Year: 2012
Type: book-chapter
Abstract: 1.1 Stemness The fertilized egg, also known as the zygote, is a cell of total potential and plasticity and gives rise to the embryo and extra-embryonic tissues, and ultimately the whole adult organism. This property has since been termed totipotency, although the transition from fertilized egg to differentiated cells of the adult tissues (somatic cells) is not direct, progressing instead through lineages of successively more differentiated and committed intermediates towards the final cell type. Thus, the zygote gives rise to the trophoblast cells and inner cell mass (ICM) of the blastocyst stage embryo, the ICM gives rise to the primordial cells committed to the ectodermal, mesodermal and endodermal lineages. To give an example lineage, the ectoderm cells give rise to the neural crest stem cells, then neural stem cells, oligodendrocyte precursors, and finally oligodendrocytes which myelinate and form the white matter of the central nervous system. Each step is more specialized and less plastic than the base or ‘stem’ of the branch before it. Unlike the totipotent zygote, these ‘stem cells’ retain the ability to self-renew in addition to their plasticity. In addition to giving rise to somatic tissues during embryogenesis, the biological role of stem cells in an adult organism is to regenerate tissues lost to injury, disease or age.
Source: InTech eBooks
DOI: 10.5772/19440
Authors: Ambrose Jon, Vimal Selvaraj
Institution: Cornell University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
OpenAlex ID: W1481838907