotype. Although in many instances details regarding those restriction events are well known, there is little information concerning the nature of the gene transcription changes involved. A model that accounts for the diminution of developmental potential as resulting from progressive, irreversible repression of previously active genes is presented. A scheme of progressive gene repression, rather than selective gene activation, is most consistent with observations from experimental embryology as well as from more recent biochemical experimentation.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000502:physiology; D003593:Cytoplasm / Q000502:physiology; D004777:Environment; D004794:Enzyme Repression; D005121:Extremities / Q000502:physiology; D005796:Genes; D008954:Models, Biological; D009024:Morphogenesis; D010641:Phenotype; D012038:Regeneration; D014158:Transcription, Genetic