Dr. Condic Explains Why Reprogrammed Cells Are Not Embryos

This is a great read for anyone who worries about the various reprogramming techniques for creating stem cells. I would include myself in that category. Dr. Maureen Condic, Associate Professor of Neurobiology and Anatomy at the University of Utah School of Medicine, makes an excellent case at Public Discourse that stem cells are not embryos.  She highlights the important distinction between true "totipotency" that can give rise to a developing organism and the common usage of "totipotent" which is often employed to describe a cell that can differentiate into all the different tissue types including placenta. The former is a zygote that has the ability to become a multi-celled embryo, then a fetus and so on. The latter are just cells that can become all different cell types, but lack the organizational ability of true totipotency. Dr. Condic writes:The term “totipotent” is used in the scientific literature in two radically different ways. The strict sense of totipotency refers to a one-cell embryo or zygote that is “capable of developing into a complete organism.” The second, weaker sense of totipotency refers to the ability of a cell to differentiate into any of the cells or tissues of the body, including cells of the placenta. A zygote is “totipotent” in both senses, yet pluripotent stem cells are “totipotent” only in the second sense.Dr. Condic reveals that stem cells, even ones that can become all the tissue types of the body and placenta a...
Source: Mary Meets Dolly - Category: Geneticists and Genetics Commentators Tags: Induced Pluripotent Stem Cells Source Type: blogs