Name: Elaine N.
I am interested in stem cell research and need some help
in clarifying two different types of stem cells that I have come across
in my research material. The two types are embryonic stem cells and the
other is pluripotent stem cells. I do not know what the difference
between the two are.
The pluri-potent stem cell is simply a cell that gives rise to many other
types of cells. They are found in all stages of an animal. You have them
in your bone marrow. Embryonic stem cells are also pluri-potent but are
typically derived from embryos. They both hold promise for generating all
sorts of cells.
Peter Faletra Ph.D.
Office of Science
Department of Energy
Elaine, You are going to hate me, because I am going to add a few more terms
to the mix :)
Embryonic stem cells are cells that are in embryos (obviously) that have the
capacity to develop into many different types of cells (nerve, muscle, etc.).
In the beginning, they have virtually unlimited opportunities to develop into
almost any type of cell. Historically, they were said to be "totipotent." As
development continues, their options begin to narrow a bit; they can develop
into say, a few different types of cells, depending on how they are
influenced. At this point, they have historically been termed "pluripotent."
Eventually, they are "determined" to be a certain specific type of cell. They
may not look like the final cell type yet, but the dye has been cast, so to
speak. Even later, they "differentiate," meaning they develop to where they
actually look and act like the type of cell they were determined to be
earlier in development.
Each of these stages is influenced by the molecules present in the embryo.
Some of these molecules (usually proteins) were made by the mother and
packaged into the unfertilized egg, and others were made by the young embryo
The problem these days is that terms are bandied about in the popular press
that may not be totally accurate. From your question, I think it is safe to
say that you are reading about embryonic stem cells that are pluripotent.
Paul Mahoney, Ph.D.
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Update: June 2012