title: Organoids and the genetically encoded self-assembly of embryonic stem cells.
abstract: Understanding the mechanisms of early embryonic patterning and the timely allocation of specific cells to embryonic regions and fates as well as their development into tissues and organs, is a fundamental problem in Developmental Biology. The classical explanation for this process had been built around the notion of positional information. Accordingly the programmed appearance of sources of Morphogens at localized positions within a field of cells directs their differentiation. Recently, the development of organs and tissues from unpatterned and initially identical stem cells (adult and embryonic) has challenged the need for positional information and even the integrity of the embryo, for pattern formation. Here we review the emerging area of organoid biology from the perspective of Developmental Biology. We argue that the events underlying the development of these systems are not purely linked to self-organization, as often suggested, but rather to a process of genetically encoded self-assembly where genetic programs encode and control the emergence of biological structures.
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge, United Kingdom.
authors.forename: David A
authors.initials: DA
authors.lastname: Turner
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Baillie-Johnson
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Martinez Arias
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D015509:Developmental Biology / Q000379:methods; D053595:Embryonic Stem Cells / Q000502:physiology*; D006801:Humans; D009024:Morphogenesis / Q000235:genetics* / Q000502:physiology*; D009940:Organoids / Q000502:physiology*
keywords: development; organoids; positional information; reaction-diffusion; self-assembly; self-organization