Embryonic stem cells: a perspective.
Embryonic stem (ES) cells are proliferating tissue-culture cells which are embryonic in origin and retain the full lineage and differentiative capacity of the early mammalian embryo. Only mouse ES cells have been fully characterized but similar cultures have been isolated from numbers of other mammalian embryos including, notably, human. ES cells can differentiate either in vivo in the context of an embryo or equivalently in vitro. Their ability to undergo genetic alteration and selection in vitro followed by embryonic development in vivo has led to their extensive use as a vector for mammalian genetic engineering. This is not an application for human ES cells but their ability to differentiate in vitro into a plethora of specific tissue precursors has led to scenarios for their use in cellular and tissue engineering therapies. Ethical and practical problems for the provision of ad hominem human ES cells remain. Knowledge from the mouse system may aid our understanding of the relationship between ES cells and embryos.
Evans
Martin
M
Cardiff School of Biosciences, Cardiff University, PO Box 911, Cardiff CF10 3US, UK.
D000818:Animals; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology; D006801:Humans; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology